Note: Descriptions are shown in the official language in which they were submitted.
~2(~69~3
Technical Fiela
The present invention relates to certain silyl
quaternary ammonium salts and a method of inhibiting the
growth of bacteria and fungi therewith. In particular,
the invention relates to the use of such salts as bacteri-
cidal or fungicidal agents on texti'es or other sub-
strates.
9~3
Backaround Art
.,
It is well known in the art that organosilicon
quaternary ammonium compounds possess bacteriostatic, fun-
gistatic and algaestatic and/or bactericidal, fungicidal
and algaecidal properties. See, for example, U.S.
Patents Nos. 3,560,385; 3,730,701; 3,794,736; 3,817,739;
3,865,728; and 4,~05,025; and British Patent No.
1,386,876~ Thus, U.S. Patent No. 3,730,701 discloses a
variety of silyl quaternary arnmonium compounds having a
single long chain alkyl radical of from 11 to 22 carbon
atoms. For example, one such compound, 3-(trimethoxy-
silyl)propyl octadecyldimethyl ammonium chloride is a com-
mercial antimicrobial product marketed by Dow Corning as
"Bioguard Q 9-5700" (EPA No. 34292-1~. U.S~ Patent No.
15 3,794,736 describes a number of other organosilicon amines
and salts thereo~ exhibiting antimicrobial activity
against a ~ide variety of organisms.
In accordance with this invention there are pro-
vided a number of silyl ~uaternary ammonium salts which
have equal or greater antimicrobial activity than the pre-
viously known compounds.
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Disclosure of Invention
The present invention relates to certain silyl
quaternary ammonium salts, particularly 3-(trimethoxy-
silyl)propyldidecylmethyl ammonium salts, e.g., the flu-
5 oride, chloride, bromide, iodide, sulfate,acetate and phosphatethereof, and their use as fungicides and bactericides on a
variety of substances having reactive surfaces, particu-
larly textile fabr~cs and fibers. As used herein, the
term 'substances having reactive surfaces" or "surface
reactive substratets) n is meant to include any material
whose surface is able to form covalent chemical bollds with
the didecylmethyl-substituted silyl quaternary ammonium
compounds of the invention. It has now been found that
these didecylmethyl substituted ammonium compounds more
effectively inhibit the growth of such microorganisms,
including, for example, both various gram-positive and
gram-negative bacteria, than their known adjacent homo-
logs.
While the specific site of action of the organo-
silicon quaternary ammonium compounds is still underinvestigation it is known that the compounas are chemi-
cally bonded to a variety of reactive surfaces and are not
removed therefrom by repeated leaching or ~ashing with
water. Thus, the compounds of the present invention are
useful to impart durable bioactive properties to surfaces
like natural and synthetic textile fibers, siliceous mate-
rials like glass, stone and ceramics; metals; and also,
leather, wood, plastic and the like. Generally, the sur-
face reactive materials are treated by contacting the same
with the bioactive compound, e.g., by either dipping,
spraying, padding, or brushing the compound of the yresent
~ invention onto the substrates either prior to infestation
by microorganisms to prevent the growth thereof, or after
: infestation to kill and to prevent new growth thereof.
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The compounds of the present invention are
active in solution as well as when applied to solid sur-
faces. The antimicrobial compounds may thus be employed
as the pure compounds, in aqueous solution or dispersion,
or in organic solvent media.
Preferably, the compounds of the present inven-
tion are dissolved in a suitable organic water miscible
solvent forming a solution containing about 50% of the
compound of the present invention as active ingredient.
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~est Mode For Carrying Out The Invention
In accordance with the present invention it has
been found that 3-(trimethoxysilyl)propyldidecylmethyl
ammonium salts exhibit antimicrobial properties which are
superior to those of their known adjacent homologs. Such
materials are thus useful for a variety of bactericidal,
fungicidal and the like applications for which the use of
silyl quaternary ammonium compounds has previously been
proposed.
The compounds of the present invention may be
prepared by known methods. Thus, the tertiary amine,
i.e.,didecylmethyl amine, is reacted with an appropriate
silane, e.g , 3-chloropropyltrimethoxysilane with or with-
o~t the presence of a suitable solvent such as methanol.
The alkylation reaction of the tertiary amine proceeds
smoothly resulting in the production of 3-(trimethoxy-
silyl)propyldidecylmethyl ammonium chloride. Of course,other silanes may be similarly reacted to form other qua-
ternary ammonium halides, e.g , the fluoride, bromide, or
iodide, within the scope of the invention. ~imilarly,
silanes incorporating sulfate or acetate anions may be
converted to the corresponding quaternary ammonium salts,
within the purview hereofO
Alternatively, the salts of the present inven-
tion may be prepared by reacting didecylamines with thetrimethoxysilylpropylhalide, sulfate,acetate or phosphate in the
presence of sodium methylate to yield the corresponding
tertiary amines which are subsequently methylated to form
the organosilicon quaternary ammonium salts. A further
method for preparing the compound of the present invention
includes the preparation of the allyldidecylamine,
followed by hydrosilylation thereof with trimethoxysilane
to produce 3-~didecylamino)propyltrimethoxysilane, which
- is then treated with an appropriate methyl halide to yield
the compound of-the present invention.
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The preferred compound, 3-~trimethoxy -
silyl)propyldidecylmethyl ammonium chloride, may directly
contact the surface of the material to be treated by
either spraying or brushing, or the surface reactive sub-
5 strate may be immersed in the pure antimicrobial compoundor in a solution thereof in an appropriate solvent.
Surface reactive materials or substrates to
which the compound of the invention can be chemically
bonded include siliceous materials and metallic surfaces.
Leather, wood, rubber and plastic have also been shown to
have reactive surfaces. Indeed, the preferred class of
substrates having reactive surfaces to which the compound
of the invention can readily bond comprises the natural
and synthetic textile fibers and the corresponding fabrics
thereof. Such natural fibers include cotton, wool, linen
and felt; similarly bondable synthetic fibers include
those comprised wholly of synthetic polymeric material
such as viscose, cellulose acetate or triacetate; or
nylons, polyether, vinyl polymers, including polyolefins,
acrylics and modacrylics or the like; or blends of such
materials with natural fibers.
Suitaole solvents in which the compound of the
invention may be dissolved for bactericidal, fungicidal or
similar applications include water and organic water mis-
cible solvents like alcohols, such as methanol, ethanoland butanol; methyl Cellosolve~Yand ethyl Cellosolve;
ketones, such as methylethyl ketone. For textile
treatment, solvents used in commercial dry cleaning
processes, such as hydrocarbons, chlorinated hydrocarbons,
ethers and benzene may alternatively be used.
As disclosed hereinabove, the active compound of
the present invention may be applied to a variety of surfaces
- by any suitable means. For example~ it is possible to
spray the antimicrobial compound into shoes to inhibit or
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prevent growth of microorganisms therein. The pure com-
pound or a solution thereof may also be applied to walls
to prevent mold and mildew, or may be added to fillers
used in paints to prepare paints with antimicrobial prop-
erties. For treating textiles, the compound may be dis-
persed in the solvents used in commercial dry cleaningprocesses and thus be readily brought into contact with
textiles to be treated. Alternatively, the active com-
pound may be applied to textile fabrics or fibers by
exhaustion techniques, involving the use of closed systems
in which the fibers or fabrics to be treated are immersed
in a treating bath under preferably slightly elevated tem-
perature conditions to effect absorption and fixation of
the bioactive compound on the textile fibers and thus
"exhaust" the same from the bath. Such techniques are
more fully described, for example, in my prior U.S. Patent
No. 3,788,803.
Another preferred method for applying the bioac-
tive compound of the present invention to fabrics or
textile fibers is by padding. The fabric to be treated
may be immersed in a trough or padder containing a solu-
tion of the antimicrobial compound. The concentration ofthe active ingredient in the solution is adjusted
depending upon the ability of the substrate to pick up the
antimicrobial compound from the bath. Of course, fin-
ishing agents such as a softening agent or the like may be
add~d to either the exhaustion or the padding bath.
Thus, in the preferred embodiments of the pre-
sent invention for applying the antimicrobial compound of
the invention to textile fibers or fabrics, the fibers or
fabrics are immersed in a bath containing the compound (in
pure or dissolved form) for a period of from about 3-5
- minutes to about 20-30 minutes at temperatures of from
about 25 to 95 C., and preferably from about 40 to
70C. The amount of bioactive compound thus bonded to the
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textile fibers may vary, depending on the solvent and the
particular structure of the textile employed. The active
ingredient may be applied in an amount of from about 0.1%
to 1.0~ by weight of a textile substrate. Upon removal
of the textile fibers from such an exhaustion or padding
bath, the treated material may be dried in accordance with
conventional practice in the art, thereafter woven,
knitted, or otherwise converted to piece goods (if treated
in fibrous form), and subjected to conventional finishing
operations.
In the following examples all parts and percent-
ages are by weight, and all temperatures in degrees
Celsius~ unless otherwise indicated.
Example 1 - Preparation of 3-(Trimeth ~ ~ro~y~didecyl-
methyl Ammonium Chloride
In a 12-liter 3-neck round bottom reaction flask
e~uipped with stirrer, thermometer and condenser was pla-
- ced 4746 grams (15.2 moles) of didec~methylamine and
3160.7 grams (15.9 moles) 3-chloropropyltrimethoxysilane.
The solution was stirred with heating at llO~C. under a
nitrogen atmosphere for 48 hours. The dark yellow/orange
liquid was then placed under vacuum (5 torr), and approxi-
mately 135 mls. residual 3-chloropropyltrimethoxysilane
was removed. The remaining product was then added slowly
to 7750 grams of methanol with stirring to produce a pro-
duct containing 50% active materialL
Reaction with other, appropriately substituted
propyltrimethoxysilanes gi~es other salts of the desired
silyl quaternary ammonium compound, e.g., the bromides or
iodides thereof.
Example 2 - Preparation of 3-(Trimethoxysilyl)Pro~yldidecylmethy~
_ _ _ _ _
Pmmonium Chloride In Methanol ~
- In a 2-liter single-neck preparation flask was
placed 804 grams (2.58 moles) of didecylmethylamine, 536.5
grams (2.7 moles) of 3-chloropropyltrimethoxysilane and
4500 grams anhydrous methanol. The reaction mixture was
stirred with heating to a gentle reflux under nitrogen for
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g _
48 hours. The reaction was cooled to 35C. and 890 grams
of anhydrous methanol was added. The resulting yel-
low/orange solution contained 50 wt. % active material.
Example 3 - Com~arison of Antibacterial Activity_~
3-~Trimethoxysilyl)pro~yldiaecylmeth
Ammonium Chloride With The Activity_Of
Other Di-Long _ ain Alkyl Substituted
_~ _ __
~ano Silicon Quaternary Ammonium
Compounds Against Gram Positive and Gram
Negative Bacterla
The activity of the compound of Example 1 was
compared with various higher and lower adjacent homologs
against a gram positive (Sta~ aureus ATCC 6538) and gram
negative ~Klebsiella pneumoniae ATCC 4352) strain.
10 ml of a 10% aqueous solution of each bacteri-
cide tested was prepared. Four serial dilutions were made
by pipeting 1 ml of each 10% solution into a 10 ml vol-
umetric flask and filling to the mark with water~ 0.1 ml
of each serial dilution was added to 9.9 ml of sterile
molten nutrient agar in tubes which were maintained at
47C. in a water bath. 0.1 ml of blank water was added to
9.9 ml of sterile molten nutrient agar to serve as a con-
trol. 0.1 ml aliquots of a 24 hour culture of each test
organism were pipeted into six sterile petri dishes pre-
viously labeled 1000, 100, 10 , 1 and 0.1 and controlorganism. The contents of each tube was then poured into
its respective petri dish, swirled and allowed to soli-
- dify. The petri dishes were incubated, inverted, for 48
hours at 37C. The results were as follows:
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TAsLE I
Gram Positive Organism Gram Negative Organism
Staph Aureus K. Pneumoniae
_
Compounds 100 ppm 1000 ppm100 ppm. 1000 p~
Example 1 NGl NG NG NG
Control A G2 NG G NG
Control B G G G G
Control C5 G G G G
] NG = No growth
2 G = Growth
3 = 3-(trimethoxysilyl)propyldioctylmethyl ammonium chloride
4 = 3-(trimethoxysilyl)propyldidodecylmethyl ammonium chloride
= 3-(trimethoxysilyl)propyldihexadecylmethyl ammonium
chloride.
The compound of Example 1 prevented growth of
the test bacteria at concentrations of 100 ppm of the test ~--
compound, while the higher and lower homo]ogs thereof were
unable to prevent bacteria growth at that concentration.
Example 4 Comparison of Antibacterial Activity of
3-(Trimethoxysilyl)propyl didecylmethyl
Ammonium Chloride With The Activity of
Mono- Long Chain Alkyl Substituted Organo-
Silicon Quaternary Ammonium Compounds
Aqainst Gram Positive and Gram Negative
-
~acteria.
The compound of Example 1 was also compared with
related compounds having only one long chain alkyl
radical. The test was conducted according to the
procedure of Example 1. The followin~q results were
obtained:
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TABLE II
Pseud.
CompoundsStaph aure~s K. pneumoniae E. coli aeruginosa
(ATCC 6528) (ATCC 4352)(ATCC 11229) (QM 1468)
(ppm) (ppm) (ppm) (ppm)
5 Example 1 100 100 ~ 4200 ~ 4200
Control ~6100 100 ~ 4200 ~ 4200
Control E 100 7 4200 ~ 4200 7 4200
6 3-(trimethoxysilyl)propyldecyldimethyl ammonium chloride0 7 3-(trimethoxysilyl)propyloctadecyl~imethyl ammoni~m chloride
commercially marketed as "Bioguar 9-5700" (~PA No. 3492-1)
by Dow Corning.
15 The activity of the compound of Example 1 was as
great as that of the mono- long chain substituted compound
Control D. The compound of Example 1 exhibited antimicro-
bial activity against the tested gram positive strain
similar to that of the commercial product (Control E), but
showed greater activity than the commercial product
against the tested gram negative strain Klebsiella
pneumoniae. ~hen the compounds of Example 1 and Control
E were applied to polyester fabric, similar results were
obtained against K. pneumoniae bacteria at concentrations
of 0.25 to 0.5% active ingredient by weight of fabric
while on 100% cotton faDric at concentration levels of
0.25 to 1.0% active ingredient by weight of fabric the
compound of Example 1 again exhibited greater activity
against K. pneumoniae than the commercial product (Control
E).
From the preceding it may be seen that in
accordance with the present invention new organosilicon
- quaternary ammmoni~m salts are provided which have - -
` improved bactericidal, fungicidal and similar-
antimicrobial activities, and which may be applied to a
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73
variety of surface active materials. It should be
understood that the preferred embodiments described above
are for illustrative purposes only and are not to be con-
strued as limiting the scope of the invention which is
S properly delineated in the appended claims.
