Note: Descriptions are shown in the official language in which they were submitted.
CA 02424191 2003-04-O1
1 BACKGROUND OF THE INVENTION:
2 This invention relates to a new and improved foam for animal
3 care such as bovine teat dips and teat washes, and the like.
4 Another object of this invention is to provide a new and
improved combined foam teat dip and teat wash. Specifically, it
6 would be highly desirable to provide a foamed bovine teat dip which
7 would cover the outer teat area, and provide protection to the teat
8 canal when the teat sphincter is open following a milking
9 procedure, when the teat canal is exposed and highly vulnerable to
immediate infection. Even when the teat sphincter has closed, it
11 would still be desirable to prevent infection from reaching the
12 area of the teat opening, and the teat area in general with reduced
13 run off . This would enable the foam to adhere to and remain in
14 close and protective contact with the teat. Further, it is desired
to provide an apparatus with the capability of producing foam using
16 a wide variety of surfactants, such as those disclosed, supra.
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CA 02424191 2003-04-O1
1 U. S. Patents 3, 713, 423 and 4, 305, 346 describe an apparatus
2 which coats a bovine teat area with f ine spray or mist , but . these
3 patented devices are hand operated and do not produce any foam,
4 let alone a foam fulfilling the above protective characteristics .
It will also be appreciated that use of foam reduces the amount
6 of liquid used for a bovine teat dip compared to either a spray
7 or liquid dip, and hence an improvement in the, operation of these
8 two patents would be desirable.
9
THE INVENTION:
11 According to the invention, there is provided a method for
12 producing a combined foam teat dip and teat wash by pressurizing
13 air with surfactant at a relatively high pressure followed by
14 depressurization of the surfactant at atmospheric pressure to
produce a foam which penetrates adherent dirt which can then be
16 readily removed by. cloths typically used by. dairymen.
17
18 IN THE DRAWINGS:
19 FIGS. 1 and 2 are photomicrographs showing the foam products
of this invention at low and high magnifications; and,
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22 FIGS. 3 and 4 axe photomicrographs showing the foam products
23 of a commercial bovine foam teat dip at a low magnification.
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CA 02424191 2003-04-O1
1 The method for producing a foam, and the foam product
2 therefrom for a combined post teat dip and pre milking teat wash
3 comprises pressurizing a surfactant in a container with air,
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4 feeding the compressed air and surfactant to a flow or line mixer
under turbulent flow conditions.., and expanding the mixture of air
6 and surfactant from an initial pressurized value, in the flow or
7 line mixer through an open orifice and down to atmospheric
8 pressure into a container cup surrounding the teat and adjacent
9 udder area. A new and improved surfactant foam, or a mixture of
surfactant and biocide is formed thereby which adheres to the
11 teat, with reduced run off. Suitable types of equipment which
12 may be employed to provide the method and foam product of this
13 invention are disclosed in U.S. Patent 6, 302, 058 and, U.S. Serial
14 No.: 09/976,745 filed October 13, 2001, Docket: 1962-A,
incorporated herein by reference.
16
17 The foam of this invention is produced with a surfactant
18 alone, or a mixture of surfactant and germicide, bactericide,
19 and sufficient water, and pressuring the mixture with air {~02,
nitrogen, propellant, etc.) to produce a lubricating, penetrating
21 foam which may be used directly as a teat or udder wash, without
22 pre-wetting, and following application the foam may be removed by
23 wiping with a cloth.
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CA 02424191 2003-04-O1
1 If desired, in a larger use or industrial setting,
2 particularly when used to produce a combined foam teat dip and
3 teat wash, the container may be of larger size, and air is
s
4 combined with the surfactant, or surfactant and mixture of
germicide,'etc., by pressure c~ntrolled air pumps. One type of
6 equipment which may be modified to produce the desired type of
7 foam is described in U.S. Patents 3,713,423 and 4,304,346. The
8 equipment described in these two patents employ a flow and mixing
9 line for air and surfactant which is connected to the bottom
entry of a teat cup, and a spray nozzle ir~ounted at the entry.
11 This equipment may be modified by removing the spray nozzle,
12 thereby forming an open orifice in the teat cup. This
13 modification enables a mixture of surfactant and air to be
14 pressurized in the flow and mixing line. Upon depressurization
to atmospheric at the open orifice, the desired quality of
16 combined foam teat dip and teat wash is produced. This foam may
17 then be used as an initial teat dip and a subsequent post dip.
18 Typical flow and mixing line pressures vary from about:20 - 100
19 psi . , and typical flow and mixing line lengths useful in milking
operations are up to about 30 feet, and typically 20 - 30 feet.
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CA 02424191 2003-04-O1
1 The foam produced by the method of this invention is unique
2 in terms of functioning as a combined bovine teat dip and after-
3 milking teat wash since it adheres to the teat and udder area
4 without significant run off, and forms a bead at the end of the
teat. This area of the teat is~at signs.ficant risk of infection
6 both prior to and subsequent to milking, and the presence of the
7 bead considerably reduces the possibility of infection. Also,
8 since there is little foam run off , a longer period of protection
9 is afforded against bacterial infection. Moreover, following
cessation of milking, use of a post-dip which is not wiped off,
11 enables fresh available liquid and foam to cover the teat end for
12 about 8 - 12 minutes. This foam consistency provides sufficient
13 time for the open teat end and teat canal to be covered by a foam
14 bead when the teat sphincter is both open and closed, and hence
when the teat canal is at a high risk of infection.
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17 The foam produced by the method of this invention is shown
18 in FIGS. 1 and 2 were digitally photographed with a close focus,
19 high resolution Nikon digital camera and a long focus microscope
attached to a computer that captured the images in digital mode.
21 The microscopic images were captured by taking a thin slice. of
22 foam and back lighting with a high intensity light to overcome
23 the opacity of iodine germicide used in the teat dip which was
24 contained in the foam. The surfactant used in these photographs
is described in Applicant's patents, infra.
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CA 02424191 2003-04-O1
1 The micron size of the spherically formed bubbles was
2 determined by taking an image of a fifty micron wire at the same
3 focus as the bubble images and transferring this measured size
4 distance to the _ photomicrographs, shown by the f iducial marking .
Since it was not feasible to phbtograph the foam as it was being
6 formed, the images were made with delay from 45 seconds to
7 several minutes.
8
9 The size of the newly formed foam bubbles was measured and
photographed as between 5 - 200 microns in diameter, and
11 preferably below 200 microns in diameter, the bulk of the bubbles
12 being close to about 50 microns in size. While some of the
13 bubbles (about 15%) in these photographs are greater than 200
14 microns, they were either formed by an imbalance of air with the
liquid flow, or formed by the bubbles joining together over time.
16 The bubbles contained in the liquid matrix are at a higher
17 pressure than atmospheric, and the foam .is characterized as being
18 a liquid with spherical air bubble inclusions, without walls, a
19 wall being defined as having inner and outer surfaces. The foam
itself is best described as being "stiff".
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CA 02424191 2003-04-O1
1 Pressure exceeding atmospheric within the bubbles was
2 calculated using the surface tension of the iodine teat dip which
3 was used when obtaining the microphotographs, the pressure
4 becoming greater as the bubble diameter decreases. This pressure
can be calculated by the formula: P (inside bubble) - P(outside
6 bubble) + 2 x (surface tension) /bubble radius, and is measured at
7 a solution surface tension of 32 dynes/cm. (~'he surface tension
8 of pure water is 70 dynes/cm.).
9
Hence, the pressure difference across the bubble is
11 therefore inversely proportional to the bubble size.
12 Accordingly, the pressure inside a 15 micron bubble is 2.4 psi
13 above ambient pressure (14.6 psi) and a visual observation of a
14 5 micron bubble size would calculate to wn internal pressure of
about 7.2 pounds higher than atmospheric. Since the maximum
16 resolution of the long focus microscope is 4~ microns, if bubbles
17 of 1 micron were formed at the actual time of foam generation,
18 they would have internal pressures of about 36 psi over
19 atmospheric, and this would obviously account for the stiffness
and persistence of the foam.
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CA 02424191 2003-04-O1
1 By contrast, bubbles produced by equipment described in U. S .
2 Patent 5,722,350 (i.e., FIGS. 3 and 4) produced bubbles having a
3 size range of about 600 - 1200 microns. The differential
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4 internal bubble pressure of about 2.4/40 - 0.06 psi, is low
enough that result in the bubbles sharing common walls and appear
6 to be hexagonally-shaped, rather than the much smaller, spherical
7 bubbles produced by this invention. This wo~zld account for the
8 "loose" type of relatively short lasting foam produced by the
9 equipment of that patent.
11 In addition to those surfactants described in MeCutcheon's
12 publications, surfactants which may be useful in the foams of
13 this invention are described in U"S. Patents 2,977,315;
14 3,950,544; 4,049,830; 4,258,056; 4,371,517; 4,671,958; 4,678,668;
4,940,702; 5,028,427; 5,175,160; 5,208,257; 5,466,959 (PVP);
16 5,529,770 (C16-ie fatty alcohols); 5,616,348 (polyethoxylated
17 polyoxypropylene block copolymer - POLO~AMER); and German Patent
18 2,936,934, incorporated herein by reference. Also useful
19 surfactants are 9 - 12 mole ethoxylated alkyl phenols; nonyl
phenoxy polyethoxy ethanol surfactant; and, non-ionic fatty
21 alcohol polyglycol ether carboxylic acid.
22
23 Surfactants such as polyethenoxy detergents and IZ are
24 disclosed in an article by Benjamin Carroll in the Journal of
Bacteriology, 69: 413-417, (1955) are useful as foams.
9
CA 02424191 2003-04-O1
1 Commercial surfactants containing iodine which are known for
2 use as teat dip formulations include 9 - 12 mole ethoxylated
3 phenols. A surfactant of this type is sold by Norman Fox & Co.
4 under the trade name of NORFOX N-P9, and listed in "McCutcheon' s
Emulsifiers and Detergents", (1989 and 1994) specifically for use
6 with iodophors. Another type of teat dip is sold by KlenzadeT"'
7 Teat Guard, and contains a nonyl phenoxypolyethoxy ethanol
8 surfactant having 1% titratable iodine. Both of these
9 surfactants may also be used in the foam produc t of this
invention, provided they comply with existing regulations.
11 However, producers, distributors and users of nonyl phenoxy
12 surfactants should be continually aware of ongoing regulations
13 governing the use of specific surfactants in this category when
14 used for bovine teat dips due to possible mutagenic effects of a
given surfactant.
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17 Applicant's U.S. Patents 5,720,984 and 5,534,266 describe a
18 non-ionic, fatty alcohol polyglycol ether carboxylic acid and
19 sold under the trade names of AKYPOT"'RLM-45, AKYPOTMRLM-1a0,
AKYPOT"'RLM-160, and mixtures thereof, the preferred composition
21 being AKYPOT'"RLM-100 (Chemical Abstracts Registry 74349-89-6).
22 As noted in these Applicant's patents, supra, the herd life of
23 cows varies from about 3 - 7 years, but there has been no
24 noticeable reduction in herd life in the approximate 2.5 years
since the product has been in use.
CA 02424191 2003-04-O1
1 Patents which relate either directly or indirectly to foam
2 or defoamers in connection with bovine teat dips are disclosed in
3 U.S. Patents 2,989,434; 4,945,110; 5,063,249; 5,370,815;
t
4 5,575,993; 5,722,350; 5,843,912; and, 5,967,202. European Patent
077,2973; and, French Patent 2,633,308 also describe bovine teat
6 dip foams.
7
8 Germicides or bactericides which may be employed in the'
9 foams of this invention include: chlorhexidine, I2, iodides such
as I-, HI, or equivalent (e. g., KI, NaI, CaIz, etc.), iodophors,
11 etc., chlorine dioxide, quaternary ammonium compounds, etc.
12
13 The amount of water employed in the foam compositions of
14 this invention is typically about 78% - 95% by weight, and this
enables a sufficient dilution of the germicide in the foam to
16 reduce the amount required and satisfy USDA and FDA requirements
17 for the content of sanitizers, due inter olio to the penetrating
18 capabilities of the foam.
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