US3669899A
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Microcapsular opacifier system
Assignee: US Plywood Champion Papers Inc
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Filing: 1969-04-29
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Granted: 1972-06-13
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Expires: 1989-04-29
Abstract
Abstract Opacifiers comprising air-containing microcapsules having an average particle diameter of predetermined size with pigment particles incorporated in the microcapsular structure provide highly opaque surfaces when coated onto and/or incorporated into fibrous and non-fibrous substrates. The opacifiers are produced by heating liquid-containing precursor microcapsules, which contain the pigment particles in their structure, at temperatures sufficient to expel the liquid and provide air in the microcapsules. The microcapsular opacifiers have an average particle diameter below about 2 microns.
Inventors
- 👤 Anthony E Vassiliades
- 👤 Edward F Nauman
- 👤 Shrenik Shroff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:34
CPC Classifications
D; D21; D21H; D21H19/00; D21H19/36; D21H19/38; D21H19/42; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/08; B01J13/20; B01J13/203; B29; B29D; B29D7/00; B29D7/01; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2989
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
19 words
Microcapsular opacifiers as defined in claim 1 having an average particle diameter of between about 0.10 and 1.0 micron.
Claim 2
Dependent Claim
20 words
Microcapsular opacifiers as defined in claim 2 having an average particle diameter of between about 0.25 and about 0.8 micron.
Claim 3
Dependent Claim
15 words
Microcapsular opacifiers as defined in claim 1 wherein said pigment is an inorganic opacifying pigment.
Claim 4
Dependent Claim
26 words
Microcapsular opacifiers as defined in claim 1 wherein said pigment is a member selected from the group consisting of TiO2, BaSO4, ZnO, CaCO3, and Al2O3 .3H2O.
Claim 5
Dependent Claim
12 words
Microcapsular opacifiers as defined in claim 5 wherein said pigment is TiO2.
Claim 6
Dependent Claim
21 words
Microcapsular opacifiers as defined in claim 6 wherein said TiO2 has a particle size of about 0.1 and about 0.35 micron.
Claim 7
Dependent Claim
15 words
Microcapsular opacifiers as defined in claim 5 wherein said walls comprise a formaldehyde condensation product.
Claim 8
Dependent Claim
51 words
Microcapsular opacifiers as defined in claim 5 wherein said pigment is BaSO4. 10 Microcapsular opacifiers consisting essentially of discrete substantially spherical, air-containing microcapsules having substantially continuous, organic, polymeric, solid walls and an average particle diameter of below about 2 microns, said microcapsules additionally having pigment particles protruding through said capsule walls.
Claim 9
Dependent Claim
20 words
Microcapsular opacifiers as defined in claim 10 having an average particle diameter of between about 0.1 and about 1.0 micron.
Claim 10
Dependent Claim
20 words
Microcapsular opacifiers as defined in claim 11 having an average particle diameter of between about 0.25 and about 0.8 micron.
Claim 11
Dependent Claim
24 words
Microcapsular opacifiers as defined in claim 12 wherein said pigment is a member selected from the group consisting of TiO2, BaSoO4, CaCO3, and Al2O3.3H2O.
Claim 12
Dependent Claim
12 words
Microcapsular opacifiers as defined in claim 13 wherein said pigment is TiO2.
Claim 13
Dependent Claim
12 words
Microcapsular opacifiers as defined in claim 13 wherein said pigment is BaSO4.
Claim 14
Dependent Claim
12 words
Microcapsular opacifiers as defined in claim 13 wherein said pigment is CaCO3.
Claim 15
Dependent Claim
12 words
Microcapsular opacifiers as defined in claim 10 wherein said pigment is clay.
Claim 16
Dependent Claim
41 words
Microcapsular opacifiers consisting essentially of discrete, substantially spherical, air-containing microcapsules having substantially continuous, organic, polymeric, solid walls and an average particle diameter of below about 2 microns, said microcapsules additionally having pigment particles completely encapsulated within the walls of the microcapsules.
Claim 17
Dependent Claim
19 words
Microcapsular opacifiers as defined in claim 18 haVing an average particle diameter of between about 0.10 and 1.0 micron.
Claim 18
Dependent Claim
20 words
Microcapsular opacifiers as defined in claim 19 having an average particle diameter of between about 0.25 and about 0.8 micron.
Claim 19
Dependent Claim
25 words
Microcapsular opacifiers as defined in claim 19 wherein said pigment is a member selected from the group consisting of TiO2, BaSO4, ZnO, CaCO3, and Al3O3.3H2O.
Claim 20
Dependent Claim
12 words
Microcapsular opacifiers as defined in claim 21 wherein said pigment is TiO2.
Claim 21
Dependent Claim
44 words
Microcapsular opacifiers consisting essentially of discrete substantially spherical, air-containing microcapsules having substantially continuous solid walls of methyl cellulose and a formaldehyde condensation product, said microcapsules having an average particle diameter of below about 2 microns and having pigment particles incorporated in the microcapsular structure.
Claim 22
Dependent Claim
14 words
Microcapsular opacifiers as defined in claim 23 wherein said formaldehyde condensation product is melamine-formaldehyde.
Claim 23
Independent Claim
79 words
A method for the production of microcapsular opacifiers which comprises providing discrete, essentially spherical precursor microcapsules having substantially continuous organic, polymeric, solid walls, said microcapsules having an average particle diameter of below about 2 microns and containing a liquid core material, said microcapsules additionally having pigment particles incorporated in the microcapsular structure, and heating said microcapsules to a temperature sufficient to substantially completely drive off said core material from said microcapsules and replace said liquid core material with air.
Claim 24
Dependent Claim
21 words
The method of claim 25 wherein said microcapsules have an average particle diameter of between about 0.10 and about 1.0 micron.
Claim 25
Dependent Claim
21 words
The method of claim 25 wherein said microcapsules have an average particle diameter of between about 0.25 and about 0.8 micron.
Claim 26
Dependent Claim
23 words
The method of claim 25 wherein said pigment is a member selected from the group consisting of TiO2, BaSO4, ZnO, CaCO3, and Al2O3.3H2O.
Claim 27
Dependent Claim
10 words
The method of claim 28 wherein said pigment is TiO2.
Claim 28
Dependent Claim
14 words
The method of claim 25 wherein said liquid core material is a water-immiscible material.
Claim 29
Dependent Claim
27 words
The method of claim 30 wherein said water-immiscible material is an oily material selected from the group consisting of liquid and low melting oils, fats and waxes.
Claim 30
Dependent Claim
25 words
The method of claim 31 wherein the water-immiscible oily material is selected from the group consisting of mineral spirits, chlorinated biphenyl, toluene, styrene and turpentine.
Claim 31
Dependent Claim
13 words
The method of claim 32 wherein said water-immiscible oily material is mineral spirits.
Claim 32
Dependent Claim
13 words
The method of claim 32 wherein said water-immiscible oily material is chlorinated biphenyl.
Claim 33
Dependent Claim
14 words
The method of claim 25 wherein said liquid core material is a water-miscible material.
Claim 34
Independent Claim
198 words
A method for the production of microcapsular opacifiers which comprises providing precursor microcapsules by admixing inorganic pigment particles and A. a water-immiscible oily material selected from the group consisting of liquid and low melting oils, fats and waxes; B. an amphiphilic emulsifying agent; C. a solution comprising a hydrophobic, thermoplastic resin as the solute, said resin not having appreciable solubility in the oily material, and a water-and oil-miscible organic liquid as the solvent, said thermoplastic resin being capable of being separated in solid particle form from solution upon dilution with water; D. water in a quantity sufficient to cause the separation of said polymeric resin from solution, the sequence of said admixing being such that said resin separates from solution in solid particle form about a nucleus of oil-in-water droplets upon dilution with water as the final operation of said process, which dilution takes place slowly and under conditions of brisk agitAtion, said precursor microcapsules having an average particle diameter of below about 2 microns, and heating said precursor microcapsules to a temperature sufficient to completely drive off said liquid core material from said precursor microcapsules thereby providing air-containing microcapsules having pigment particles incorporated in the microcapsular structure.
Claim 35
Independent Claim
175 words
A method for the production of microcapsular opacifiers which comprises providing precursor microcapsules by admixing inorganic pigment particles and A. a water-immiscible oily material selected from the group consisting of liquid and low melting oils, fats and waxes; B. an amphiphilic emulsifying agent; C. a partially condensed thermosetting resin in an aqueous medium, said resin being capable of being separated from the aqueous medium in solid particle form as a precipitate upon dilution with water; D. water in a quantity sufficient to cause the separation of said polymeric resin from solution, said admixing causing said resin to separate from the aqueous medium in solid particle form as a precipitate about a nucleus of oil-in-water upon dilution with water, which dilution takes place slowly and under conditions of brisk agitation, said precursor microcapsules having an average particle diameter of below about 2 microns, and heating said precursor microcapsules to a temperature sufficient to completely drive off said liquid core material from said precursor microcapsules thereby providing air-containing microcapsules having pigment particles incorporated in the microcapsular structure.
Claim 36
Dependent Claim
176 words
A process for the production of microcapsular opacifiers which comprises providing precursor microcapsules by the process which comprises the steps of: A. forming a primary oil-in-water emulsion, which emulsion comprises a water-immiscible oily material dispersed in the form of microscopic droplets in a colloidal solution of one or more emulsifying agents, at least one of said emulsifying agents being selected from the group consisting of an emulsifying agent possessing cross-linkable groups and an emulsifying agent possessing complexing sites, said emulsion additionally containing inorganic pigment particles; and B. adding to the emulsion system a member selected from the group consisting of an aldehyde, polyvinyl alcohol, gelatin, gumtragacanth, ethanolamine, ethylene diamine, sodium borate, and methylcellulose, the addition taking place slowly and under conditions of brisk agitation, said precursor microcapsules having an average particle diameter of below about 2 microns, and heating said precursor microcapsules to a temperature sufficient to substantially drive off said core material from said precursor microcapsules and replace said core material with air, said air-containing microcapsules having said pigment particle incorporated in the microcapsular structure.
Claim 37
Dependent Claim
17 words
The method of claim 38 wherein said pigment particles protrude through the walls of said air-containing microcapsules.
Claim 38
Dependent Claim
18 words
The method of claim 37 wherein said pigment particles are encapsulated within the walls of the air-containing microcapsules.
Claim 39
Dependent Claim
11 words
The method of claim 37 wherein said resin is melamine formaldehyde.
Claim 40
Dependent Claim
13 words
The method of claim 38 wherein polyvinyl alcohol is added to the emulsion.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-13 | 1975-12-13 | 1976-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-13 | 1979-12-13 | 1980-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-13 | 1983-12-13 | 1984-06-13 | $7700.00 | Window Closed / Lapsed |