Note: Descriptions are shown in the official language in which they were submitted.
2 ~ 2 ~
- 1 -
PRESERVATIVE COMPOSITIONS
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Field of the Invention
The present invention relatss to preservative
containing compositions for uso in household and
industrial products.
~; 5
~ackaround o~ the In~en~ion
A variety of preservative agent~ havs been
~ formulated into compositions that are marketed as
;; household products such as cleaners, floor polishes,
0 painta, stains, cosmetics, personal care products and
industrial fluids such as metal working, secondary oil
recovery, cooling tower, and pulp and paper procQssing
composition~.
It is an object of the present invention to
increase the dispersibility of these agents in aqueous
media while minimizing or eliminating the need for
organic solvent~.
Summarv of the Invention
The present invention is directed to a
preservative composition that comprises an aqueous
dispersion of particles of at least one preservative
wherein said particles have a surface modifier adsorbed
on the surface thereof in an amount sufficient to
achieve a particle size of less than about 400
nanometers (nm). The compositions of tha present
`, invention can contain other conventional ingredients
that are used in such compositions.
,~
; 30 Detailed ~escriDtio~ of the Invention
The compositions of the invention comprise
.~
; preservative containing nanoparticles. The preservative
can be any of a variety of compounds such a~ glycerol,
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monolaurate, parabens, pyrthione~, and insoluble
guaternary amine complexes.
The particles of this invention contain a
; discrete phas~ of a pre~ervative a described abovehaving a RurfacQ modifier adsorbed on the sur~ace
thereo~. Use~ul surface modifiers are believed to
include those which physically adhere to the sur~ace o~
the preservativ~ but do not chemically bond to the
~ preservative.
3 lo Suitable surface modifiers can preferably be
~J selected from known organic and inorganic excipient~.
~i Such excipients lnclude various polymers, low molecular
weight oligomers, natural products and sur~actants.
Preferred surface modifiers include nonionic and anionic
surfactants. Representative examples o~ excipients
include gelatin, casein, lecithin (phosphatides), gum
acacia, cholesterol, tragacanth, stearic acid,
benzalkonium chloride, calcium stearate, glyceryl
~ monostearate, cetostearl alcohol, cetomacrogol
;~ 20 emulsifying wax, sorbitan esters, polyoxyethylene alkyl
ethers, e.g., macrogol ethers such as cetomacrogol 1000,
polyoxyethylene castor oil derivatives, polyoxyethylene
sorbitan fatty acid esters~ e.g., the commercially
availabl~ Tweens, polyethylene glycols, polyoxyethylene
stearates, colloidol silicon dioxide, phosphates, odium
dodecylsulfate, carboxymethylcellulose calcium,
carboxymethylcellulose sodium, methylcellulose
hydroxyethylcellulose, hydroxypropylcellulose,
`~ hydroxypropylmethycellulose phthalate, noncrystalline
cellulo3e, magnesium aluminum silicate, triethanolamine,
polyvinyl alcohol, and polyvinylpyrrolidone (PVP). Most
o~ these excipients ara described in detail in the
Handbook of Pharmaceutical Excipients, published jointly
by the American Pharmaceutical Association and The
~ 35 Pharmaceutical Society o~ Great Britain, the
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; 2 ~ 2
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',3, Pharmaceutical Press, 1986, the disclosure o~ which is~, here~y incorporated by re~erence in it5 entirety. The
surfacQ modi~iers are commercially available and/or can
b~ prepared by techniques known in the art.
` 5 The surface modifier is adsorbed on the
-1, surface o~ the preservative in an amount sufficient to
maintain an effective averag~ particle ~ize of less than
about 400 nm. The sur~ace modifier does not chemically
react with the preservative or itsel~. Furthermore, the
individually adsorbed molecules of the sur~ac~ modi~ier
are essentially free of intermolecular crosslinkages.
As used herein, particle siz~ refers to a
number averag~ particle size as measured by conventional
particle size measuring techniques well known to those
skilled in the art, such as sedimentation field flow
fractionation, photon correlation spectroscopy, or disk
centrifugation. By "an effectiv4 average particle size
of les~ than about 400 nm" it is meant that at least 90%
of the particles have a weight average particle size of
les~ than about 400 nm when measured by the above-noted
techniques. In preferred embodiments of the invention,
the effeçtive average particle size is less than about
250 nm. In some embodiments of the invention, an
effective averag~ particle size of less than about 100
nm has been achieved. With reference to the effectiv~
average particl~ size, it is preferred that at least 95%
and, more preferably, at least 99% o~ the particle~ hav~
-~ a particle size less than the effective average, e.g.,
400 nm. In particu~arly pre~erred embodiments,
.~
essentially all of the particles have a size les than
400 nm. In some embodiments, essentially all of the
particles have a size less than 250 n~.
The particles of this invention can be
prepared by a method comprising the steps of dispersing
.~i , .
~i 35 a preservative in a liquid dispersion medium and
.
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`~; applyin~ mechanical mean~ in the prQsence o~ grinding
~`''!'' media to reduco th~ particle 8iZR 0~ the in~ction
-i control agent to an effective avQrage particle size of
~, le88 than about 400 nm. The particle~ can be reduced in
size in the presenc~ o~ ~ surfacQ modi~ier.
~lternatively, th~ particle~ can bQ contacted with a
surface modifi~r ~fter attrition.
These mQthods are described in detail in U.S.
Patent No. 5,145,684.
The relative amount o~ preservativ~ and
~urface modi~ier can vary widely and thQ optimal amount
o~ the surface modifier can depend, for exampl~, upon
the particular preservative and sur~ac~ modi~ier
; selected, the critical micelle concentrat~on of the
surface modifier if it ~orm8 micellQs, etc. The surfaca
modifier prefer~bly i~ present in an amount of about
0.1-~0 mg per ~guare meter surface ~rea of the
:~ halohydanto~n. The surfaco modifiQr can be present in
an amount of 0.1-99.995%, preferably 20-60% by weight
based on the total weight of the formulation.
m e nanoparticles of th~ present invention can
be incorporated into conventional preserving and
s~ microbiocidQ compositions, a3 ~or exampl~, thos~
disclosed in U.S. Patent Nos. 4,040,977; 4,379,137;
4,996,052 and S,023,267, th~ disclosure~ o~ which are
incorporated herein. Additives such as perfumes,
anticorrosivQ agent Q.g., benzotriazole, fungicides,
biocide~ and other similar additives can b~ incorporated
~ in thesQ compositions.
-, 30 Representativ~ preservative~ lnclud~ a thiol~n
1 of the formul~:
,` ,~
~j'' x~o
,
--1
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;; ",
:., . ~ .
: ,~, , : : :,
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;-- wherein each o~ X and Y, which may b~ the ~ame or
~ di~ferent represents fluorin~, chlorine or bromine, an
'3'',,~ alXylenebisthiocyanat~ and a 2-N-alky1-4-isothiazolin-3-
`'-'~1
on~;
~ compound sQlected from the group con~isting
o~ polymeric quaternary a~monium compound~ having the
formula:
Rs-hO-CUI-A-cH~ ~ hO-Z-NO-CH~-A-CH~ R~.(2~+2)X~
~h~--Z--l'JO--CH2--A--CHI~ .2nX~
wherein Rl and R2, which can b~ tho same or differ~nt
are alkyl having from 1 to 20 carbon atoms an~ having
r"~ 20 from 0 to 1 hydroxyl substituent, benzyl, benzyl bearing
on the benzene moiety one alkyl having from 2 to 20
~ carbon a~oms; h~, R4 and R5, which can be th~ oam~ or- di~ferent, ar~ alkyl having ~rom 1 to 20 carbon atoms
and having from 0 to 1 hydroxyl substituent, or R3 and
- 25 R~ taken together with th~ nitrogen to which they are
~ attached ~orm a ~aturat~d het2rocyclic ring having from
.ii 5 to 7 ring ato~s; Z and A, which can be the same or
different, are divalent alkylen~ radicals o~ 2 to 10
carbon atom~ interrupted by from 0 to 1 oxygen atom and
containing ~rom 0 to 2 ethylenic double bonds; n i3 a
whols number ~rom 2 to 30; and X i~ ~ halogen; and
;:~
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~'
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.~ .... .
2 3
~ 6 -
- ..
a 3-i~othiazolone having the ~ormul~:
R'~N--Y
;
wherein Y i8 ~lkyl having from 1 to 18 carbon atoms,
. cyclohexyl, phenyl, halophenyl, benzyl or halobenzyl,
and R', which can b~ the same or different, ar~
hydrogen, halogen, ~lXyl having from 1 to 6 carbon
~;~!; atom~, alkenyl o~ 2 to 6 carbon atoms or phenyl, or R
.~. and R' togeth~r with the carbon atom3 to which they are
,~.'r att~ched form a benzene ring, or a salt thereof with
~trong acid, or a 3-isothiazolone metal salt complex
~: 15 having the formula:
,:
~a [ s ' Yl (Ml~",)
. 20
. wherein Y, R and R' are a~ de~ined above, M is a cation
, o~ calcium or magnesium, B i~ a chloride anion or
.~ nitrate anion, a i3 the whole number 1 or 2, and ~ i~
the nu~ber 2: wherein the ratio of component (a) to
component ~b) is ~rom 1:200 to 200:1: and
phosphate derivative~ o~ the following general
`; formula:
,,
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~.~. U
3 0 X ' ~ OR
OH
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- wherein:
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. ,G. ,' ' ~ :
2 i
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,.......................................................................... .
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R may be alkyl, aryl, aralkyl and alkaryl
group~ including, but not limited to, straight chain,
branched chain or cyclic alkyl groups having fro~ 1 to
24 carbon atoms, polyoxyethylene or polyoxypropylene
having from 2 to 32 ethylene oxide or propylene oxide
units respectively, alkyl phenoxy polyoxyethylene
containing 2 to 32 ethyleno oxide unit~, alkyl phenoxy
polyoxyethylen~ containing ethylene oxide units and 1 to
24 carbon atoms in the phenolic alkyl chain, and
polyhydroxy compounds, including but not limited to,
3 ethylene glycol, ylycerol or sorbitol.
X is selectQd from the group consisting of
Group IA metals, Group IIA metals, tr~nsition metals,
hydrogen and an organic ion. The positively charged ion
is not necessary for microbiocidal activity.
Th~ compositions of the present invention can
be illustrated by the following representative example.
Example 1
Preservative Floor Polish
Ingredient Wt. %
Water 47
Nanoparticle preservatives0.01 - 1
Premixed plasticizer
(Tributoxyethyl Phosphate) 1.2
`~ Diethylene glycol monomethyl ether 5.0
1% FC-129 ~olution 0.5
Texanol 0.34
Methyl Pyrolidone 0.55
Acrylic Polymer 33
Rosin Ester 3.3
Polyethylene Emulsion 8.2
The foregoing specification, including tho
specific embodiments and example i8 intended to be
illustrative of the present invention and is not to be
taken a~ limiting. Numerous other variation~ and
modifications can be effected without departing from the
true spirit and scope of the present invention.
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