Canadian Patents Database / Patent 1129498 Summary

Third-party information liability

Some of the information on this Web page has been provided by external sources. The Government of Canada is not responsible for the accuracy, reliability or currency of the information supplied by external sources. Users wishing to rely upon this information should consult directly with the source of the information. Content provided by external sources is not subject to official languages, privacy and accessibility requirements.

Claims and Abstract availability

Any discrepancies in the text and image of the Claims and Abstract are due to differing posting times. Text of the Claims and Abstract are posted:

  • At the time the application is open to public inspection;
  • At the time of issue of the patent (grant).
(12) Patent: (11) CA 1129498
(21) Application Number: 338319
(54) English Title: STRUCTURAL CONFIGURATION AND METHOD FOR TRANSPORT OF A LIQUID DROP THROUGH AN INGRESS APERTURE
(54) French Title: CONSTRUCTION POUR LE TRANSPORT D'UNE GOUTTE VERS UN ORIFICE D'ADMISSION, ET METHODE CONNEXE
(52) Canadian Patent Classification (CPC):
  • 324/23
(51) International Patent Classification (IPC):
  • G01N 27/00 (2006.01)
  • B01L 3/00 (2006.01)
(72) Inventors :
  • COLUMBUS, RICHARD L. (United States of America)
(73) Owners :
  • EASTMAN KODAK COMPANY (United States of America)
(71) Applicants :
(74) Agent: GOWLING LAFLEUR HENDERSON LLP
(74) Associate agent: GOWLING LAFLEUR HENDERSON LLP
(45) Issued: 1982-08-10
(22) Filed Date: 1979-10-24
(30) Availability of licence: N/A
(30) Language of filing: English

(30) Application Priority Data:
Application No. Country/Territory Date
59,924 United States of America 1979-07-23
954,689 United States of America 1978-10-25

English Abstract


-1-
IMPROVED STRUCTURAL CONFIGURATION AND METHOD FOR TRANSPORT
OF A LIQUID DROP THROUGH AN INGRESS APERTURE
Abstract
A device is disclosed that includes an ingress
aperture which provides improved transport of a drop of
liquid, from an exterior surface of the device to the device
interior. Means, such as a corner, are provided at the inter-
section of the aperture sidewall and the exterior surface for
urging a drop deposited thereon to move into contact with the
aperture sidewall and thus into the aperture.


Note: Claims are shown in the official language in which they were submitted.

-11-
What is claimed is:
1. In a liquid transport device comprising an
exterior, drop-receiving surface, means interior of said
surface for transporting the liquid through a zone, and an
ingress aperture comprising an internal sidewall fluidly
connecting said surface and said interior transporting means,
the improvement wherein at least the intersection
of said exterior surface and said sidewall includes at a pre-
determined location, means for substantially urging a por-
tion of a drop of liquid deposited thereon to move into
contact with said sidewall.
2. A device as defined in claim 1, wherein said
urging means comprises a surface configuration capable of
forming a compound meniscus on a contacting liquid drop.
3. A device as defined in claim 1 or 2, wherein
said predetermined location comprises an interior corner in
the aperture sidewall at at least said exterior surface.
4. A device as defined in claim 1, wherein said
intersection includes from 3 to about 10 of said urging
means at spaced-apart locations.
5. A device as defined in claim 1, wherein said
aperture has six of said urging means.
6. A device as defined in claim 1, wherein said
aperture, at said intersection, has a transverse cross-
sectional shape of a regular hexagon.
7. A device as defined in claim 1, wherein said
transporting means includes two spaced-apart opposed sur-
faces at least one of which includes an absorbent layer
containing at least one reagent capable of producing a
radiometrically detectable signal when contacted by the
liquid of the drop.
8. In a liquid transport device comprising an
exterior, drop-receiving surface, a capillary transport zone
interior of said surface formed by interior, capillary-
spaced surfaces of first and second wall members, one of
said wall members including a liquid ingress aperture com-
prising a sidewall extending from said exterior surface to
said transport zone,

-12-
the improvement wherein at least the intersection
of said exterior surface and said sidewall includes at a
predetermined location, means for substantially urging a
drop of liquid deposited on said surface to move into con-
tact with said sidewall.
9. A device as defined in claim 8, wherein said
predetermined location comprises an interior corner in the
aperture sidewall at at least said exterior surface.
10. A device as defined in claim 8, wherein said
intersection includes said urging means at a plurality Or
predetermined, spaced-apart locations numbering from 3 to
about 10.
11. A device as defined in claim 8, wherein said
intersection includes said urging means at six generally
equidistantly spaced locations.
12. A device as defined in claim 8, wherein said
aperture has a transverse cross-sectional shape of a regular
hexagon.
13. A device as defined in claim 8, wherein one of
said interior surfaces includes an absorbent layer con-
taining at least one reagent capable of producing a radio-
metrically detectable signal when contacted by the liquid of
the drop.
14. In a liquid transport device comprising an
exterior, drop-receiving surface, a capillary transport zone
interior of said surface formed by interior, capillary-
spaced surfaces of first and second members, one of said
members including an ingress aperture extending from said
exterior surface to said transport zone,
the improvement wherein said aperture comprises
from 3 to about 10 distinct sidewalls extending between said
exterior surface and said interior surface of said one
member, and intersecting to define from 3 to about 10
interior corners.
15. A device as defined in claim 14, wherein said
aperture has six corners defined by six intersecting side-
walls.
16. A device as defined in claim 14, wherein said

-13-
aperture has a transverse cross-sectional shape of a regular
hexagon.
17. A device as defined in claim 14, wherein said
other member interior surface is the exposed surface of an
absorbent layer containing at least one reagent capable of
producing a radiometrically detectable signal when contacted
by the liquid.
18. A test device for radiometric detection of an
analyte of a liquid, comprising
a support,
a cover member spaced away from the support,
one or more layers disposed sequentially on the
support and containing at least one reagent composition in
at least one of said layers, said composition being capable
of producing a radiometrically detectable signal that is
proportional to the quantity of the analyte,
means for sealing said layers between said support
and said cover member with a capillary space between the
outermost one of said layers and said cover member, said space
being effective to provide capillary flow of liquid between
said cover member and said outermost layer,
said cover member including a liquid ingress
aperture and an air vent aperture spaced away from said
access aperture,
said ingress aperture having a sidewall extending
through said cover member and comprising six surfaces inter-
secting to form six corners,
whereby a drop of the liquid placed in contact
with said cover member at said ingress aperture is urged by
said corners to enter the aperture and said capillary space.
19. A method of transporting a drop of liquid
through an aperture in a wall member from an exterior surface
to an interior surface of that member, said aperture being
defined by a sidewall that includes, at a predetermined loca-
tion at least at the intersection of said exterior surface and
the sidewall, means for urging a drop of deposited liquid
to move into contact with the sidewall, the method comprising
the steps of:


-14-
a) placing said wall member in a drop-displacing
zone adjacent to a source of drops of the liquid, and
b) applying a drop to said aperture in operative
contact with said urging means,
whereby the drop fills the aperture and transport
is assured.

Note: Descriptions are shown in the official language in which they were submitted.

~z~

IMPROVE3 STRUC~URAL CONFIGURATION AND METHOD FOR TRANSPORT
OF A LIQ~ID DROP THRO~GH AN INGRESS APERTURE
Background of the Invention
1) Field of the Invention
This invention is dlrected to a device and method
for transport of a llquid drop through an ingress aperture,
e.g., into a transport zone prior to processing of the
liquid. In a prererred embodiment, such aperture cooperates
with opposed surfaces located within the device whlch provide
for capillary flow of liquid within a transport zone. One of
the surfaces can include a reagent-containing layer suitable
for a radiometric analysis of the liquid.
2) State of the Prior Art
A number of liquid transport devices rely upon
capillary flow Or liquid between two spaced-apart surfaces
to spread the liquid. For example, an enclosed capillary
chamber can be provided by sealing a cover sheet, e.g.,
around its perimeter to a reagent layer laminated to a
support so that the cover sheet ls left spaced away from the
20reagent layer a distance suitable for capillary flow. At
least two apertures are then provided in the chamber. One
aperture provides for the introduction Or drops or liquid,
and the other for the venting of air as the capillary cham-
ber is filled. Such a device is shown, e.g., in U.S. Patent
25N- 3,690,836, issued on September 12, 1972.
Prior to this invention, the lngress aperture for
introduction Or liquid lnto a devlce Or the type described
above has featured a smooth, curved sidewall, such as a
cyllndrical wall. Such apertures sufrer the disadvantage
30that a drop of liquid that is not accurately placed on the
cover sheet, i.e., is placed wlth its center outside
the sidewall Or the aperture, tends to stay outside the
aperture rather than move into it. It is only when the
center Or the drop ls deposlted well wlthin the aperture
35 that the surface tension of the llquld drop forces the drop
into the aperture in full contact with the sidewall. Parti-
cularly this has been a problem ror cover sheets formed from
materials that tend to be hydrophoblc, i.e., that form with

4~

the liquid in question a liquid-vapor contact angle that is
greater than 90. For example, certain plastlcs are suf-
ficiently hydrophobic that drops of liquid such as blood
serum are more likely to remain on the cover sheet than to
5 flow into a cylindrical aperture in the sheet.
3) Related Applications
-
Canadian Application Serial No. 338,320, filed on
October 24, 1979, entitled "Electrode-Containing Device with
Capillary Transport Between Electrodes" discloses liquid trans-
port devices that function as a bridge between two electrodes,
the liquid access apertures in one embodiment being a hexagon.
U.S. Patent No. 4,233,029, issued November 11, 1980, entitled
"Liquid Transport Device and Method", discloses such a hexagonal
aperture for use in a llquid transport device in general.
S~MMARY OF THE INVENTION
This invention concerns the discovery that the
ingress aperture of such devices ca~ be predeterminedly
shaped to be more effective in urging applied drops into lt
20 than previous apertures of the type having a sidewall com-
prising a smooth, curved surface, e.g., a cylinder.
More specifically, there is provided an lmproved
liquid transport device comprising an exterior, drop-receiving
surface, means interior of said surface for transporting the
25 liquid through a zone, and an ingress aperture comprising an
internal sidewall fluidly connecting the surface and the
interior transporting means. The improvement features, in at
].east the intersection of the exterior surface and the
sidewall, at a predetermined location, means for substantlally
3 urging a portion of a drop of liquid deposited on the sur-
face to move lnto contact wlth the sldewall.
Such a device is particularly useful in intro-
ducing liquid into a transport zone between two opposed
transport surfaces spaced apart a distance effective to
35 induce capillary flow of the liquid between the transport
surfaces.
Thus, in accordance with the present inventlon,
there is provided a device having a drop-centering aperture

~z~
--3--
for the improved conveyance of a drop of llquid from an
exterior surface to an interior liquid transport zone of
the device.
It is a significant aspect of the inventlon that
aperture geometry facilitates such drop-centerlng.
In yet another related aspect of the inventlon, a
test device for radiometric detection of an analyte ls
provided with a self-centering aperture.
Other features and advantages will become apparent
10 upon reference to the following Description of the Preferred
Embodiments when read ln llght of the attached drawlngs.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is an enlarged dimetric view of a device pre-
pared in accordance with the lnvention;
Fig. 2 is an elevational vlew in section through
the aperture of the cover sheet, demonstratlng the operation
Or the device;
Fig. 3 is a fragmentary, diagrammatic plan view
illustrating an effect of the invention;
Fig. 4 is a plan view Or a preferred embodiment of
the invention,^and
Fig. 5 is a sectional view taken generally along
the plane of line V-V of Fig. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device and method of this invention ls
described in connectlon wlth preferred embodlments featurlng
the capillary transport of biological liquids and particularly
blood serum, between two opposed surfaces. In addltion, the
devlce and rnethod can be applled to any llquld a drop of
3 whlch ls to be carrled through an lngress aperture from an
exterlor surface to a transport means for transportlng the
llquld for any end use. For example, lndustrlal liquids can
be so transported.
A device 10 constructed in accordance wlth one
35 embodiment of the invention comprises, Fig. 1, two members
12 and 14 each havlng an exterior surface 16 and lô, re-
spectlvely, and interlor, opposed surfaces 20 and 22, re-
spectively. Edge surfaces 24 define the limits of extenslon
.

of the members. Surfaces 20 and 22 are spaced apart a
distance "x", Fig. 2, that is effective to induce capillary
flow of liquid between the surfaces, as is described in the
aforesaid commonly-owned application and patent. In this manner
the spaced-apart surfaces 20 and 22 define a transport zone 26
and act as means for transporting introduced liquid between
the surfaces. As will be readily apparent, a range of
values for "x" is permissible, and the exact value depends
upon the liquid being transported.
Surfaces 20 and 22 can each be smooth, Figs. 1 and
2, or provided with a variety of surface configurations such
as parallel grooves, the grooves of one surface being
aligned or at a positive angle with respect to the grooves
of the other.
A preferred means for introducing a drop of liquid
into zone 26 is an aperture 30 extending from surface 16 to
surface 20, through member 12. The aperture comprises a
sidewall 32 extending between the surfaces. The preferred
largest flow-through dimension of aperture 30, measured as
an outside diameter, is one which is about equal to the
greatest diameter of the expected drop. The drop diameter
in turn is dictated by the volume and surface tension of the
drop. The volume of the drop should be adequate to fill
transport zone 26 to the extent desi.red. For uses such as
clinical analysis as herein described, a convenient drop
volume is about 10 ~1. Thus, slnce a 10 ~1 drop of fluld
having 70 dynes/cm surface tension has a diameter of about
0.26 cm, the largest flow-through dimension, measured as an
outside diameter, Fig. 1, is preferably about 0.26 cm.
3 In accordance with one aspect of the lnventlon,
the intersection of surface 16 and sldewall 32 ls provlded
with means that encourage the selected drop of liquid
deposited or received on surface 16 generally at aperture 30
to move into contact with the entire perlmeter of sldewall
32. More specifically, sidewall 32 is shaped so as to
comprise a plurality of surfaces that intersect, at least
with surface 16, at predetermined locations to form a
plurality of interior corners 34. As used herein, "prede-


~2~

termined location" or "locations" means locatlons dellber-
ately chosen, and distinguishes the clalmed lnventlon from
cylindrical apertures which lnadvertently or accldentally
have imperfections, such as microscopic corners, ln the
sidewall. Such accidental constructs are not capable of
providing substantial urging of the drop lnto the aperture.
As shown in Fig. 1, sidewall 32 comprises throughout lts
length, six sidewall surfaces and six such predetermlned
corners 34. Equal angles of such corners and equal wldths
of the intersecting surfaces are selected to provlde a
transverse, cross-sectlonal shape that ls a regular hexagon,
the preferred configuration.
In operation, Fig. 2, device 10 is placed in a drop-
displacing zone ad~acent to a source of drops, and a drop A
cf liquid such as blood serum or whole blood is dropped onto
the device as a free-form drop or is touched off from a
pendant surface, arrow 35, onto surface 16 generally at
aperture 30. The surface 16 preferably ls maintalned ln a
generally horizontal orientation during thls step. Corners
34 act to center the drop and urge lt into contact with the
surfaces of sidewall 32. It then moves down lnto zone 26
and into contact with surface 22, where capillary attraction
further causes the llquid to spread throughout zone 26,
arrows 36, to the posltion shown in phantom. Assumlng
sufflcient volume in the drop, the spreadlng ceases at edge
surfaces 24 which define an energy barrler to further cap-
lllary flow. Once the drop of llquld is so distrlbuted, a
varlety of processing can be done to the liquld, as wlll be
appreciated.
Thus the drop ls applied to aperture 30 so as
to contact one of the corners, to lnsure effectlve filllng
of the aperture. The effect is most pronounced when the center
of gravity of the drop is positioned over the aperture, rather
than the solid surface 16.
To vent air as the llquid advances within zone 26,
means are provided withln the devlce, such as the open space
between members 12 and 14 along all or a portion of any one
of edge surfaces 24. Alternatively, a second aperture, not

l~ Z~
--6--
shown, can be formed in either member 12 or 14.
The corners of the aperture, at the surface 16
where the drop is first applied, appear to act as centers of
force whlch induce the drop to move into contact with sidewall
32 along its entire perimeter or clrcumference. That ls, re-
ferring to Fig. 3, it ls believed that the centering force
F3 of a drop A applied at one of the corners 34 is signifl-
cantly greater than the corresponding centering force Fl or
F2 that exists for a drop A' placed at any adJacent location
38 or 39 spaced apart or away from a corner. At least one
corner is needed for the effect. However9 at least three
corners 34 are preferred, as in Flg. 3, to lnsure a greater
likelihood that the drop A will be in contact wlth a corner
34 when it contacts surface 16.
For a predetermlned largest flow-through dlmenslon
of the sidewall 32 calculated as described above, the greater
the number of corners that are created by the use of a
colresponding number of intersecting surfaces, then the
greater is the likellhood that the drop wlll contact a
corner. However, as the number of corners ls lncreased, so
is the value of the interior angle of each corner, untll
e~/entually the sidewall 32 approaches a smooth, curved
~urface in shape wherein all the centering forces are equal,
and the effect is lost. It has been found, therefore, that
a preferred number of corners ls between three and about
ten. Highly preferred ls slx corners ln a regular hexagon.
As a matter of practlcallty, the corners 34 wlll
have a slight radlus of curvature. For the corners to be
effectlve, they each should have a radius of curvature that
is no larger than about 0.4 mm.
Although flat or planar surfaces are preferred
between the corners, they can also be contlnuously curved as
shown, e.g., for surface 39, Flg. 3.
Although the centerlng mechanism of the corners ls
not fully understood, it ls belleved that the effect ls due
to forces that apply to the compound menlscus when the drop
ls located at a corner 34. As is well known, a compound
meniscus is one in which the princlpal radil of curvature of


--7--
the drop surface vary, depending on the locatlon taken on
the surface of the drop. If the drop is properly located at
a corner, the compound meniscus forms a drop that extends
laterally farther out over the aperture than lt does when not
located at a corner, and the weight of this extension causes
the drop to fall or otherwise move into contact with the
perimeter of sidewall 32 and then through the aperture. Or,
there is at the corner a greater tendency for the drop to
wet the sidewall than would occur in the absence of a cor-
ner.
It will be readily appreciated that the centeringforce of corners 34 is needed primarily at the lntersectlon
of sidewall 32 and exterlor surface 16. Thus, aperture 30
will function equally as well if sidewall 32 ls smoothed out
as it approaches surface 20 to form a cylinder, not shown.
In addition, it will also be appreciated that the
presence of a capillary zone below aperture 30, and speciri-
cally surface 22 that contacts a drop in aperture 30, assists
in metering the drop through aperture 30 and into the zone.
Members 12 and 14 can be formed from any suitable
material, such as plastic as shown, or from metal.
In ~igs. 4 and 5, a preferred form of the device
is one in which a transport chamber is formed for radio-
metric analysis of an analyte of a biologlcal llquid such as
blood. Parts similar to those previously described bear the
same reference numeral to which the distinguishing suffix
"a" is appended. Thus device 10a features a support member
14a, ~ig. 5, a cover member 12a, a spacer member 50 used to
adhere members 12a and 14a together, and a radiometrlcally
3 detectable test element 60 disposed on support 14a spaced
away from member 12a to define a transport zone 26a. The
spacing between surface 20a and the test element ls a cap-
illary spacing to lnduce the drop that enters through
aperture 30a to spread throughout the zone 26a. Preferably,
the test element 60 abuts agalnst the sldewalls of spacer
member 50, and is held against member 14a by means such as
adhesive.
Thus, the members 12a, 14a and 50 deflne a cap-


..2
--8--illary transport chamber contalning the test element 60 and
having any convenient shape, such as a rectangular chamber
when viewed in plan, Fig. 4.
Any sultable ~oining means can be applied between
members 12a and 50, and members 50 and 14a. For example, a
variety of adhesives can be used, or if all the members are
plastic, ultrasonic welding or heat-sealing can be used.
Member 12a is provided with an access aperture 30a
extending through the member from its exterior surface 16a
10 to zone 26a, disposed directly above a portlon of test
element 60. At least that portion of the aperture's slde-
wall 32a that lntersects with surface 16a is provlded wlth
corners 34a as described above. Preferably sldewall 32a ls
ln the cross-sectional shape of a regular hexagon. An
15 addltlonal, cyllndrlcally shaped aperture 70 in member 12a
acts as a vent for expelled air.
A viewing aperture or port 80 is optionally pro-
vided in support member 14a, partlcularly when the latter
member is not ltself transparent.
Test element 60 comprlses an optlonal transparent
support 62, such as poly(ethylene terephthalate), and at
least an absorbent layer 64 disposed on support 62. Such
layer can have a varlety of blnder composltlons, for
example, gelatin, cellulose acetate butyrate, polyvinyl
alcohol, agarose and the llke, the degree Or hydrophlllclty
of whlch depends upon the material selected. Gelatin ls
partlcuarly preferred as it acts as a wetting agent to pro-
vide for unlform llquld flow through zone 26a. Support 62
can be omitted where adequate support for layer 64 can be
3 obtained from support member 14a.
Addltional layers such as a layer 66 can be dls-
posed above layer 64 to provlde a varlety of chemlstries or
functlons, such as to provlde, either ln layer 66 alone or
together with layer 64, a reagent compositlon. Filterlng,
registration and mordanting functlons can be provided also
by such addltlonal layers, such as are described in U.S.
Patent No. 4,042,335, issued on August 16, 1977. Thus,
layer 66 can comprise a reagent, such as an enzyme, and a

2~4~3
g
binder Or the same type as is used for layer 64.
As used herein, "reagent" in "reagent composltion"
means a material that is capable of lnteractlon wlth an
analyte, a precursor of an analyte, a decomposltlon product
of an analyte, or an intermedlate. Thus, one of the re-
agents can be a preformed, radiometrically detectable specles
that is caused by the analyte of cholce to move out Or a
radiometrically opaque portlon or layer of the element, such
as layer 66, into a radiometrlcally transparent portlon or
layer, such as a reglstration layer.
The noted lnteractlon between the reagents of the
reagent composition and the analyte is therefore meant to
re~er to chemical reactlon, catalytlc actlvlty as ln the
formation o~ an enzyme-substrate complex, or any other form
of chemical or physlcal lnteractlon, lncludlng physlcal
dlsplacement, that can produce ultlmately a radiometrically
detectable slgnal in the element 60. As ls well known,
radiometric detection lncludes both colorlmetrlc and fluorl-
metric detectlon, dependlng upon the lndlcator reagent
selected for the assay. The assay Or the element ls de-
signed to produce a signal that ls proportlonal to the
amount of analyte that ls present.
A wide variety of radlometrlc assays can be pro-
vided by element 60. Preferably, the assays are all oxygen-
lndependent, as the flow of blood or blood serum into zone26a tends to seal off element 60 from any addltlonal oxygen.
Typical analytes whlch can be tested lnclude BUN, total
proteln, bilirubin and the like. The necessary reagents and
binder or vehlcle composltlons ror the layers of element 60,
3 such as layers 64 and 66, ~or these analytes can be those
descrlbed ln, respectlvely, U.S. Patent Nos. 4,o66,403,
issued on January 3, 1978; 4,132,528, lssued on January 2,
1979; and 4,069,016 or 4,069,017, issued on January 17, 1978;
and the llke.
Quantitatlve detectlon of the change produced in
element 60 by reason Or the analyte of the test element ls
preferably made by scannlng the element through port 80 with
a photometer or fluorimeter. A variety of such instruments

~ ~ Z ~ ~Q ~
--10--
can be used, for example the radlometer disclosed ln German
OLS 2,755,334, published June 29, 1978, or the photometer
descrlbed in ~.S. Patent No. 4,119,381, issued on October
10, 1978.
The following is an illustrative example Or the
device shown in Figs. 4 and 5.
Example
Members 12a and 14a are formed from polystyrene of
a thickness 0.127 and 0.254 mm, respectively, member 50
10 being steel of a thickness 0.38 mm. The three members are
sealed together by adhesives such as polybutyl acrylate
adhesive obtainable from Franklln Chemical under the trade-
mark "Covinax". Apertures 30a and 70 in member 12a are about
8 mm apart on center, the outside dlameter Or the hexagon of
15 aperture 30a belng about 2.6 mm. Vlew port 80 is about
5 mm ln diameter. The capillary spaclng between test element
60 and member 12a ls about 0.05 mm and the width Or element
60 ls about 11.5 mm.
For a test element 60 deslgned to detect total
protein, in a lO~ul drop Or blood serum, the following
sequential layers are used:
Layer Composition Amount
62 Gelatln-subbed 175 microns
poly(ethylene tere- thlck
phthalate)
oly(acrylamlde-co-N- 16-0 g/m2
~ vlnyl-2-pyrrolidone
64 ~ Cuso4-5H2o 10.8 g/m
~ LiOH 5.4 g/m
3 ~ tartarlc acid 8.0 g/m
The inventlon has been described ln detall wlth
particular reference to certain preferred embodlments thereor,
but it will be understood that varlatlons and modifications can
be effected within the spirit and scope Or the invention.


Sorry, the representative drawing for patent document number 1129498 was not found.

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Admin Status

Title Date
Forecasted Issue Date 1982-08-10
(22) Filed 1979-10-24
(45) Issued 1982-08-10
Expired 1999-08-10

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Filing $0.00 1979-10-24
Current owners on record shown in alphabetical order.
Current Owners on Record
EASTMAN KODAK COMPANY
Past owners on record shown in alphabetical order.
Past Owners on Record
None
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.

To view selected files, please enter reCAPTCHA code :




Filter Download Selected in PDF format (Zip Archive)
Document
Description
Date
(yyyy-mm-dd)
Number of pages Size of Image (KB)
Drawings 1994-02-22 2 39
Claims 1994-02-22 4 143
Abstract 1994-02-22 1 15
Cover Page 1994-02-22 1 13
Description 1994-02-22 10 476