# US 10,478,537 B2 · Cell separation filter material and filter obtained by layering same

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- Number: US 10,478,537 B2
- Document ID: US10478537B2
- Status: Granted
- Kind: B2
- Application number: 15/030,130
- Filed: 2014-10-07
- Published: 2016-09-15
- Granted: 2019-11-19
- Earliest claimed: 2013-10-18
- Assignees: Kaneka Corporation
- Applicants: Kaneka Corporation
- Inventors: Ikuhiro Suzuki; Takayuki Miyamoto; Takao Shibata
- Web page: https://patentgrep.com/patent/US10478537B2

## CPC

- A61M 1/3633: {Blood component filters, e.g. leukocyte filters}
- A61M 1/0218: {with filters}
- A61M 1/3496: {Plasmapheresis; Leucopheresis; Lymphopheresis (A61M1/3472 takes precedence)}
- A61M 1/3635: {Constructional details}
- A61M 1/3672: {Means preventing coagulation}
- A61M 1/38: Removing constituents from donor blood and {storing or} returning remainder to body {, e.g. for transfusion}
- B01D 39/1623: {of synthetic origin}
- A61M 2202/0014: removed from the body
- A61M 2202/0028: fluid entering a filter
- A61M 2205/75: with filters
- A61M 2205/7527: liquophilic, hydrophilic
- B01D 2239/1216: Pore size
- B01D 2239/1233: Fibre diameter
- B01D 2239/1291: Other parameters
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

An object of the present invention is to provide a novel filter material and a filter including the same. Specifically, the present invention aims to provide a filter material capable of filtering in a short period of time, without clogging of the filter, while maintaining high cell separation properties, and a filter including the same. More specifically, the present invention aims to provide a filter material in which fiber masses (flocs) are uniformly distributed, and a filter including the same. The present invention provides a novel filter material showing excellent cell separation properties and excellent flow-through properties regardless of design choices for filters known prior to the filing of the present application, and an efficient cell separation method using a novel filter on which the filter material is stacked.

## Claims

### Claim 1

A filter comprising:
an inlet and an outlet for a liquid; and
at least two nonwoven fabrics stacked in a liquid flow direction,
wherein
a nonwoven fabric, of the at least two nonwoven fabrics, on an inlet side of the filter, and a nonwoven fabric, of the at least two nonwoven fabrics, on an outlet side of the filter have an average fiber diameter of from 0.3 to 5.0 μm,
a thickness of from 0.10 to 0.60 mm,
a basis weight of from 10 to 100 g/m2, and
an average floc size index of from 1.0 to 4.0.

### Claim 2 (depends on 1)

The filter according to claim 1, wherein the nonwoven fabric on an outlet side of the filter has a floc size index ratio of from 0.78 to 1.02.

### Claim 3 (depends on 1)

The filter according to claim 1, wherein the nonwoven fabric on an outlet side of the filter has an average floc size index corresponding to that determined for a thickness of from 0.30 mm of 1.0 to 3.0.

### Claim 4 (depends on 1)

The filter according to claim 1, wherein the nonwoven fabric on an outlet side of the filter has a floc size index ratio of from 0.84 to 1.02 that corresponds to an average floc size index determined for a thickness of 0.30 mm.

### Claim 5 (depends on 1)

The filter according to claim 1, further comprising:
a different type of a filter material which is different from the at least two nonwoven fabrics, wherein the different type of a filter material is positioned on an inlet side, an outlet side, or both, of the filter.

### Claim 6 (depends on 1)

The filter according to claim 1, wherein
the filter comprises a first filter material positioned on an outlet side of the filter and a second filter material positioned on an inlet side of the filter, and
an average fiber diameter of the second filter material is larger than an average fiber diameter of the first filter material.

### Claim 7 (depends on 1)

The filter according to claim 1, further comprising:
a pre-filter material configured to remove microscopic aggregates and positioned on an inlet side of the filter.

### Claim 8 (depends on 1)

A filter system, comprising:
the filter according to claim 1;
a blood collection bag connected to an inlet side of the filter; and
at least one blood bag connected to an outlet side of the filter.

### Claim 9 (depends on 1)

The filter according to claim 1, wherein the filter comprises from 5 to 100 filter materials.

### Claim 10 (depends on 6)

The filter according to claim 6, wherein the average fiber diameter of the first filter material is from 0.3 to 5.0 μm, and the average fiber diameter of the second filter material is from 1.0 to 10.0 μm.

### Claim 11 (depends on 1)

The filter material according to claim 1, wherein the nonwoven fabric on an outlet side of the filter has the average fiber diameter of from 0.4 to 4.0 μm, the thickness of from 0.14 to 0.55 mm, and the average floc size index of from 2.3 to 3.4.

### Claim 12 (depends on 1)

The filter material according to claim 1, wherein at least one of the nonwoven fabrics has an average pore size of from 4.0 μm to 30.0 μm.