Note: Descriptions are shown in the official language in which they were submitted.
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1
Field of the Invention
The invention relates generally to methods and compositions for cleaning
polyethylene terephthalate containers. More specifically, the invention
relates to
methods and compositions which remove mold., present on polyethylene
terephthalate
containers, with reduced hazing.
Backg~rou, nd of the Invention
As with many industries, the drive tow~~rds economy has also effected the
beverage industry and has resulted in certain real changes in the way in which
beverages
are bottled, distributed and dispensed. In the last decade-the beverage
industry has seen
a switch from glass to plastic containers. Plastiic containers may be made
from any
number of materials depending on the application. One material is polyethylene
terephthalate, "PET". Two types of PET bottles that are commonly used are
single trip
and mufti-trip bottles. Single trip bottles are those which are filled, used,
and then
discarded. Mufti-trip bottles are collected and reused and must be washed
before
refilling.
PET bottles offer several advantages over glass. Their light weight reduces
freight costs. When dropped onto a hard surface they do not shatter like glass
and
generally do not break. Conveyor wear caused by the containers in the
packaging plant
is also reduced. The closure is also generally reusable after a bottle has
been opened.
Disadvantages are that PET bottles are easily scratched, and susceptible to
chemical attack when they are washed. PET containers also do not tolerate
conditions
above 60°C. Exposing them to higher temperatures than 60°C
causes deformation
and/or shrinkage of the bottles.
Recycling of PET containers was recently approved by the FDA in the USA to
permit turning used containers into new ones. Because new resin costs 50 to 75
cents
per pound, recycling used bottles is economically attractive. In time, glass
soft drink
bottles are expected to disappear from the marl~;et. This heightens the
relevance of PET
container processing even further.
The cleaning of PET bottles takes place over a series of steps using caustic
immersion tanks and spray wash stages in a bottlewasher. In the wash tanks,
product
residue, dirt, labels and labeling adhesive are removed. Because the surface
of PET
bottles is hydrophobic, cleaning them is more difficult than glass bottles.
Also, the
lower washing temperature decreases the chemical activity of the bottlewashing
solution.
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Two principle problems in the cleaning of PET bottles are touched on by
Laufenberg et al., "Cleaning, Disinfecting, and Transporting Pet Returnables",
Brew
Bev. Ind. Int. 1, 40-4 (0 ref.) January, 1992.
In this article, the author outlines the susceptibility of the PET bottles to
corrosion or hazing. Hazing results from the chemical etching of the surface
of the PET
container by the caustic present in the wash bath.
An especially challenging problem which affects reusable PET bottles is the
occurrence of mold in returned bottles. To simply discard all bottles from
which mold
can not be removed is prohibitively expensive. Reject rates of 40 to 50% have
occurred
at certain times of the year in countries located in tropical climates.
The necessary cleaning temperature for PET bottles is 60°C or less due
to the
glass transition temperature of PET. If exceeded, PET bottles deform and
shrink. The
cleaning power of a bottlewashing solution at 60°C is only one quarter
that at 80°C.
Bottles returned with product residue, i.e., those bottles that have not been
rinsed, are
almost always contaminated with microbiological forms of life. The bottle
washing
solution eliminates the presence of microbiological forms of life such as
bacteria,
spores, molds, and yeasts present in the bottle. However, at the reduced
temperature of
60°C, molds often present a persistent problem in the cleaning and
reuse of PET bottles.
PET bottles simply cannot be washed like glass. Glass bottles are normally
washed at 80°C. Glass can also be washed with a relatively high
concentration of
caustic. While glass may be washed with up to 5.0% caustic, as little as 1.5%
caustic
can cause hazing in a PET container. With glass the washing temperature, the
caustic
concentration, and the washing time may be adjusted to allow for variability
within the
environment. In contrast, PET containers cannot withstand high levels of any
of these
variables.
While various alternatives have been proposed such as lowering the level of
caustic, there remains a need in the industry for compositions and methods
which allow
for the efficient cleaning of PET containers and multiple reuse events.
Summary of the ~mvea~on
The first aspect of the invention is a method for cleaning a polyethylene
terephthalate container. The method includes combining a first concentrate
with a
second concentrate in an alkaline wash solution. The first concentrate
includes from
about 0.3 to 25 wt-% of a surfactant and from about 5 to 30 wt-% of an acid.
The
second concentrate includes from about 8 to 60 wt-% of a builder. The method
further
includes the step of contacting the PET container with the wash solution
wherein the
removal of soil is undertaken with minimal hazing of the container.
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An additional aspect of the invention is a method for cleaning polyethylene
terephthalate containers which includes contacting the container with an
alkaline wash
solution having a temperature ranging from about 50°C to 60°C.
The alkaline wash
solution is formulated from a first concentrate, a second concentrate, an
alkalinity
source, and a balance of water. The first concentrate includes a nonionic
surfactant, a
first builder, and acid in an amount effective to provide a phase stable
solution. The
second concentrate includes a nonionic surfactant and a second builder. The
first and
second concentrate are present in the wash solution in a concentration ranging
from
about 0.5 wt-% to I .2 wt-%, and the first nonionic surfactant has a cloud
point ranging
from about 5°C to 60°C.
A further aspect of the invention is an alkaline wash solution for cleaning
polyethylene terephthalate bottles. The wash solution includes from about 1 to
5 wt-
of a source of alkalinity, from about 480 to 4000 ppm of a builder, from about
6 to 500
ppm of a surfactant, and from about 20 to 800 ppm of a coupler.
The invention is compositions and methods for cleaning polyethylene
terephthalate (PET) bottles with enhanced removal of mold and reduced hazing.
In
addition to the I to 3 wt-% caustic commonly used in PET bottle washing
procedures,
the compositions of the invention include surfactants and builder combination,
which
heightens cleaning and removes mold.
Hazing generally results from chemical etching caused by caustic present in
the
wash solution. Hazing is a clouding or dulling of the PET container surface
which
detracts from the aesthetic character of the container. Surprisingly, it has
been found
that by using surfactants with appropriate cloud points, hazing may be
substantially
reduced. Preferably, PET containers treated with the wash solution of the
invention are
substantially free of hazing.
Further, mold growth, particularly in the inside of returned PET bottles,
proves
to be a major challenge in bottle washing. Molds are very difficult to remove,
even with
a solution having as much as 3% caustic. Good cleaning usually removes most of
the
organic components of mold. However, the inorganic residues of mold may remain
on
the PET container surface. This may cause a problem similar to water spots.
This
condition gives a positive test result by methylene blue staining, (Industrial
Code of
Practice for Refillable PET Bottles, Edition 1 (1993-1994 UNESDA/CESDA, pg. V-
18). The compositions and methods of the invention substantially remove soils
and
both the organic and inorganic residues of mold.
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Detailed Description of the Invention
The Com osp ition
Generally, the wash solution of the invention is formulated from two
concentrate
compositions. These two concentrate compositions are combined in an aqueous
wash
solution with an alkalinity source, before use. These concentrate compositions
generally comprise surfactants, an acid, builders such as sequestrants and
chelating
agents, coupling agents, and various other adjuvants.
A. The Surfactant S, s
Generally, the compositions of the invention comprise surfactants to
facilitate
low foaming cleaning, and prevent hazing of the PET container. Any number of
surfactants may be used in accordance with the invention~including nonionic
surfactants,
anionic surfactants, amphoteric surfactants, and mixtures thereof.
Nonionic surfactants encompass a wide variety of polymeric compounds which
include specifically, but not exclusively, ethoxylated alkylphenols,
ethoxylated aliphatic
alcohols, ethoxylated amines, ethoxylated ether amines, carboxylic esters,
carboxylic
amides, and polyoxyalkylene oxide block copolymers.
Preferably, nonionic surfactants are used in the invention such as those which
comprise ethylene oxide moieties, propylene oxide moieties, as well a mixtures
thereof,
and ethylene oxide-propylene oxide moieties in either heteric or block
formation.
Additionally useful in the invention are nonionic surfactants which comprise
alkyl
ethylene oxide compounds, alkyl ethylene oxide-propylene oxide compounds and
alkyl
ethylene oxide-butylene oxide compounds, as well as mixtures thereof. The
ethylene
oxide propylene oxide moiety and ethylene oxide-butylene oxide moiety may be
in
either heteric or block formation. Also useful in the invention are nonionic
surfactants
having any mixture of combination of ethylene oxide-propylene oxide moieties
linked
to an alkyl chain where the ethylene oxide and propylene oxide moieties may be
in any
randomized or ordered pattern and of any specific length. Nonionic surfactants
useful in
the invention may also comprise randomized sections of block and heteric
ethylene
oxide propylene oxide, or ethylene oxide-butylene oxide.
Preferred nonionic surfactants include alkylphenols, alcohol ethoxylates, and
block copolymers of ethylene oxide and propylene oxide.
Examples of nonionic surfactants found useful in the invention include
(EO)/(PO) block copolymers having at least about 3 moles (E0) and at least
about 15
moles (PO); aryl or aliphatic ethoxylates having at least about 3 moles (E0)
which may
or may not be capped with methyl, butyl, or benzyl moieties; aryl or aliphatic
ethoxylate-propoxylate copolymers having at least about 2 moles of (E0) and
from
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about 4 moles of (PO) and which may also be capped with methyl, butyl or
benzyl; and
aryl or aliphatic ethoxylate-butoxylate copolymers having at least about 2
moles of (E0)
and about 4 moles of (BO) and which may also be capped with methyl, butyl or
benzyl.
The aliphatic group may comprise any branched or linear Cg-Cz4 moiety. The
aryl
group may generally comprise aromatic structures such as benzyl. An HLB value
of 4
to I 3 may also be used to characterize surfactants useful in the invention.
Representative nonionics which are useful in the invention include EO/PO block
copolymers available from Henkel KGaA; Pluronic L62 and L44 which are EO/PO
block copolymers available from BASF; Tergitol 15-S-3, TMN3, TMN10 which are
ethoxylated alcohols available from Union Carbide; Surfonic L24-1.3 which is a
linear
alcohol Pthoxylate available from Texaco Chemical Co.; nonyl phenol
ethoxylates such
n~
as NPE 4.5, NPE 9, and Surfonic N 120 available from Texaco Chemical Co.;
ethoxylated alkyl amines such as ethoxylated coco amine available from Sherex
Chemical Co. as Varonic K-215; an alkyl ethoxylated carboxylic acid such as
Neodex ~
23-4; and benzylated alcohol ethoxylates and EO/PO block copolymers among
other
nonionic surfactants.
Also useful in the invention are low foaming surfactants which may oil out of
the wash solution at a temperature of 59°C or less. Preferably, the
surfactant system
comprises surfactants having a cloud point of about 5°C to 60°C,
preferably from about
10°C to 50°C, and more preferably of about 10 to 20°C so
that in the alkaline wash
solution, the surfactants will oil-out or film and deposit on the PET
container surface
providing protection against hazing.
One preferred line of surfactants includes Dehypon LT104 which is a C,2_1g
fatty
alcohol (EO),o butyl capped and LS24 which is a C,2_,4 fatty alcohol ((E0}2
(P0)4) both
available from Henkel Canada Ltd.
Anionic surfactants may also be used in the invention. Typical commercially
available anionic surfactants provide either a carboxylate, sulfonate, sulfate
or
phosphate group as the functional anion. We have found that carboxylate based
anionic
surfactants such as alcohol ethoxylate carboxylates reduce hazing of the
container. A
commercial source of this type of surfactant is Neodox 23-4TM available from
Shell
Chemical Co.
Amphoteric surfactants may also be used in the invention. Such amphoteric
surfactants include betaine surfactants, sulfobetaine surfactants, sarcosinate
surfactants,
amphoteric imidazolinium derivatives and others. Certain surfactants found
useful irt,~
hazing reduction include cocoyl and lauroyl sarcosine/sarcosinates such as
Hamposyl C
and L available from Hampshire Chemical Co.
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B.
The composition of the invention rnay also comprise an acid source. The acid
functions to stabilize the surfactant system so that prior to mixing in the
wash solution,
the concentrate is a true phase stable solution. Once added to the alkaline
wash solution
S the acids are neutralized, become salts, and provide heightened cleaning
efficacy and
retard the formation of scaling on washing machine components. Generally, the
acid
may be any number of organic or inorganic acids.
Inorganic acids useful in the composition and the invention include phosphoric
acid, polyphosphoric acid or acidic pyrophosphate salts, among others. Organic
acids
useful in the invention include mono and polycarboxylic acids such as acetic
acid,
hydroxyacetic acid, citric acid, gluconic acid, glucoheptanoic acid, lactic
acid, succinic
acid, malonic acid, glutaric acid, and mixtures thereof.
C. Builders
The composition of the invention may also comprise a builder. Builders, i.e.,
sequestrants and chelating agents, retard the precipitation of scale onto the
side walls of
the PET container and the bottle washing machine. Builders also facilitate
soil
suspension, bind hardness ions and, in turn, enhance cleaning, during the
washing
process. In accordance with one embodiment of the invention the first
concentrate may
contain a first builder and the second concentrate may contain a second
builder.
Builders which may be used in accordance with the invention include
sequestrants such as phosphonates, phosphinates, acrylates and polyacrylates,
and
polycarboxylates, among others. Also useful as builders are maleate polymers
and
copolymers of maleate and acrylate; salts such as polyaspartic and
polyglutaric acid
salts; erythorbic acid; polyacrylamidopropyl sulfonate; and phosphino
carboxylic acid,
among others.
Water soluble acrylic polymers which may be used include polyacrylic acid,
polymethacrylic acid, acrylic acid-methacrylic acid copolymers, hydrolyzed
polyacrylamide, hydrolyzed methacrylamide, hydrolyzed acrylamide-
methacrylamide
copolymers, and mixtures thereof. Water soluble salts or partial salts of
these polymers
such as their respective alkaline metal (for example sodium or potassium) or
ammonium
salts can also be used.
Also useful as builders are phosphoric acids and phosphoric acid salts. Such
useful phosphoric acids include, mono, di, tri, tetra and, penta phosphoric
acids which
can contain groups capable of forming anions under alkaline conditions.
The phosphoric acid may also comprise a lower molecular weight
phosphonopolycarboxylic acid such as one having about 2-4 carboxylic moieties
and
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about 1 to 5 phosphonic acid groups. Such acids include 1 phosphono-1-
methylsuccinic
acid, phosphonosuccinic acid and 2-phosphonobutane-1,2,4 tricarboxylic acid.
Preferred sequestrants include the Dequest~ sequestrants available from
Monsanto Co. including bequest 2006~ which is amino tri(methylene phosphonic
acid)
pentasodium salt; bequest 2010~ which is 1-hydroxyethylidene-1,1-diphosphonic
acid;
Bayhibit AM~ available from Mobay Chemical Co. which is 2-phosphonobutane-
1,2,4-
tricarboxylic acid; bequest 2000~ which is anninotri(methylene phosphoric
acid); and
Belsperse 161 ~ from Ciba Geigy which is a phosphino polycarboxylic acid.
The builder present in either concentrate may also be a chelating agent.
Unlike a
sequestrant, the chelating agent tends to bind alkali earth metals present in
the wash
solution and hold these compounds in solution. It is believed that mold uses
the organic
portion of nutrients leaving behind inorganic salts. As a result, the
ineffective removal
of mold is often indicated by inorganic salts which are left behind on the
surface of the
PET container. The chelating agent removes these inorganic salts that are
found
underneath the mold.
The number of bonds capable of being formed by a chelating agent upon a single
hardness ion is reflected by labeling the chelating agent as bidentate (2),
tridentate (3),
tetradendate (4), etc. Any number of chelatin~; agents may be used in
accordance with
the invention. Representative chelating agent', include salts of amino
carboxylic acids,
phosphoric acid salts, water soluble acrylic polymers, among others.
Suitable amino carboxylic acid chelating agents include N-
hydroxyethyliminodiacetic acid, nitrilotriacetic acid (NTA),
ethylenediaminetetraacetic
acid (EDTA), N-hydroxyethyl-ethylenediamin.etriacetic acid (HEDTA), and
diethylenetriaminepentaacetic acid (DTPA), as well as isoserine-N,N-diacetic
acid, beta
alanine N,N-diacetic acid, sodium glycolate, and tripolyphosphate, among
others. In
accordance with one useful aspect of the invention the second builder present
in the
second concentrate comprises an amino carboxylic acid chelating agent,
preferably of
ethylene diamine tetracetic acid or salts thereof.
D. Couplers
_ The composition of the invention may also include a coupling agent. The
coupling agent functions to stabilize the concentrate composition so that it
is a true
phase stable solution.
To this end, any number of organic coupling agents may be used including
sulfates, sulfonates, as well as monofunctional and polyfunctional alcohols.
Preferred
coupling agents include sulfonate and sulfate compounds such as sodium xylene
sulfonate, sodium cumene sulfonate, sodium toluene sulfonate, 2-ethylhexyl
sulfate,
alkyl diphenyi oxide disulfonate where the alkyl group is either a branched
C12 or a
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linear Coo, sodium alkyl naphthalene sulfonate, and sodium octane sulfonate
and
disulfonate, and mixtures thereof.
Those coupling agents which have been found useful include linear alkyl
alcohols such as, for example, ethanol, isopropanol, and the like. Also useful
are
polyfunctional hydroxy compounds such as alkylene glycols like hexylene glycol
and
TM
propylene glycol; phosphate esters including Gafac RP710 from Rhone-Poulence
TM
Chemicals, and Triton H-66 from Rohm & Haas Co.
E. d'u an
The compositions and methods of the invention may use any number of other
adjuvants such as added nonionic surfactant defoamers such as those disclosed
in U.S.
Patent No. 5,516,451 to Schmitt et al.
Tracing compounds such as potassium iodide, colorants and dyes, fragrances,
and
preservatives, among other constituents are also useful in the invention.
The Method of Use
The method of the invention provides heightened cleaning efficacy of PET
containers, removing soils, inorganic salts, and molds while retarding hazing
of the
containers. This result is obtained by formulating a first acidic concentrate
with a high
concentration of surfactant and a separate second concentrate having a high
concentration of builder.
In accordance with one aspect of the invention the first and second
concentrates
may be incompatible if mixed separately from a wash solution. Incompatibility
in this
context stems from different pH requirements of the two different
concentrates. The
first concentrate may generally have an acidic pH of less than about 2 to
maintain the
solubility of the surfactant system. The pH of the second concentrate is
selected to
provide complete solubility of the builder and is generally alkaline.
Combination of the
two concentrates before dilution in the wash solution may result in phase
separation of
the surfactant system or the builder depending on pH.
In use the two concentrates are combined in an alkaline wash system to provide
heightened cleaning efficacy with good building efficacy. Illustrative
concentration
ranges for each of the two concentrates are provided below:
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TABLE 1
Concentration (wt-°.io)
More
Conce~:rate 1 Useful ~;ferred P~efeyred
Surfactant System 0.3-25 1-15 3-10
First Builder 0-20 5-20 10-20
Coupler 1-40 30-20 5-15
Acid (100% w/w) 5-30 10-20 10-15
Water q.s. q.s. q.s.
Surfactant System 0-10 0.1-5 0.1-1
Second Builder 8-60 15~-45 30-45
Water q.s. q.s. q.s.
Use Solution (nnml.
Surfactant 6-500 20-300 60-200
Builder 480-4000 1000-3000 2000-3000
Coupling Agent 20-800 60-400 100-300
In use this system is diluted into a wash solution comprising from about 0.1
wt-% to 0.8 wt-%, preferably from about 0.2 wt-% to 0.3 wt-% of the first
concentrate
and from about 0.2 to 1.2 wt-%, and preferably from about 0.4 wt-% to 0.8 wt-%
of the
second concentrate. The ratio of the first concentrate to the second
concentrate in the
alkaline wash solution generally ranges from about 0.1:0.5 to 0.1:1.0, and
preferably
from about 0.1:0.2 to 0.15:0.3. Generally the alkaline wash solution may have
a total of
from about 0.3 to 2.0 wt-% and preferably from about 0.5 to 1.2 wt-% of both
concentrate 1 and concentrate 2.
In accordance with one preferred aspect of the invention, the wash solution
comprises at least about 1000 ppm EDTA, at least about 5 ppm of a phosphonate
compound, and at least about 100 ppm of a gluconate compound.
The washing of PET containers generally takes place over a number of steps.
The PET containers are emptied and pre-rinsed, then soaked in the wash
solution. The
wash solution generally has anywhere from 1.17 wt-% to 5 wt-% and preferably
from
i .5 wt% to 3 wt-% caustic (NaOH). Into this system is mixed Concentrate 1 and
Concentrate 2 into which the PET containers are applied. Washing tends to take
place
over a time period which ranges from about 7 to 20 minutes. The wash
temperature is
about 59°C ~ 1°C. The containers then pass through a weak
caustic stage where water is
run into the tank to continue cleaning and begin rinsing by reducing the
sodium
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hydroxide concentration. The caustic concentration may be maintained by a
conductivity controller. The containers then pass through at least three rinse
stages
which sequentially rinse the containers with warm water and cold water. The
final
rinsing takes place with potable water after which time the containers are
turned upright,
5 inspected, and filled.
EXAMPLES
The following working examples provide a nonlimiting illustration of the
invention.
10 WORKING EXAMPLE 1
Hazing was studied using various compositions as detailed. Provided below in
Table 2 are examples which were tested along with other compositions in Table
3.
TABLE 2
COMPOSITIONS EXAMPLE EXAMPLE
IA IB
H3PO4 (75% W/w) 10.00
Gluconic acid (50% wlw) 10.00
Dehypon LT-104 11.00
(C12-t8 H24.37 ~~)IO
~nC4H9)
Dehypon LS-24 5.00
(Cm-ie Hzs-av (EO)z
(P0)4 OH)
Triton BG-10 1.00
(alkyl polyglucoside)
bequest 2000~ (50% 6.00 6.00
w/w)
(amino trimethylene
phosphonic acid)
bequest 2010 (60% 2.00
w/w)
( I-hydroethylidene-I,
1-diphosphonic acid)
Bayhibit-AM~ (50% 3.00
w/w)
(2-phosphonobutane-1,
2, 4-
tricarboxylic acid)
Ethylene Diamine 39.00
Tetra-
Acetic Acid, Tetrasodium
salt (powder)
Sodium Cumene Sulfonate30.00
(40% w/w)
VN-11 0.50
(oleyl alcohol diethylene
glycol)
Potassium Iodide 0.25
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Chemical hazing was studied with PET strips (0.5" x 2") which were cut out o:f
amorphous (low crystallinity) PET sheeting. The strips were immersed in about
200
mL of 2.8% caustic solutions containing various amounts of additives being
tested. The
solutions were shaken at 100 rpm in a water bath with a temperature maintained
between 58-60°C for 24-72 hours. The degree of hazing/corrosion was
evaluated
visually and gravimetrically using water (hazing rating of 0) and a 2.8%
caustic solution
(hazing rating of 10) as references.
EXAMPLE ACTIVE CONCENTRATION HAZING
1 A Table 2 0.05 wt-% 0.5
1 A Table 2 0.2 wt% 0.5
1 A Table 2 - 0.6 wt-% 0.5
1 A Table 2 2.0 wt-% 0.5
1 B Table 2 0.05 wt-% 10
1 B Table 2 0.1 wt-% 7.5
1 B Table 2 0.2 wt-% 5.5
1B Table 2 0.35 wt-% 1.5
1 C Dehypon LT 104 (C,z_, 10 ppm 0
g H24-37
(EO)to ~nC4H9)
1D Dehypon LS24 (C~2-~q 10 ppm 1
H25-29
(EO)z (P0)4 OH)
IE Triton BG-10 300 ppm 8
(alkyl poly glucoside
(70% w/w))
1 F Glucopon 600 500 ppm 10
(alkyl polyglucoside
(C~z.g Hz7.6
O(C6H i oOs)o-3H))
1G Sodium Cumene Sulfonate300 ppm 9
Control 1 Water 0 wt-% ' 0
Control 2 Caustic 2.8 wt-% 10
Hazing was measured against a scale of 0 for no hazing such as with water and
10 for
2.8% caustic. Examples 1 C and 1 D, as well as the series of trials run on
Example 1 A
proved these compositions to be very effective in preventing hazing whether
used alone
or in conjunction with sequestrants.
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WORKING EXAMPLE 2
A second analysis of hazing was undertaken using the method of Example 1
with 100 ppm of each active (EXS. 2A-2W), and 2.8 wt-% of NaOH in the wash
water
(except for the control); the results are reported in Table 4.
1e
EXAMPLEACTIVE HAZING
2A (PO~4(EO)lsI(PO)13.0(E~15.5)~(E~)15(P~)24
2B (PO),3(EOysI(EO)z.z(~)zs.s)(EO)~s(POys0
2C (PO)s(EO),sI(PO)a_o(EO~s.s)~(EOOs(PO)zeI
2D Pluronic L62 0
HO(EO)"(PO)3o(EO)gH
2E Pluronic L44 0
HO(EO)"(PO)z,(EO)"H
2F Tergito115-S-3 0
(C ~ t-~ sHzs.3 ~ (EO)sOH)
2G Tergitol TMN 3 0
C mHzs(EO)30H
2H Tergitol TMN IO 0
C mI"IZS(EOOoOH
2I Surfonic L24-1.3 0
(C~zaa(EO)t.sOH)
2J Plurafac LF 13 I 15
(C,2,~(EO)~(BO),.,OCH3)
2K Dehypon LT104 0
(Ciz.is Hz4.3~ (EO)io OnCaH9)
2L (C6HsCHz)-(PO)n(EO)isl(EO)z.z~(PO)zs.s~(EO)~s(POO3-0
(CfI2C6Hs)
2M Ciz-~40(EO)io_~z-CHz-C6Hs 0
2N NPE 4.5 2
nonyl phenol (EO),,s
20 NPE 9.5 _ - 0
nonyl phenol (EO)9,s
2P SurfonicN120 6
C9H,9Cbi-I4(EO),ZOH
2Q Neodox 23-4 4
(C, z. I 3(EO)40CH2COOH)
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2R Varonic IC215 4
(cocoamine ethoxylate (E0),5)
2S Hamposyl C I
coco sarcosine (C,Z.,sH2s-37C(O)N(CH3)CHZCOOH)
2T Hamposyl L 4
lauroylsarcosine
2U HamposyI L 30 10
sodium laroyl sarcosinate
2V Silwet L77 5
(CH3)3SiOSi[(CH3)OSi(SH3)3j[(CHZ)3(EO)eOCH3j
2W 2.8% NaOH (control) 10
CA 02271819 1999-OS-13
WO 98/22566 PCT/US96/18261
14
WORKING EXAMPLE 3
Soiled bottles from the field were cut into test panels (roughly 2" x 3"). A
washing test was done in 1000 mL solution with stirring (500 rpm) for 10 min.,
followed by a 1 min. water rinse (8 psi nozzle spray, top down). Methylene
blue
staining was used to evaluate soil level both before and after the cleaning in
accordance
with the Industrial Code of Practice for Refillable Pet Bottles, Edition 1
(1993-1994
LJNESDA/CESDA), page V-18. The above steps were repeated every 10 minutes for
the 20 minute and 30 minute cleaning iterations. The wash solution comprised
2.8 wt-
caustic, 0.6 wt-% Example 1 B, and the varying amounts of Example 1 A as shown
in
Table SA below. Quadruplet data was used for statistical average. The data was
reported as total cleaned/total washed.
Ta a
2.8% caustic
0.6% Example 1
B
Cleaning Time
Example 1A (wt-%)10 min 20 min 30 min
0.05 1/4 1/4 2/4
0.10 1/4 2/4 2/4
0.15 2/4 3/4 3/4
0.20 2/4 2/4 3/4
0.25 3/4 3/4 3/4
0.30 4/4
Tab a
In this example the wash solution comprised 2.8 wt-% caustic and 0.2 wt-
Example 1 A, with varying amounts of Example 1 B as indicated below. Data was
reported as in Table SA.
Cleaning Time
Example 1B (wt-%) 10 min 20 min 30 min
0.60 2/4 2/4 2/4
1.20 4/4
0.80 4/4
CA 02271819 1999-OS-13
WO 98/22566 PCT/US96/18261
Table 5,~
Different concentrations
of Example 1,A and
1B were combined to
test cleaning
efficacy. Data was reported
as in Tables
SA and SB.
Cleaning Time
Example 1 A Example 1
B
(wt-%) (wt-%) 10 min 20 min 30 min
0.10 1.20 3/4 3/4 3/4
0.15 I.20 3/4 3/4 3/4
0.20 I .20 4/4
0.10 I .80 3/4 3/4 3/4
0.1 S 1.80 3/4 4/4
0.20 1.80 --- 4/4
0.20 0.7 2/4 2/4 3/4
0.20 0.8 2/4 2/4 3/4
0.20 1.0 4/4
0.30 0.4 2/4 2/4 2/4
0.40 0.4 2/4 2/4 2/4
5
a 1 .5D
The cleaning efficacy of wash solutions having set concentrations of Example
I A and Example 1 B with varied concentrations of caustic was then analyzed.
Example
IA was added at~0.2 wt-% to the wash solution and Example 1B was added at 0.8
wt-
10 to the wash solution. The results are reported lbelow in the same manner as
Tables SA -
SC.
Cleaning Time
Caustic (wt-%) 10 min 20 min 30 min
1.5 2.4 2.4 3/4
2.0 2/4 2/4 4/4
2.6 3/4 3/4 4/4
The above specification, examples and data provide a complete description of
15 the manufacture and use of the composition of the invention. Since many
embodiments
of the invention can be made without departing from the spirit and scope of
the
invention, the invention resides in the claims hereinafter appended.
