U.S. patent application number 12/731403 was filed with the patent office on 2010-10-07 for cold temperature stable biocidal composition.
Invention is credited to John Pohlman.
Application Number | 20100251602 12/731403 |
Document ID | / |
Family ID | 42790725 |
Filed Date | 2010-10-07 |
United States Patent
Application |
20100251602 |
Kind Code |
A1 |
Pohlman; John |
October 7, 2010 |
COLD TEMPERATURE STABLE BIOCIDAL COMPOSITION
Abstract
Provided is a synergistic biocidal composition comprising a
biocidal N-(2-nitroalkyl) morpholine compound of formula I:
##STR00001## where R, x, and y are as defined herein, together with
an aromatic alcohol. The composition is cold temperature stable and
is therefore useful for the control of microorganisms in a variety
of matrices, including liquid fuels.
Inventors: |
Pohlman; John; (Skokie,
IL) |
Correspondence
Address: |
The Dow Chemical Company
P.O. BOX 1967
Midland
MI
48641
US
|
Family ID: |
42790725 |
Appl. No.: |
12/731403 |
Filed: |
March 25, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61166934 |
Apr 6, 2009 |
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Current U.S.
Class: |
44/334 |
Current CPC
Class: |
C10L 1/231 20130101;
C10N 2030/16 20130101; C10L 1/2335 20130101; A01N 43/84 20130101;
C10M 2215/226 20130101; A01N 33/18 20130101; C10N 2040/20 20130101;
C10N 2040/36 20130101; C10L 10/00 20130101; C10M 133/50 20130101;
A01N 33/18 20130101; A01N 31/04 20130101; A01N 31/14 20130101; A01N
33/18 20130101; A01N 2300/00 20130101; A01N 43/84 20130101; A01N
2300/00 20130101 |
Class at
Publication: |
44/334 |
International
Class: |
C10L 1/233 20060101
C10L001/233 |
Claims
1. A cold temperature stable biocidal composition comprising: a
compound of the formula I: ##STR00004## where R is hydrogen, methyl
or ethyl; x is 1 or 2; y is 0 or 1, and the sum of x and y is 2;
and an aromatic alcohol.
2. The cold temperature stable biocidal composition of claim 1,
wherein R is ethyl.
3. The cold temperature stable biocidal composition of claim 1,
wherein y is 1.
4. The cold temperature stable biocidal composition of claim 1,
wherein y is 0.
5. The cold temperature stable biocidal composition of claim 1,
wherein the compound of formula (I) is selected from:
N-(2-nitroethyl)morpholine, N-(2-nitropropyl)morpholine,
N-(2-nitrobutyl)morpholine, 2-nitro-1,3-dimorpholinopropane,
2-methyl-2-nitro-1,3-dimorpholinopropane,
2-ethyl-2-nitro-1,3-dimorpholinopropane, and mixtures of two or
more thereof.
6. The cold temperature stable biocidal composition of claim 1,
wherein the compound of formula (I) comprises a mixture of
N-(2-nitrobutyl)morpholine and
2-ethyl-2-nitro-1,3-dimorpholinopropane.
7. The cold temperature stable biocidal composition of claim 1,
wherein the aromatic alcohol is selected from phenoxyethanol,
benzyl alcohol, and aromatic glycol ethers.
8. The cold temperature stable biocidal composition of claim 1,
wherein the compound of formula (I) comprises a mixture of
N-(2-nitrobutyl)morpholine and
2-ethyl-2-nitro-1,3-dimorpholinopropane and the aromatic alcohol is
phenoxyethanol.
9. A blend comprising a liquid fuel and the biocidal composition of
claim 1.
10. A blend according to claim 9 wherein the liquid fuel is
gasoline, diesel, biodiesel, a water-fuel emulsion, an
ethanol-based fuel, an ether-based fuel, diesel oil, fuel oil, or
kerosene based fuel.
11. A method for providing microorganism resistance to a matrix
susceptible to growth of microorganisms, the method comprising
including in the matrix an effective amount of the biocidal
composition of claim 1.
12. The method of claim 11 wherein the matrix is aqueous,
non-aqueous, or a mixture of aqueous and non-aqueous.
13. The method of claim 12 wherein the matrix is a metalworking
fluid, a die cast lubricant, a mold release agent, a paint, paint
spray booth wash water, a coating, an adhesive, a caulk, a sealant,
a mineral slurry, an ink, petroleum (crude oil), or a liquid
fuel.
14. The method of claim 13 wherein the liquid fuel is gasoline,
diesel, biodiesel, a water-fuel emulsion, an ethanol-based fuel, an
ether-based fuel, diesel oil, fuel oil, or kerosene based fuel.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims benefit of priority from U.S.
Provisional Patent Application No. 61/166,934, filed Apr. 6, 2009,
which application is incorporated by reference herein in its
entirety.
FIELD OF THE INVENTION
[0002] The invention relates to cold temperature stable and
synergistic biocidal compositions suitable for use in various
aqueous and non aqueous matrices, such as liquid fuels.
BACKGROUND OF THE INVENTION
[0003] N-(2-nitroalkyl) morpholine compounds are a class of
biocides that are useful for controlling microorganism growth in a
variety of environments, such as industrial cooling water systems,
recycle process water systems, oil and gas recovery operations, and
in fuels. FUELSAVER.TM., which is based on a mixture of
N-(2-nitrobutyl)morpholine and
2-ethyl-2-nitro-1,3-dimorpholinopropane, is an example of a
commercially available N-(2-nitroalkyl) morpholine biocide that is
used for preserving fuels.
[0004] While N-(2-nitroalkyl) morpholines are effective biocides,
many crystallize at temperatures above 0.degree. C. Such biocides,
therefore, are generally unsuitable for cold temperature
applications, storage, or transport.
[0005] It would be an advance in the art to provide formulations of
N-(2-nitroalkyl) morpholines that are cold stable, particularly
those that are stable (i.e., do not freeze) at temperatures as low
as -20.degree. C. It would also be an advance to provide
formulations that exhibit enhanced activity against a broad
spectrum of microorganisms.
BRIEF SUMMARY OF THE INVENTION
[0006] In one aspect, the invention provides a biocidal composition
that is stable at low temperature and exhibits synergistic
behavior. The composition comprises an N-(2-nitroalkyl) morpholine
compound of formula I:
##STR00002##
where R, x, and y are as defined herein, together with an aromatic
alcohol.
[0007] In another aspect, the invention provides a fuel blend. The
fuel blend comprises a liquid fuel and the cold temperature stable
biocidal composition described herein.
[0008] In a further aspect, the invention provides a method for
imparting microorganism resistance to a matrix in need of such
resistance. The method comprises including in the matrix an
effective amount of the biocidal composition described herein.
DETAILED DESCRIPTION OF THE INVENTION
[0009] As noted above, the invention provides cold temperature
stable biocidal compositions. In particular, compositions according
to the invention have been found to be freeze stable (i.e., do not
freeze) to temperatures as low as -20.degree. C. This occurs even
though the individual components of the composition are not
themselves freeze stable at the same temperatures.
[0010] In addition to cold temperature stability, compositions
according to the invention also exhibit improved control of
microorganism growth when compared to other non-inventive cold
temperature stable formulations.
[0011] For the purposes of this specification, the meaning of
"microorganism" includes, but is not limited to, bacteria, fungi,
algae, and viruses. The words "control" and "controlling" should be
broadly construed to include within their meaning, and without
being limited thereto, inhibiting the growth or propagation of
microorganisms, killing microorganisms, disinfection, and/or
preservation against re-growth of microorganisms.
[0012] The composition of the invention comprises: a biocidal
N-(2-nitroalkyl) morpholine compound of the formula I:
##STR00003##
where R is hydrogen, methyl or ethyl; x is 1 or 2; y is 0 or 1, and
the sum of x and y is 2; and an aromatic alcohol.
[0013] Preferred biocidal compounds of formula I are those in which
R is ethyl.
[0014] Also preferred are compounds in which y is 1.
[0015] Additionally preferred are compounds wherein y is 0.
[0016] Specific examples of preferred compounds of formula I
include: N-(2-nitroethyl)morpholine, N-(2-nitropropyl)morpholine,
N-(2-nitrobutyl)morpholine, 2-nitro-1,3-dimorpholinopropane,
2-methyl-2-nitro-1,3-dimorpholinopropane,
2-ethyl-2-nitro-1,3-dimorpholinopropane, or mixtures of two or more
thereof.
[0017] More preferred are N-(2-nitrobutyl)morpholine and
2-ethyl-2-nitro-1,3-dimorpholinopropane.
[0018] Particularly preferred is a mixture of
N-(2-nitrobutyl)morpholine and
2-ethyl-2-nitro-1,3-dimorpholinopropane. In this embodiment, it is
further preferred that the weight ratio of
N-(2-nitrobutyl)morpholine to
2-ethyl-2-nitro-1,3-dimorpholinopropane is between about 20:1 and
about 10:1, more preferably between about 18:1 and about 14:1.
[0019] The aromatic alcohol used in the compositions of the
invention functions as a freeze stabilizer and also as an enhancer
of biocidal efficacy. Suitable aromatic alcohols include
phenoxyethanol, benzyl alcohol, and aromatic glycol ethers.
Preferred is phenoxyethanol.
[0020] The composition of the invention preferably comprises
between about 5 and 95 weight percent, more preferably between
about 15 and 75 weight percent, even more preferably between about
30 and 55 weight percent, and further preferably between about 38
and 44 weight percent of the N-(2-nitroalkyl) morpholine compound
based on the total weight of the biocide and the aromatic alcohol
in the composition.
[0021] An especially preferred composition according to the
invention comprises from about 38 to 44 weight percent of a mixture
of N-(2-nitrobutyl)morpholine and
2-ethyl-2-nitro-1,3-dimorpholinopropane and about 62 to 56 weight
percent of phenoxyethanol, based on the total weight of the mixture
of
N-(2-nitrobutyl)morpholine/2-ethyl-2-nitro-1,3-dimorpholinopropane
and the phenoxyethanol present in the composition.
[0022] The composition may contain other additives including, but
not limited to, other aromatic or non-aromatic solvents, glycolic
type solvents, and non-aromatic glycol ethers, as well as various
inert or byproduct material that may result from the synthesis of
the biocide and that are not removed during workup. In general, it
is preferred that the total amount of biocide compound and aromatic
alcohol comprise at least about 70 weight percent, more preferably
at least about 80 weight percent of the composition, based on the
compositions total weight.
[0023] As noted, more than one N-(2-nitroalkyl) morpholine compound
can be combined for use in the invention; in such cases, ratios and
concentrations are calculated using the total weight of all
N-(2-nitroalkyl) morpholine compounds present.
[0024] N-(2-nitroalkyl) morpholine compounds for use in the
invention are commercially available or can be readily prepared by
those skilled in the art using well known techniques (see e.g.,
U.S. Pat. No. 3,054,749 and Canadian patent 982475, both
incorporated by reference). Aromatic alcohols are also commercially
available or can be readily prepared.
[0025] The compositions of the invention are useful at controlling
microorganism growth in a variety of aqueous and non-aqueous
matrices and in matrices that are mixtures of aqueous and
non-aqueous components. Examples include, but are not limited to,
metalworking fluids, die cast lubricants, mold release agents,
paints, paint spray booth wash water, coatings, adhesives, caulks,
sealants, mineral slurries, inks, petroleum (crude oil), or liquid
fuels such as gasoline, diesel, biodiesel, water-fuel emulsions,
ethanol-based fuels, ether-based fuels, diesel oil, fuel oil, or
kerosene based fuels. Because of their cold temperature stability,
the compositions of the invention are particularly suitable for
controlling microorganisms in liquid fuels.
[0026] A person of ordinary skill in the art can readily determine,
without undue experimentation, the effective amount of the
composition that should be used in any particular matrix to provide
microorganisms control. By way of illustration, a suitable
effective amount (total for the N-(2-nitroalkyl) morpholine
compound(s) and the aromatic alcohol) is at least about 25 ppm or
at least about 500 ppm, by weight. Typically, the amount is less
than about 20,000 ppm or less than about 2500 ppm, by weight.
[0027] The components of the composition of the invention can be
added to the matrix separately or they can be preblended prior to
addition. A person of ordinary skill in the art can readily
determine the appropriate method of addition. Preblending is
preferred.
[0028] The following examples are illustrative of the invention but
are not intended to limit its scope. Unless otherwise indicated,
ratios, percentages, parts, and the like used herein are by
weight.
EXAMPLES
[0029] In the Examples below, the following compositions are
tested: [0030] Sample A: a comparative composition that contains an
86 weight percent mixture of N-(2-nitrobutyl)morpholine and
2-ethyl-2-nitro-1,3-dimorpholinopropane as the biocidal actives
(NBM/ENDM). The ratio of NMB/ENDM is 16.2:1. The balance of the
composition are inerts/byproducts created during the synthesis of
the biocidal actives. The composition does not contain
phenoxyethanol. Available from The Dow Chemical Company as
FUELSAVER.TM. Antimicrobial. [0031] Sample B: an inventive
composition that contains about 55 weight percent of phenoxyethanol
and about 45 weight percent of Sample A.
[0032] Sample C: a comparative composition that is freeze stable
and that contains a mixture of about 55 weight percent tripropylene
glycol methyl ether as a freeze stabilizer and about 45 weight
percent of Sample A. The composition does not contain
phenoxyethanol. [0033] Phenoxyethanol (PHE): an aromatic alcohol
obtained from The Dow Chemical Company as DOWANOL.TM. EPh. [0034]
Tripropylene Glycol Methyl Ether (TPM): a non-aromatic alcohol that
can be used as a freeze stabilizer. It is available from The Dow
Chemical Company as DOWANOL.TM. TPM.
Example 1
Freeze-Thaw Stability Testing
[0035] Sample A (comparative composition), Sample B (inventive),
and phenoxyethanol (comparative) are placed in a -20.degree. C.
freezer for 24 hours, removed and observed for freezing. Samples
are thawed completely and then replaced in the freezer for another
24 hour period. This procedure is carried out for five cycles in
which the samples are placed in the freezer for five 24 hour
periods. Sample size is 5 ml in a clear glass container with a
Bakelite screw top. Results are summarized in Table 1.
TABLE-US-00001 TABLE 1 Freeze Thaw Study: 5 Cycle in -20.degree. C.
Freezer In: Out: Thawed In- Out: Thawed In- Out: Thawed In: Out:
Thawed In- Out: Thawed Sample Day 1 3 hours Day 2 3 hours Day 3 3
hours Day 4 3 hours Day 5 3 hours Sample B Not Not Not Not Not Not
Not Not Not Not (inventive) frozen frozen frozen frozen frozen
frozen frozen frozen frozen frozen Sample A Frozen Thawed Frozen
Thawed Frozen Thawed Frozen Thawed Frozen Thawed (comparative)
Phenoxyethanol Frozen Thawed Frozen Thawed Frozen Thawed Frozen
Thawed Frozen Thawed (comparative)
[0036] As can be seen from the data in Table 1, the inventive
composition (Sample B) does not freeze even though the individual
ingredients, the biocide mixture (Sample A) and the phenoxyethanol,
both freeze under the same temperature conditions.
Example 2
Microbial Control Experiments
[0037] This example compares the efficacy of compositions of the
invention to non-inventive compositions, in diesel fuel, against
various microorganisms.
[0038] Procedure
[0039] Bacteria: Pseudomonas aeruginosa (ATCC# 33988), Yeast:
Yarrowia tropicalis (ATCC# 48138), and Mold: Hormoconis resinae
ATCC# 20495, are sub-cultured in Bushnell-Haas broth, and used for
the inoculum of this example. Bushnell-Haas broth is used as the
aqueous phase below the diesel fuel. Testing is carried out for 4
weeks. Microbial survival is measured using the plate count method.
Tryptic soy agar is used for Pseudomonas aeruginosa, and Sabouraud
dextrose agar with 0.5 ug/ml gentamycin for Yarrowia tropicalis,
and bacteriological grade agar 1.5%, with 0.01% potassium tellurite
for Hormoconis resinae. Bacteria are incubated at 37.degree. C. for
48 hours, and fungi at 25.degree. C. for 5-7 days.
[0040] Testing is carried out in glass bottles with bakelite screw
tops. Volumes: 130 ml diesel fuel over 25 ml synthetic water bottom
(Bushnell-Haas Broth). Tests are mixed weekly by turning the bottle
upside down 5 times.
[0041] The diesel fuel is obtained from Halternann Products
(Channelview, Tex.) Diesel fuel, with the following specifications:
2007 Certification Diesel, GMPT-5-0,9-; Product Number: HF 582b;
Product Code: 20582b.
[0042] Table 2 shows results for "Sample B", a composition
according to the invention. Table 3 shows results for "Sample C," a
comparative composition that is freeze stable. Table 4 shows
results for phenoxyethanol which is a component in Sample B, but is
not freeze stable by itself. Table 5 is a summary of the lowest
dosage required to reduce the concentration of viable
microorganisms to a <10 CFU/mL level for Samples B, C, and
phenoxyethanol.
TABLE-US-00002 TABLE 2 Biocidal Efficacy: Inventive Composition
Sample B Day Bacteria Yeast Mold Control (no biocide) 30 4.3E8
8.3E7 6.7E6 500 ppm 30 8.0E2 5.6E2 2.6E3 750 ppm 30 2.8E2 1.8E2
7.0E2 1000 ppm 30 <10 <10 3.8E2 1500 ppm 30 <10 <10
<10 2000 ppm 30 <10 <10 <10 2500 ppm 30 <10 <10
<10 Day 0: Bacteria 8.7E7 cfu/ml; Yeast 2.3E7 cfu/ml; Mold 4.6E6
cfu/ml
TABLE-US-00003 TABLE 3 Biocidal Efficacy: Comparative Composition
Sample C Day Bacteria Yeast Mold Control (no biocide) 30 4.3E8
8.3E7 6.7E6 500 ppm 30 9.0E3 1.3E4 6.8E4 750 ppm 30 7.8E3 5.6E3
1.1E4 1000 ppm 30 1.1E3 8.4E2 8.0E3 1500 ppm 30 4.0E2 2.8E2 3.9E3
2000 ppm 30 <10 6.0E1 7.0E2 2500 ppm 30 <10 <10 <10 Day
0: Bacteria 8.7E7 cfu/ml; Yeast 2.3E7 cfu/ml; Mold 4.6E6 cfu/ml
TABLE-US-00004 TABLE 4 Biocidal Efficacy: Phenoxyethanol Day
Bacteria Yeast Mold Control (not biocide) 30 4.3E8 8.3E7 6.7E6 500
ppm 30 4.7E6 2.0E6 7.3E5 750 ppm 30 1.3E6 7.2E5 6.7E5 1000 ppm 30
4.8E5 1.8E5 5.6E5 1500 ppm 30 6.0E4 7.3E4 9.0E4 2000 ppm 30 1.7E4
5.5E4 7.8E4 2500 ppm 30 9.6E3 2.3E4 5.5E4 Day 0: Bacteria 8.7E7
cfu/ml; Yeast 2.3E7 cfu/ml; Mold 4.6E6 cfu/ml
TABLE-US-00005 TABLE 5 Lowest dosage required to reduce the
concentration of viable microorganism to <10 CFU/mL level (ppm).
ppm of ppm of ppm of NMB/ENDM NMB/ENDM PHE in in ppm in Sample B
Sample B Sample C PHE Bacteria 387 550 774 >2500 Yeast 387 550
968 >2500 Mold 581 825 968 >2500
[0043] As can be seen from the data, the inventive composition
(Sample B) provides significantly improved microbial control
relative to the other low temperature stable formulation (Sample
C), as well as relative to phenoxyethanol which is not freeze
stable nor very effective as a microbial control agent.
Example 3
Synergy of Inventive Compositions
[0044] Sample A and Sample C were re-tested at the same biocidal
active concentrations using the test method described in Example 2,
except the test was carried out for 7 days and the microbial
survival was measured at 24 hour and at 7 days. The results are
summarized in Table 6.
TABLE-US-00006 TABLE 6 Comparison of the efficacy of Sample A and
Sample C at equivalent NMB/ENDM active concentrations Microbial
growth after biocide treatments at 24 h and 7 days NMB/ENDM
Bacteria Yeast Contact Concentration Sample Sample Sample Sample
time (ppm) A C A C 24 hours 0 (Control) 2.0E7 2.0E7 1.2E5 1.2E5 194
6.0E4 <10 1.1E4 2.7E3 387 <10 <10 <10 <10 774 <10
<10 <10 <10 7 days 0 (Control) 1.1E9 1.1E9 4.0E5 4.0E5 194
<10 <10 <10 <10 387 <10 <10 <10 <10 774
<10 <10 <10 <10 Day 0: Bacteria 4.0E6 cfu/ml; Yeast
6.1E6 cfu/ml; Mold 4.0E7 cfu/ml
[0045] As shown in Table 6, at equivalent active concentrations,
Sample A had generally lower efficacy than Sample C.
[0046] Because Sample A is generally less effective than Sample C
at the same active concentrations, the data results from Table 5
are used to determine the concentrations of NMB/ENDM in Sample C
that are required to achieve a <10 CFU/mL level, to estimate the
synergy index between NMB/ENDM and phenoxyethanol. Based on the
Synergy Index (SI) calculation equation below, the estimated
synergy indices for NMB/ENDM and phenoxyethanol are provided in
Table 7.
Synergy Index=Ca/CA+Cb/CB
[0047] Ca: Concentration of NMB/ENDM in Sample B required to reduce
the concentration of viable microorganism to <10 CFU/ml
level
[0048] CA: Concentration of NMB/ENDM required to reduce the
concentration of viable microorganism to <10 CFU/ml level when
used alone
[0049] Cb: Concentration of PHE in Sample B required to reduce the
concentration of viable microorganism to <10 CFU/ml level
[0050] CB: Concentration of PHE required to reduce the
concentration of viable microorganism to <10 CFU/ml level when
used alone [0051] <1: synergy
[0052] Synergy Index=1: additivity [0053] >1: antagonism
TABLE-US-00007 [0053] TABLE 7 Estimated synergy indices between
NMB/ENDM and phenoxyethanol ppm of ppm of ppm of NMB/ENDM in PHE in
NMB/ Sample B Sample B ENDM PHE Synergy (Ca) (Cb) (CA) (CB) Index
Bacteria 387 550 >774 >2500 <0.72 Yeast 387 550 >968
>2500 <0.62 Mold 581 825 >968 >2500 <0.93
[0054] The results in Table 7 illustrate that there is a
synergistic effect between NMB/ENDM and phenoxyethanol.
[0055] While the invention has been described above according to
its preferred embodiments, it can be modified within the spirit and
scope of this disclosure. This application is therefore intended to
cover any variations, uses, or adaptations of the invention using
the general principles disclosed herein. Further, the application
is intended to cover such departures from the present disclosure as
come within the known or customary practice in the art to which
this invention pertains and which fall within the limits of the
following claims.
* * * * *