US4520073A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure coating of mineral fillers
Assignee: United States Gypsum Co
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Filing: 1983-12-23
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Granted: 1985-05-28
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Expires: 2003-12-23
Abstract
Abstract Mineral filler materials are provided with improved hydrophobic coatings by pressure coating of porous minerals using steam as a carrier for the coating material. Thereby more complete sealing of fissures and cracks in the porous filler materials' surface is provided, resulting in very water-resistant coated particles useful in filling polymeric substrates such as paints, plastics and joint compounds.
Inventors
- 👤 Donald A. Randolph
- 👤 Kenneth R. Watkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:15
CPC Classifications
C; C08; C08K; C08K9/00; C08K9/08; C04; C04B; C04B20/00; C04B20/10; C04B20/1018; C04B20/1051; C08K9/04; C09; C09C; C09C3/00; C09C3/006; C09C3/08; C09C3/10; C09C3/12; C09D; C09D7/00; C09D7/40; C09D7/60; C09D7/61; C09D7/62; C01; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2004/80; C01P2006/00; C01P2006/10; C08K3/00; C08K3/30; C08K3/34; C08K3/36; C08K7/00; C08K7/22; C08K7/24; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2995; Y10T428/2998
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
139 words
A method for the production of a coated mineral filler material having a hydrophobic coating thereon which penetrates, fills and seals fissures and cracks in the surface of the filler and having special utility in enhancing the properties of filled polymeric compositions containing such coated filler which comprises the steps of: (a) introducing porous mineral filler and about 0.01 to about 5.0% by weight based on the weight of mineral filler of a hydrophobic coating material into an agitated pressure vessel; (b) mixing the filler and coating material under low intensity agitation at a temperature between about 32° C. and about 275° C. and introducing steam pressure between about 10 psig and about 100 psig for at least about 1 minute; (c) and drying the wet coated filler to recover a hydrophobic coated mineral filler having enhanced water resistance.
Claim 2
Independent Claim
139 words
A method for the production of a coated mineral filler material having a hydrophobic coating thereon which penetrates, fills and seals fissures and cracks in the surface of the filler and having special utility in enhancing the properties of filled polymeric compositions containing such coated filler which comprises the steps of: (a) introducing porous mineral filler and about 0.01 to about 5.0% by weight based on the weight of mineral filler of a hydrophobic coating material into an agitated pressure vessel; (b) mixing the filler and coating material under low intensity agitation at a temperature between about 32° C. and about 275° C. and introducing steam pressure between about 10 psig and about 100 psig for at least about 1 minute; (c) and drying the wet coated filler to recover a hydrophobic coated mineral filler having enhanced water resistance.
Claim 3
Dependent Claim
108 words
The method of claim 1 in which in step (a) the coating material is selected from the group consisting of long chain aliphatic and dicarboxylic fatty acids having from about 12 to about 24 carbon atoms and their water dispersible base salts, alkanes having from about 2 to 60 carbon atoms and polyalkylenes having molecular weights of from about 280 to 30,000, polyalkylene glycols having a molecular weight from about 700 through about 6000, and organo-functional silicones of the general formula Ri-SiX 3 wherein R is selected from the group consisting of alkoxy and acetoxy and X is selected from the group consisting of halogen, alkoxy and acetoxy.
Claim 4
Dependent Claim
26 words
The method of claim 1 in which in step (2) the coating material is introduced in an amount of about 1% by weight of the filler.
Claim 5
Dependent Claim
20 words
The method of claim 1 in which in step (b) steam pressure is introduced for about 1 through 30 minutes.
Claim 6
Dependent Claim
16 words
The method of claim 1 in which in step (a) the mineral filler is expanded perlite.
Claim 7
Dependent Claim
17 words
The method of claim 1 in which in step (a) the mineral filler is calcium sulfate anhydrite.
Claim 8
Dependent Claim
16 words
The method of claim 1 in which in step (a) the coating material is polydimethyl siloxane.
Claim 9
Dependent Claim
20 words
The method of claim 1 in which in step (a) the coating material is an aqueous dispersion of polydimethyl siloxane.
Claim 10
Dependent Claim
54 words
The method of claim 1 including the steps of (a) introducing expanded perlite particles and about 1-5% by weight of polydimethyl siloxane; and (b) mixing with a stirrer providing about 10 revolutions per minute, at a temperature of about 150° C., and at a steam pressure of about 80 psig for about 20 minutes.
Claim 11
Dependent Claim
27 words
The method of claim 1 in which in step (a) calcium sulfate anhydrite and about 1-5% by weight of polydimethyl siloxane are introduced into the pressure vessel.
Claim 12
Dependent Claim
27 words
The method of claim 1 in which in step (a) calcium sulfate anhydrite and about 1-5% by weight of stearic acid are introduced into the pressure vessel.
Claim 13
Dependent Claim
29 words
The method of claim 1 in which in step (b) the filler and coating material are mixed with a stirrer providing about 5 to about 30 revolutions per minute.
Claim 14
Dependent Claim
93 words
A calcium sulfate filler material having enhanced water resistance and having a hydrophobic coating thereon penetrating, filling and sealing tissures, cracks, and interstices in the surface of the calcium sulfate, said coating comprising the dried solids steam carried and pressure impregnated onto the calcium sulfate by mixing the calcium sulfate and about 0.01% to about 5.0% by weight of hydrophobic coating material under low intensity agitation at a temperature between about 32°-275° C. and steam pressure between about 10-100 psig for at least about 1 minute and drying the wet coated calcium sulfate.
Claim 15
Dependent Claim
93 words
A calcium sulfate filler material having enhanced water resistance and having a hydrophobic coating thereon penetrating, filling and sealing tissures, cracks, and interstices in the surface of the calcium sulfate, said coating comprising the dried solids steam carried and pressure impregnated onto the calcium sulfate by mixing the calcium sulfate and about 0.01% to about 5.0% by weight of hydrophobic coating material under low intensity agitation at a temperature between about 32°-275° C. and steam pressure between about 10-100 psig for at least about 1 minute and drying the wet coated calcium sulfate.
Claim 16
Dependent Claim
13 words
The filler of claim 13 in which the coating material comprises polydimethyl siloxane.
References Cited (Backward Citations)
US4183980A
Cited
US4255489A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |