EP0180987A2
Expired / Lapsed
EP
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Flat permeable membrane and method for manufacture thereof
Assignee: Terumo Corp
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Filing: 1985-11-07
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Granted: —
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Expires: 2005-11-07
Abstract
Abstract A flat permeable membrane of polyolefin 10 to 5001 µm in thickness, which membrane has compact layers of intimately bound fine particles of polyolefin formed one each in the opposite surface regions of the membrane and a layer of an aggregate of fine discrete particles of an average diameter of 0.01 to 5 µm formed between the compact layers and, consequently, has fine through pores labyrinthically extended in the direction of thickness of the membrane to establish communication between the opposite surfaces of the membrane and a method for the manufacture of the permeable membrane.
Inventors
- 👤 Yukio Seita
- 👤 Makoto Emi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 12:42
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/003; B01D69/00; B01D69/02; B01D69/06; B01D71/00; B01D71/06; B01D71/26; B01D71/261; B01D71/262; B01D2323/00; B01D2323/15; B01D2323/21; B01D2325/00; B01D2325/02; B01D2325/022; B01D2325/023; C08J2201/00; C08J2201/04; C08J2201/054; C08J2201/0542; C08J2201/0543; C08J2201/0545; C08J2201/0546; C08J2323/00; C08J2323/02
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
86 words
A flat permeable membrane of polyolefin 10 to 500 um in thickness, which permeable membrane has compact layers of intimately bound fine particles of polyolefin formed on each in the opposite surface regions of said membrane and a layer of an aggregate of fine discrete particles of an average diameter of 0.01 to 5 µm formed between said compact layers and, consequently, has fine through pores labyrinthically extended in the direction of thickness of said membrane to establish communication between the opposite surfaces of said membrane.
Claim 2
Dependent Claim
86 words
A flat permeable membrane of polyolefin 10 to 500 um in thickness, which permeable membrane has compact layers of intimately bound fine particles of polyolefin formed on each in the opposite surface regions of said membrane and a layer of an aggregate of fine discrete particles of an average diameter of 0.01 to 5 µm formed between said compact layers and, consequently, has fine through pores labyrinthically extended in the direction of thickness of said membrane to establish communication between the opposite surfaces of said membrane.
Claim 3
Dependent Claim
30 words
A flat permeable membrane according to Claim 1, wherein the combined thickness of said two compact layers accounts for not more than 30% of the entire thickness of said membrane.
Claim 4
Dependent Claim
23 words
A flat permeable membrane according to Claim 1, wherein the porcsity of said polyolefin membrane is in the range of 10 to 60%.
Claim 5
Dependent Claim
28 words
A flat permeable membrane according to Claim 1, wherein said fine pores in said compact layers have an average diameter in the range of 0.01 to 5 um.
Claim 6
Dependent Claim
34 words
A flat permeable membrane according to Claim 1, wherein said fine particles of said layer of an aggregate of fine discrete particles have an average diameter in the range of 0.02 to 1.0 µm.
Claim 7
Dependent Claim
27 words
A flat permeable membrane according to Claim 1, wherein said polyolefin is at least one member selected from the group consisting of polyethylene, polypropylene, and ethylene-propylene copolymer.
Claim 8
Independent Claim
93 words
A method for the manufacture of a flat permeable membrane, which comprises mixing a polyolefin, a crystal seed forming agent, and an organic filler uniformly dispersible in said polyolefin in a molten state and easily soluble in an extractant to be used, discharging the resultant mixture in a molten state through a die, cooling and solidifying the discharged molten membrane by contact thereof with a cooling fluid, and placing the resultant cooled and solidified flat membrane into contact with an extractant incapable of dissolving said polyolefin thereby removing said organic filler by extraction.
Claim 9
Independent Claim
93 words
A method for the manufacture of a flat permeable membrane, which comprises mixing a polyolefin, a crystal seed forming agent, and an organic filler uniformly dispersible in said polyolefin in a molten state and easily soluble in an extractant to be used, discharging the resultant mixture in a molten state through a die, cooling and solidifying the discharged molten membrane by contact thereof with a cooling fluid, and placing the resultant cooled and solidified flat membrane into contact with an extractant incapable of dissolving said polyolefin thereby removing said organic filler by extraction.
Claim 10
Dependent Claim
26 words
A method according to Claim 7, wherein said organic filler is a hydrocarbon having a boiling point not less than the melting point of said polyolefin.
Claim 11
Dependent Claim
14 words
A method according to Claim 8, wherein said hydrocarbon is liquid paraffin orα-o1efin oligomer.
Claim 12
Dependent Claim
36 words
A method according to Claim 7, wherein the amount of said organic filler to be used is in the range of 35 to 300 parts by weight based on 100 parts by weight of said polyolefin.
Claim 13
Dependent Claim
25 words
A method according to Claim 7, wherein said polyolefin is at least one member selected from the group consisting of polyethylene, polypropylene, and ethylene-propylene copolymer.
Claim 14
Dependent Claim
42 words
A method according to Claim 7, wherein said crystal seed forming agent is an organic heat-resisting substance having a melting point of not less than 150°C and a gel point not less than the temperature at which said polyolefin begins to crystallize.
Claim 15
Dependent Claim
38 words
A method according to Claim 7, wherein the amount of said crystal seed forming agent to be used is in the range of 0.1 to 5 parts by weight based on 100 parts by weight of said polyolefin.
Claim 16
Dependent Claim
24 words
A method according to Claim 7, wherein said extractant is at least one member selected from the group consisting of alcohols and halogenated hydrocarbons.
Claim 17
Dependent Claim
13 words
A method according to Claim 7, wherein said cooling fluid is a liquid.
Claim 18
Dependent Claim
13 words
A method according to Claim 15, wherein said liquid is a non-extracting liquid.
Claim 19
Dependent Claim
14 words
A method according to Claim 7, wherein said cooling fluid is an inert gas.
Claim 20
Dependent Claim
12 words
A method according to Claim 17, wherein said inert gas is air.
Claim 21
Dependent Claim
18 words
A method according to Claim 7, wherein the temperature for cooling and solidifying is not more than 120°C.
Claim 22
Dependent Claim
12 words
A method according to Claim 16, wherein said non-extracting liquid in water.
References Cited (Backward Citations)
No citation records indexed.
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