Patent US4252907A successfully refreshed from Google Patents.
US4252907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing a porous composite material
Assignee: National Institute of Advanced Industrial Science and Technology
•
Filing: 1979-09-04
•
Granted: 1981-02-24
•
Expires: 1999-09-04
Abstract
Abstract A porous composite material includes a porous body formed of a hydrophobic polymer such as polyvinyl chloride and a layer of a hydrophilic polymer such as polyvinyl alcohol provided over at least a portion of the interior surface of each of the pores of the porous body. The composite material is obtained by a process including the steps of dispersing an aqueous solution containing a hydrophilic polymer and a foaming agent into a solution of a hydrophobic polymer in an organic solvent to form an emulsion, removing the water and the organic solvent from the emulsion to obtain a solid, and subjecting the solid to foaming conditions.
Inventors
- 👤 Tatsuo Ogasa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:23
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08J9/04; C08J9/06; Y; Y10; Y10S; Y10S521/00; Y10S521/905; Y10S521/918; Y10S525/00; Y10S525/903
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
82 words
A process for the production of a porous composite material, comprising the steps of: emulsifying an aqueous solution containing a hydrophilic polymer and a foaming agent into a solution of a hydrophobic polymer in an organic solvent to form an emulsion in which liquid particles of said aqueous solution are dispersed in said organic solution; removing said organic solvent and water from said emulsion to obtain a solid; and subjecting said solid to foaming conditions thereby to obtain the porous composite material.
Claim 2
Dependent Claim
82 words
A process for the production of a porous composite material, comprising the steps of: emulsifying an aqueous solution containing a hydrophilic polymer and a foaming agent into a solution of a hydrophobic polymer in an organic solvent to form an emulsion in which liquid particles of said aqueous solution are dispersed in said organic solution; removing said organic solvent and water from said emulsion to obtain a solid; and subjecting said solid to foaming conditions thereby to obtain the porous composite material.
Claim 3
Dependent Claim
79 words
A process as set forth in claim 1, wherein said emulsion forming step includes mixing the aqueous solution containing 1 to 20 wt % of the hydrophilic polymer and at least 5 wt % but up to the saturated concentration of the foaming agent with the organic solution containing 1 to 30 wt % of the hydrophobic polymer with a mixing ratio by weight of the former solution to the latter solution in the range of 2 to 20:100.
Claim 4
Dependent Claim
60 words
A process as set forth in claim 1 or 2, wherein the hydrophilic polymer is used in an amount of 1 to 25 parts by weight per 100 parts by weight of the hydrophobic polymer and the foaming agent is used in an amount of 2 to 70 parts by weight per 100 parts by weight of the hydrophobic polymer.
Claim 5
Dependent Claim
31 words
A process as set forth in claim 1, wherein the hydrophobic polymer is a resin selected from the group consisting of polyolefin resins, styrene resins, acrylic resins and polyvinyl chloride resins.
Claim 6
Dependent Claim
39 words
A process as set forth in claim 4, wherein the hydrophobic polymer is a member selected from the group consisting of polyethylene, polypropylene, polybutene, ethylene-prolylene copolymers, polystyrene, acrylonitrile-butadiene-styrene copolymers, polyacrylonitrile, a polyacrylic acid ester, polyvinyl chloride and polyvinylidene chloride.
Claim 7
Dependent Claim
35 words
A process as set forth in claim 1, wherein the hydrophilic polymer is a member selected from the group consisting of polyvinyl alcohol, polyacrylic acid, polyvinyl pyrrolidone, polyethylene glycol and a salt of polyacrylic acid.
Claim 8
Dependent Claim
31 words
A process as set forth in claim 1, wherein the foaming agent is a member selected from the group consisting of potassium bicarbonate, sodium bicarbonate, azodicarboamide, diphenylsulfone-3,3'-disulfohydrazine and benzenesulfonic acid diphenylhydrazine.
References Cited (Backward Citations)
US3027336A
Cited
US3816170A
Cited
US3879493A
Cited
US3795720A
Cited
US3873476A
Cited
US3888766A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |