U.S. patent application number 14/958759 was filed with the patent office on 2016-06-30 for process for the co-encapsulation of biocidally active compounds in clay minerals functionalized by nitrogen compounds.
This patent application is currently assigned to Clariant S.A.. The applicant listed for this patent is Clariant S.A.. Invention is credited to Marcia Regina DA SILVA RIOS, Wagner Claudio DA SILVA, Antonio Pedro de OLIVEIRA FILHO, Karine FRAMESQUI RIGHI, Manlio GALLOTTI, Alexandra Paschoalin MENEZES.
Application Number | 20160183520 14/958759 |
Document ID | / |
Family ID | 44474969 |
Filed Date | 2016-06-30 |
United States Patent
Application |
20160183520 |
Kind Code |
A1 |
de OLIVEIRA FILHO; Antonio Pedro ;
et al. |
June 30, 2016 |
Process For The Co-Encapsulation Of Biocidally Active Compounds In
Clay Minerals Functionalized By Nitrogen Compounds
Abstract
This invention relates to a process for the co-encapsulation of
biocidally active ingredients in a clay mineral, the process
comprising the step of bringing the clay mineral into contact with
a biocidally active nitrogen compound that contains at least one
hydrocarbon group with 6 to 20 carbon atoms, and at the same time
or subsequently with at least one biocidally active compound
selected from the group consisting of
2-n-octyl-4-isothiazoline-3-one, 3-iodopropenylbutyl-carbamate and
tetrahis(hydroxymethyl)phosphonium sulfate. And the use of such
encapsulated product in water based paints, coatings and
varnishes.
Inventors: |
de OLIVEIRA FILHO; Antonio
Pedro; (Sao Paulo, BR) ; DA SILVA; Wagner
Claudio; (Sao Paulo, BR) ; GALLOTTI; Manlio;
(Sao Paulo, BR) ; MENEZES; Alexandra Paschoalin;
(Sao Paulo, BR) ; FRAMESQUI RIGHI; Karine; (Sao
Paulo, BR) ; DA SILVA RIOS; Marcia Regina; (Sao
Paulo, BR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Clariant S.A. |
Sao Paulo |
|
BR |
|
|
Assignee: |
Clariant S.A.
Sao Paulo
BR
|
Family ID: |
44474969 |
Appl. No.: |
14/958759 |
Filed: |
December 3, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13580546 |
Aug 22, 2012 |
9228121 |
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PCT/EP2011/000683 |
Feb 15, 2011 |
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14958759 |
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Current U.S.
Class: |
424/417 ;
106/18.31; 106/18.32; 106/18.33; 514/372; 514/479 |
Current CPC
Class: |
C09D 5/14 20130101; A01N
25/08 20130101; C08K 3/346 20130101; C09D 7/62 20180101; A01N 43/80
20130101; A01N 33/08 20130101; A01N 57/34 20130101; A01N 33/04
20130101; A01N 33/12 20130101; A01N 25/26 20130101; C09K 8/03
20130101; A01N 47/12 20130101; C08K 9/04 20130101; A01N 33/04
20130101; A01N 25/08 20130101; A01N 25/12 20130101; A01N 43/80
20130101; A01N 47/12 20130101; A01N 57/34 20130101; A01N 59/16
20130101; A01N 33/08 20130101; A01N 25/08 20130101; A01N 25/12
20130101; A01N 43/80 20130101; A01N 47/12 20130101; A01N 57/34
20130101; A01N 59/16 20130101; A01N 33/12 20130101; A01N 25/08
20130101; A01N 25/12 20130101; A01N 43/80 20130101; A01N 47/12
20130101; A01N 57/34 20130101; A01N 59/16 20130101; A01N 43/80
20130101; A01N 25/08 20130101; A01N 25/12 20130101; A01N 59/16
20130101; A01N 47/12 20130101; A01N 25/08 20130101; A01N 25/12
20130101; A01N 57/34 20130101; A01N 25/08 20130101; A01N 25/12
20130101; A01N 33/04 20130101; A01N 2300/00 20130101; A01N 33/08
20130101; A01N 2300/00 20130101; A01N 33/12 20130101; A01N 2300/00
20130101; A01N 43/80 20130101; A01N 2300/00 20130101; A01N 47/12
20130101; A01N 2300/00 20130101; A01N 57/34 20130101; A01N 2300/00
20130101 |
International
Class: |
A01N 25/26 20060101
A01N025/26; C09D 5/14 20060101 C09D005/14; A01N 43/80 20060101
A01N043/80; A01N 25/08 20060101 A01N025/08; A01N 33/12 20060101
A01N033/12; A01N 47/12 20060101 A01N047/12 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2010 |
EP |
10001837.3 |
Dec 24, 2010 |
EP |
10016075.3 |
Claims
1.-16. (canceled)
17. A biocidally active clay mineral comprising biocidally active
nitrogen compound having at least one hydrocarbon group with 6 to
20 carbon atoms and at least one of 2-n-octyl-4-isothiazoline-3-one
(OIT), 3-iodopropenylbutylcarbamate (IPBC) and
tetrakis(hydroxymethyl)phosphonium-sulfate (THPS) encapsulated in a
clay mineral.
18. A water based paint, coating or varnish, comprising a
biocidally active clay mineral, prepared by bringing a clay mineral
into contact with a biocidally active nitrogen compound that
contains at least one hydrocarbon group with 6 to 20 carbon atoms,
and at the same time or subsequently bringing the clay mineral into
contact with at least one biocidally active compound selected from
the group consisting of 2-n-octyl-4-isothiazoline-3-one (OIT),
3-iodopropenylbutylcarbamate (IPBC) and
tetrakis(hydroxymethyl)phosphonium-sulfate (THPS).
19. (canceled)
20. The biocidally active clay mineral according to claim 17,
wherein the clay mineral further comprises at least one smectite
group mineral in a concentration ranging between 60-95 wt.-%,
relative to the total weight of the clay mineral.
21. The biocidally active clay mineral according to claim 17,
wherein the biocidally active nitrogen compound is a quaternary
ammonium compound according to the formula
[R.sup.1R.sup.2R.sup.3R.sup.4N].sup.+X.sup.- (1) wherein R.sup.1,
R.sup.2, R.sup.3, and R.sup.4 independently are linear, branched,
cyclic, saturated or unsaturated hydrocarbon groups containing
between 1 and 30 carbon atoms, and X is an anion, with the proviso
that at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 contains
at least 6 and at most 20 carbon atoms.
22. The biocidally active clay mineral according to claim 21,
wherein the sum of the number of carbon atoms in R.sup.1, R.sup.2,
R.sup.3, and R.sup.4 ranges from 9 to 30.
23. The biocidally active clay mineral according to claim 17,
wherein the biocidally active nitrogen compound is an alkylamine of
the formula [R.sup.1R.sup.2R.sup.3N] (7) wherein R.sup.1, R.sup.2
and R.sup.3 independently are hydrogen, linear or branched
C.sub.6-C.sub.20 saturated or unsaturated hydrocarbon groups.
24. The biocidally active clay mineral according to claim 17,
wherein the biocidally active nitrogen compound is an etheramine of
the formula ##STR00007## or an etheramine salt corresponding to of
the formula ##STR00008## wherein R.sup.1 is
(C.sub.2-C.sub.30)-alkyl or C.sub.5- to C.sub.12-cycloalkyl,
R.sup.2 is H, CH.sub.3, CH.sub.2CH.sub.3 or
(CH.sub.2).sub.2CH.sub.3, n is 1, 2, 3, 4 or 5, and X is an anion
such that the etheramine is water soluble.
25. The biocidally active clay mineral according to claim 17,
wherein the biocidally active nitrogen compound is an ether diamine
of the formula ##STR00009## or an etherdiamine salt of the formula
##STR00010## wherein for both formula 10a and 10b R.sup.1 is
(C.sub.2-C.sub.30)-alkyl or C.sub.5- to C.sub.12-cycloalkyl;
R.sup.2, R.sup.3 are H, CH.sub.3, CH.sub.2CH.sub.3 or
(CH.sub.2).sub.2CH.sub.3, n, o are 1, 2, 3, 4 or 5 and X is an
anion such that the etheramine compound is water soluble.
26. The biocidally active clay mineral according to claim 17,
wherein the biocidally active nitrogen compound is a sternamine of
the formula ##STR00011## wherein R.sup.1 is
(C.sub.2-C.sub.30)-alkyl or C.sub.5- to C.sub.12-cycloalkyl;
R.sup.5 corresponds to the formula ##STR00012## R.sup.2, R.sup.3,
R.sup.4, R.sup.6 are H, CH.sub.3, CH.sub.2CH.sub.3 or
(CH.sub.2).sub.2CH.sub.3, n, o, p, q are 1, 2, 3, 4 or 5, or a salt
obtainable from the compounds of formula 11 by protonation of the
free NH.sub.2 groups.
26. The biocidally active clay mineral according to claim 17,
further comprising a further biocidally active compound, into
contact with the clay mineral, wherein the further biocidally
active compound is selected from the group consisting of Ethanol,
1-Propanol, 2-Propanol, 1,2-Propanediol, 2-Phenoxyethanol,
1-Phenoxypropanol, Formaldehyde, Glutaraldehyde, Acetaldehyde,
Glyoxal, Ethylene Glycol hemiformal, Ethylene Glycol bishemiformal,
1,3-dioxolane, 3,3'-Methylenebis(5-methyl-1,3-oxazolidine),
Hexahydro-1,3,5-tris(2-hydroxyethyl)-s-triazine,
Hexahydro-1,3,5-tris(2-hydroxypropyl)-s-triazine,
Bis(tetrakis(hydroxymethyl)phosphonium)sulfate,
1,3-Bis(hydroxymethyl)5,5-dimethyl-2,4-dioxoimidazolidine),
6-Acetoxy-2,4-dimethyl-1,3-dioxane, 2,5-Dimethoxytetrahydrofuran,
Phenol, Chloromethylphenol, 4-Chlorophenol, Formic acid, Acetic
acid, sorbic acid, benzoic acid, boric acid, Ethyl formate, Benzyl
bromoacetate, dimethyl dicarbonate,
N'-(3,4-dichlorophenyl)-N,N-dimethylurea,
N'-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea),
3-lodopropynylphenylcarbamate, 3-lodopropynylcarbamate,
Methyl-N-(2-benzimidazolyl)carbamate, 4,4'-Diamidinophenoxypropane,
4,4'-Diamidino-2,2'-dibromodiphenoxypropane, Pyridine-N-oxides,
8-Quinolinol,
1-[2-(2,4-Dichlorophenyl)-4-propyl-1,3-dioxolan-2yl-methyl]1H-1,2,4-triaz-
ole, 2-methyl-4-isothiazolin-3-one,
5-Chloro-2-methyl-4-isothiazolin-3-one,
4,5-dichloro-2-(n-octyl)4-isothiazolin-3-one,
1,2-benzisothiazolin-3-one, N-butyl-1,2-benzisothiazolin-3-one),
N,N,dimethyl-N'-tolyl-N'-dichlorofluromythylthiosulphamide,
2-Bromoacetamide, 2,2-Dibromo-3-nitrilopropionamide,
2-bromo-2-nitro-propan-1-ol, 2-bromo-2-nitropro-pane-1,3-diol,
poly(hexamethylenebiguanide) hydrochloride, sodium ethylmercury
thiosalicylate, trichloromelamine and
1,3-dichloro-5,5-dimethylhydantoin.
27. The biocidally active clay mineral according to claim 17,
further comprising the step of bringing a metal ion into contact
with the clay mineral, wherein the metal ion is selected from the
group consisting of silver, copper, zinc, molybdenum and titanium
ions.
28. The biocidally active clay mineral according to claim 17,
wherein the combined amount of a) the biocidally active nitrogen
compound that contains at least one hydrocarbon group with 6 to 20
carbon atoms and b) any other biocidally active compounds in the
finished biocidally active clay mineral is from 1 to 60 wt.-%,
relative to the weight of the finished biocidally active clay
mineral.
29. The biocidally active clay mineral according to claim 17,
wherein the weight ratio between the biocidally active compound and
the biocidally active nitrogen compound that contains at least one
hydrocarbon group with 6 to 20 carbon atoms is in the range of 1:10
to 10:1.
30. The biocidally active clay mineral according to claim 27,
wherein the total amount of the metal ions, is between 0.5 and 21
wt.-%, the wt.-% being relative to the combined weight of a) the
biocidally active nitrogen compound that contains at least one
hydrocarbon group with 6 to 20 carbon atoms and b) the metal ions,
and, c) any other biocidally active compounds.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a process for the co-encapsulation
of biocidally active compounds in clay minerals which are
functionalized by hydrocarbon-substituted nitrogen compounds. A
preferred embodiment of this invention is the use of
hydrocarbon-substituted nitrogen compounds as vehicle to carry on
the active ingredient inside the layers of the clay mineral. The
process makes it possible to encapsulate a large quantity and a
variety of active ingredients inside layers of a clay mineral.
BACKGROUND OF THE INVENTION
[0002] The process of production of clay minerals having a
lipophilic characteristic ("organoclays") using ammonium quaternary
salts to give to clay minerals said lipophilic characteristic is
known. Clay minerals, especially smectite, are a class of minerals
that contain in their structural formula dioctahedral aluminous
species which can be represented by the formula
[(Al.sub.(2-y)Mg.sub.y)(Si.sub.(4-x)Al.sub.x)O.sub.10(OH).sub.2][M.sub.(-
x+y)]nH.sub.2O
wherein: [0003] x is the amount of aluminum atoms exchangeable from
octahedral sheet, and [0004] y is the amount of silicon atoms
exchangeable from tetrahedral sheet, and [0005] M.sub.(x+y) are
monovalent cations present in the clay structure to compensate the
resultant charge after the exchange of aluminum and silicon have
occurred into the octahedral and tetrahedral sheets,
respectively.
[0006] Regarding the total amount of cation exchangeable capacity,
(x+y) comprises the range 0.2.ltoreq.(x+y).ltoreq.0.6. This range
represents the minimum and maximum milliequivalents of cation
exchangeable in 100 g of clay mineral.
[0007] U.S. Pat. No. 2,531,427 discloses that if M.sub.(x+y) is
exchanged by an ammonium quaternary salt two different effects are
observed in the clay mineral. The replacement of the cation by the
ammonium quaternary salt causes an enlargement of the distance
between layers of the clay mineral, and the clay mineral surface
becomes hydrophobic because of the presence of the alkyl groups
introduced by the ammonium quaternary salt. The objective of that
invention was to provide a modification of the clay mineral by
replacing the interlayer cation by amines in order to give to the
clay mineral surface a substantial gelling characteristic which
swelled when dispersed in an organic liquid.
[0008] Further state of the art is summarized as follows.
[0009] U.S. Pat. No. 3,467,208 discloses the application of
bentonite treated by long-chain amines in order to give good
thixotropy for an oil based drilling mud and to avoid the fluid
loss during the well drilling process.
[0010] U.S. Pat. No. 3,831,678 discloses the use of a clay which
has been organically functionalized by dimethyltallow hydrogenated
ammonium salts as viscosifier in oil based drilling fluids.
[0011] U.S. Pat. No. 4,752,342 teaches a process for the
replacement of sodium by an ammonium quaternary salt in a clay
mineral.
[0012] The state of the art presented above does not present any
disclosure about encapsulation or co-encapsulation of biocidally
active ingredients interlayer of the clay minerals. It discloses
the preparation of organophilic clays with several types of amines
and ammonium quaternary salts.
[0013] U.S. Pat. No. 5,164,096 discloses the use of biocide
contained within the core of the microcapsules made of a gum
gelatin membrane. These microcapsules are used to treat a water
system by controlled release of the biocide actives.
[0014] WO-A-93/02668 discloses the microencapsulation of at least
one active ingredient, contained in an hydrophilic internal core,
coated by a coat of copolymer of ethylene and vinyl acetate (EVA)
or a copolymer of vinylidene chloride and vinyl chloride and other
types of polymers.
[0015] U.S. Pat. No. 6,165,485 discloses that a bentonite based
organoclay, when mixed with a biocidal quaternary amine containing
a benzyl molecule within its structure, acts as a reasonably
effective biocide.
[0016] U.S. Pat. No. 6,521,678 describes a method for preparing
organoclays with a substantially monomolecular layer of water
soluble polymer to the clay; applying a surfactant to the clay to
modify the hydrophilic/hydrophobic balance of surfaces of the clay
and separate out the organoclay from the water.
[0017] U.S. Pat. No. 7,429,392 discloses the use of biocides bonded
to solid resins particles in order to confer antimicrobial
protection to highly alkaline coating films, e.g. paints, leading
to higher stability in the pH of the paint and delayed release of
the biocide.
[0018] It has been observed that there are biocidally active
ingredients that cannot be encapsulated into organophilic clay
using the encapsulation modifiers of the state of the art. The
problem of the instant invention was to find an encapsulation
modifier that allows such biocidally active ingredients to be
encapsulated in a clay mineral.
[0019] It has been found that the use of clay mineral
functionalized by hydrocarbon-substituted nitrogen compounds allows
co-encapsulation of several types of biocidally active ingredients
which otherwise can not be inserted into the interlayer of the clay
mineral without the presence of the hydrocarbon-substituted
nitrogen compounds.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The instant invention relates to a process for the
co-encapsulation of biocidally active ingredients in a clay
mineral, the process comprising the step of bringing the clay
mineral into contact with a biocidally active nitrogen compound
that contains at least one hydrocarbon group with 6 to 20 carbon
atoms, and at the same time or subsequently with at least one
biocidally active compound selected from the group consisting of
2-n-octyl-4-isothiazoline-3-one, 3-iodopropenylbutyl-carbamate and
tetrakis(hydroxymethyl)phosphonium sulfate.
[0021] Another object of the invention is a biocidally active clay
mineral, obtainable by bringing the clay mineral into contact with
a nitrogen compound that contains at least one hydrocarbon group
with 6 to 20 carbon atoms, and at the same time or subsequently
with at least one biocidally active compound selected from the
group consisting of 2-n-octyl-4-isothiazoline-3-one (OIT),
3-iodopropenylbutylcarbamate (IPBC) and
tetrakis(hydroxymethyl)phosphoniumsulfate (THPS).
[0022] Another object of the invention is the use of a biocidally
active nitrogen compound having at least one hydrocarbon group with
6 to 20 carbon atoms to encapsulate a biocidal composition, said
composition comprising at least one of OIT, IPBC and THPS, in a
clay mineral.
[0023] The expressions "actives" or "active ingredients" as used
herein refer to biocidally active compounds. The expression
"biocidally active" means that the respective compound is capable
of killing microorganisms or preventing the growth of
microorganisms (bacteriostatic) which can spoil or contaminate a
raw material or product. Microorganisms are for example bacteria,
fungi and algae.
[0024] Preferably, the clay minerals comprise smectite group
mineral in a concentration ranging between 60-95 wt.-%.
Additionally, minerals like quartz, cristobalite, feldspar, pirite,
carbonates, chlorite, caolinite, mica and illite may be present.
The preferred mineral species from the smectite group mineral are
beidellite, hectorite, montmorillonite, nontronite, sauconite,
saponite and volconscoite. The structural formula of smectites of
the dioctahedral aluminous species may be represented by
[(Al.sub.(2-y)Mg.sub.y)(Si.sub.(4-x)Al.sub.x)O.sub.10(OH).sub.2][M.sub.(-
x+y)]nH.sub.2O
wherein: x is the amount of aluminum atoms exchangeable from
octahedral sheet, and y is the amount of silicon atoms exchangeable
from tetrahedral sheet, and M.sub.(x+y) are monovalent cations
present in the clay structure to compensate the resultant charge
after the exchange of aluminum and silicon have occurred into the
octahedral and tetrahedral sheets, respectively.
[0025] Regarding the total amount of cation exchangeable capacity,
(x+y) comprises the range 0.2.ltoreq.(x+y).ltoreq.0.6. This range
represents the minimum and maximum milliequivalents of cation
exchangeable in 100 g of clay mineral. n is the molar amount of
water present in the clay mineral, which can take values from 0 to
7, preferably 2 to 6.
[0026] Usually, clay minerals from the smectite group are also
known as bentonites.
[0027] The biocidally active nitrogen compound may be chosen from a
variety of generic groups. Common to all of the following formulae
and the definition of the residues is the requirement that at least
one of the residues is a hydrocarbyl residue having at least 6 and
at most 20 carbon atoms.
[0028] In one preferred embodiment, the nitrogen compound is a
quaternary ammonium compound. Preferred quaternary ammonium
compounds correspond to the formula
[R.sup.1R.sup.2R.sup.3R.sup.4N].sup.+X.sup.- (1)
wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 independently are
linear, branched, cyclic, saturated or unsaturated hydrocarbon
groups, and X is an anion. R.sup.1, R.sup.2, R.sup.3 and R.sup.4
may contain between 1 and 30 carbon atoms, provided that at least
one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 contains from 6 to 20
carbon atoms. The sum of the number of carbon atoms in R.sup.1,
R.sup.2, R.sup.3, and R.sup.4 preferably ranges from 9 to 30.
R.sup.1, R.sup.2, R.sup.3, and R.sup.4 may be alkyl, alkenyl,
alkynyl, cycloalkyl or aryl groups. X may be chloride, carbonate,
bicarbonate, nitrate, bromide, acetate or carboxylates.
[0029] A preferred quaternary ammonium compound corresponds to the
formula
[R.sup.1(CH.sub.3).sub.3N].sup.+X.sup.- (2)
wherein R.sup.1 is a linear or branched C.sub.6-C.sub.20 saturated
or unsaturated hydrocarbon group, such as an alkyl, alkenyl, or
alkynyl group and X is defined as above. More preferably, R.sup.1
is a linear C.sub.6-C.sub.18 saturated or unsaturated group and X
is chloride, carbonate, or acetate.
[0030] Another preferred quaternary ammonium compound corresponds
to the formula
[R.sup.1R.sup.2(CH.sub.3).sub.2N].sup.+X.sup.- (3)
wherein R.sup.1 is a linear or branched C.sub.6-C.sub.20 saturated
or unsaturated hydrocarbon group or C.sub.6-C.sub.20 substituted,
benzyl or unsubstituted aryl group, R.sup.2 is a linear or branched
C.sub.1-C.sub.20 saturated or unsaturated group or C.sub.6-C.sub.20
substituted, benzyl or unsubstituted aryl group, and X is defined
as above. Preferably, R.sup.1 and R.sup.2 independently are linear
or branched C.sub.8-C.sub.16 saturated or unsaturated groups. In a
more preferred embodiment, R.sup.1 and R.sup.2 independently are
linear or branched C.sub.8-C.sub.12 saturated or unsaturated groups
and X is chloride, carbonate, sulfate, or acetate.
[0031] The expression substituted as used herein means substitution
with a C.sub.1-C.sub.4 alkyl group.
[0032] Another preferred quaternary ammonium compound corresponds
to the formula
[R.sup.1R.sup.2(CH.sub.3).sub.2N].sup.+X.sup.- (4)
wherein R.sup.1 is a substituted or unsubstituted benzyl group,
R.sup.2 is a linear C.sub.10 to C.sub.20 saturated or unsaturated
hydrocarbon group, and X is defined as above.
[0033] According to a preferred embodiment, R.sup.1 is benzyl,
R.sup.2 is a linear C.sub.12-C.sub.18 saturated or unsaturated
hydrocarbon group, and X.sup.- is chloride.
[0034] Another quaternary ammonium compound preferred for use in
the present invention corresponds to the formula
[R.sup.1R.sup.2N(CH.sub.3)((CH.sub.2CH.sub.2O).sub.nH)].sup.+X.sup.-
(5)
wherein R.sup.1 is a C.sub.6-C.sub.20 linear or branched,
substituted or unsubstituted alkyl group or a C.sub.6-C.sub.20
substituted or unsubstituted aryl group, R.sup.2 is a
C.sub.1-C.sub.20 linear or branched, substituted or unsubstituted
alkyl group or a C.sub.6-C.sub.20 substituted or unsubstituted aryl
group, n is an integer from 1 to 5, and X is defined as above.
Preferably, R.sup.1 and R.sup.2 are linear or branched
C.sub.8-C.sub.10 substituted or unsubstituted alkyl or aryl groups
and more preferably are decyl. X.sup.- is preferably chloride.
[0035] Another preferred quaternary ammonium compound corresponds
to the formula
[R.sup.1R.sup.2R.sup.3(CH.sub.3)N].sup.+X.sup.- (6)
wherein R.sup.1, R.sup.2 and R.sup.3 independently are linear or
branched C.sub.6-C.sub.20 saturated or unsaturated groups. More
preferably R.sup.1, R.sup.2 and R.sup.3 independently are linear or
branched C.sub.8-C.sub.10 saturated or unsaturated groups. X is
preferably chloride.
[0036] One, two or more of quaternary ammonium compounds can be
used to produce an organoclay system which is the vehicle to the
active ingredients, i.e. into which the active ingredients are
co-encapsulated.
[0037] In cases wherein X.sup.- means an ion with a charge of more
than one, e.g. a carbonate or sulfate ion, its stoichiometric index
is to be divided by the charge in order to achieve electric
neutrality.
[0038] Apart from said ammonium compounds, nitrogen containing
compounds comprising at least one hydrocarbon group with 6 to 20
carbon atoms that do not necessarily carry a charge may be used
according to the instant invention.
[0039] Examples of such nitrogen containing compounds are alkyl
amines, amines, ether diamines and sternamines.
[0040] A preferred alkylamine has the formula
[R.sup.1R.sup.2R.sup.3N] (7)
wherein R.sup.1, R.sup.2 and R.sup.3 independently are hydrogen,
linear or branched C.sub.6-C.sub.20 saturated or unsaturated
hydrocarbon groups. More preferably R.sup.1, R.sup.2 and R.sup.3
independently are linear or branched C.sub.8-C.sub.10 saturated or
unsaturated groups. The saturated or unsaturated groups are more
preferably alkyl groups, alkenyl groups or cycloalkyl groups having
6 to 20 carbon atoms.
[0041] A preferred etheramine corresponds to the generic
formula
##STR00001##
wherein R.sup.1 is (C.sub.2-C.sub.30)-alkyl or C.sub.5- to
C.sub.12-cycloalkyl; R.sup.2 is H, CH.sub.3, CH.sub.2CH.sub.3 or
(CH.sub.2).sub.2CH.sub.3, n is 1, 2, 3, 4 or 5
[0042] Apart from the etheramines, their salts may be used.
Suitable etheramine salts are represented by the generic
formula
##STR00002##
wherein R.sup.1 is (C.sub.2-C.sub.30)-alkyl or C.sub.5- to
C.sub.12-cycloalkyl; R.sup.2 is H, CH.sub.3, CH.sub.2CH.sub.3 or
(CH.sub.2).sub.2CH.sub.3, n is 1, 2, 3, 4 or 5 and
[0043] X is an anion such that the etheramines compound is water
soluble.
[0044] The use of ether amine salts according to formula 9 is
preferred over the use of ether amines according to formula 8.
Ether amine salts according to formula 9 show superior permeation
ability into the layers of the clay mineral.
[0045] A preferred ether diamine corresponds to the generic
formula
##STR00003##
[0046] Again, the salts of such ether diamines may be used in this
invention. Preferred salts correspond to the formula
##STR00004##
wherein for both formula 10a and 10b R.sup.1 is
(C.sub.2-C.sub.30)-alkyl or C.sub.5- to C.sub.12-cycloalkyl;
R.sup.2, R.sup.3 are H, CH.sub.3, CH.sub.2CH.sub.3 or
(CH.sub.2).sub.2CH.sub.3, n, o are 1, 2, 3, 4 or 5 and X is an
anion such that the etheramine compound is water soluble.
[0047] Sternamines and their salts also can be used as vehicle in
order to co-encapsulate active substances or metal with biocide
activity. A suitable sternamine corresponds to the generic
formula
##STR00005##
wherein R.sup.1 is (C.sub.2-C.sub.30)-alkyl or C.sub.5- to
C.sub.12-cycloalkyl; R.sup.5 corresponds to the formula
##STR00006##
R.sup.2, R.sup.3, R.sup.4, R.sup.6 are H, CH.sub.3,
CH.sub.2CH.sub.3 or (CH.sub.2).sub.2CH.sub.3, n, o, p, q are 1, 2,
3, 4 or 5.
[0048] Again, the salts obtainable from the compounds of formula 11
by protonation of the free NH.sub.2 groups may also be used in this
invention.
[0049] Common to all of formulae 8-12 is that R.sup.1 is preferably
an alkyl or cycloalkyl group having 6 to 20 carbon atoms,
particularly 8 to 16 carbon atoms. The cycloalkyl group may be
bicyclic, tricyclic or higher.
[0050] The biocidally active compound has to comprise at least one
of OIT, IPBC and THPS. It may contain any binary combination of
these compounds, e.g. OIT and IPBC, OIT and THPS, IPBC and THPS,
OIT and THPS and the ternary combination of OIT, IPBC and THPS.
[0051] Preferably, in order to obtain multifunctional synergistic
compositions, at least one other biocidally active compound which
is different from a nitrogen compound that contains at least one
hydrocarbon group with 6 to 20 carbon atoms, or
2-n-octyl-4-isothiazoline-3-one (OIT), 3-iodopropenylbutylcarbamate
(IPBC) and tetrakis(hydroxymethyl)phosphoniumsulfate (THPS) is
present.
[0052] A suitable active ingredient is a substance that contains in
its structure one or more functional groups which give to the
molecule biocidally activity. Preferred generic classes of active
ingredients are etheramines, amines, phenols and its derivates;
aldehydes; formaldehyde releasing compounds; acetaldehyde releasing
compounds; succinaldehyde releasing compounds; 2-propenaldehyde
releasing compounds; acids; acid esters; amides; carbamates;
dibenzamides; pyridine derivatives; azoles; N compounds; S
heterocyclics; N-Haloalkylthio compounds; compounds containing
activated halogen atom; surface activation agents; organometallic
compounds; and oxidizing agents.
[0053] Examples of these active ingredients are: Ethanol,
1-Propanol, 2-Propanol, 1,2-Propanediol, 2-Phenoxyethanol,
1-Phenoxypropanol, Formaldehyde, Glutaraldehyde, Acetaldehyde,
Glyoxal, Ethylene Glycol hemiformal, Ethylene Glycol bishemiformal,
1,3-dioxolane, 3,3'-Methylenebis(5-methyl-1,3-oxazolidine),
Hexahydro-1,3,5-tris(2-hydroxyethyl)-s-triazine,
Hexahydro-1,3,5-tris(2-hydroxypropyl)-s-triazine,
Bis(tetrakis(hydroxymethyl)phosphonium)sulfate,
1,3-Bis(hydroxymethyl)5,5-dimethyl-2,4-dioxoimidazolidine),
6-Acetoxy-2,4-dimethyl-1,3-dioxane, 2,5-Dimethoxytetrahydrofuran,
Phenol, Chloromethylphenol, 4-Chlorophenol, Formic acid, Acetic
acid, sorbic acid, benzoic acid, boric acid, Ethyl formate, Benzyl
bromoacetate, dimethyl dicarbonate,
N'-(3,4-dichlorophenyl)-N,N-dimethylurea,
N'-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea),
3-lodopropynylphenylcarbamate, 3-lodopropynylcarbamate,
Methyl-N-(2-benzimidazolyl)carbamate, 4,4'-Diamidinophenoxypropane,
4,4'-Diamidino-2,2'-dibromodiphenoxypropane, Pyridine-N-oxides,
8-Quinolinol,
1-[2-(2,4-Dichlorophenyl)-4-propyl-1,3-dioxolan-2yl-methyl]1H-1,2,4-triaz-
ole, 2-methyl-4-isothiazolin-3-one,
5-Chloro-2-methyl-4-isothiazolin-3-one,
4,5-dichloro-2-(n-octyl)4-isothiazolin-3-one,
1,2-benzisothiazolin-3-one, N-butyl-1,2-benzisothiazolin-3-one),
N,N,dimethyl-N'-tolyl-N'-dichlorofluromythylthiosulphamide,
2-Bromoacetamide, 2,2-Dibromo-3-nitrilopropionamide,
2-bromo-2-nitro-propan-1-ol, 2-bromo-2-nitropro-pane-1,3-diol,
poly(hexamethylenebiguanide) hydrochloride, sodium ethylmercury
thiosalicylate, trichloromelamine and
1,3-dichloro-5,5-dimethylhydantoin.
[0054] Metallic ions which have a biocidal property may also be
employed as further components. They are preferably employed for
surface modification of the clay mineral. The following metallic
ions are preferred: silver, copper, zinc, molybdenum and
titanium.
[0055] The combined amount of all biocides, i.e. nitrogen compound
that contains at least one hydrocarbon group with 6 to 20 carbon
atoms and OIT, IPBC or THPS or their mixture, and, if present metal
ions, and, if present one or more any other biocidally active
compound which is different from a nitrogen compound that contains
at least one hydrocarbon group with 6 to 20 carbon atoms, or
2-n-octyl-4-isothiazoline-3-one (OIT), 3-iodopropenylbutylcarbamate
(IPBC) and tetrakis(hydroxymethyl)phosphoniumsulfate (THPS) in the
finished biocidally active clay mineral is preferably from 1 to 60,
particularly from 5 to 55, more preferably from 10 to 45 wt.-%,
relative to the weight of the finished biocidally active clay
mineral.
[0056] The weight ratio between OIT, IPBC or THPS or their mixture
and the nitrogen compound that contains at least one hydrocarbon
group with 6 to 20 carbon atoms is preferably in the range of 1:10
to 10:1, particularly 1:5 to 5:1, more preferably 1:2 to 2:1 by
weight.
[0057] In the embodiment wherein the finished biocidally active
clay mineral contains metal ions, one or more any other biocidally
active compound, or both, the total amount of the metal ions, if
present, is preferably between 0.5 and 21 wt.-%, particularly
between 8 and 13 wt.-%, the wt.-% being relative to the combined
amount of all biocides, including the metal ions.
[0058] In the embodiment wherein the finished biocidally active
clay mineral contains metal ions, one or more any other biocidally
active compound, or both, the total amount of one or more any other
biocidally active compound which is different from a nitrogen
compound that contains at least one hydrocarbon group with 6 to 20
carbon atoms, or 2-n-octyl-4-isothiazoline-3-one (OIT),
3-iodopropenylbutylcarbamate (IPBC) and
tetrakis(hydroxymethyl)phosphoniumsulfate (THPS) is preferably
between 0.5 and 21 wt.-%, particularly between 8 and 13 wt.-%, the
wt.-% being relative to the combined amount of all biocides,
including the other biocidally active compound.
[0059] Compounds according to the instant invention are useful for
application in agriculture, oil industry, as biocide to varnishes,
paints, coatings, mortars, grouts and in corrosion inhibitor
compositions.
[0060] The compounds according to the instant invention when used
in paints, varnishes and coating materials are capable of showing
their biocidal activity even in case of exposition of the paints,
varnishes and coating materials to a damp environment or water.
[0061] The consequence of microbiological infestation by fungus and
algae is normally the presence of spots on the surface. As well as
disfiguring the surface, the organisms can actually penetrate the
paints, varnishes and coating materials and make them more
permeable to water. Growth can also develop under the paints,
varnishes and coating materials and cause loss of adhesion.
[0062] Commonly, fungus and algae growth are favored by bacterial
infestation, which can lead to a pH decrease due to the excretion
of acid compounds by said microorganisms. Differently from typical
fungi and algae infestation, bacterial growth is not perceived
visually, then being an important factor for general
microbiological infestation.
[0063] It has been known that besides the use of bactericidal
agents required for in can preservation of paints, varnishes and
coatings, fungicidal and/or algicidal as well as bactericides are
also added in order to preserve the films formed by paints,
varnishes and coatings. Generally, the use of biocidally active
agents is recommended for all kinds of paints, coatings and
varnishes, but they are of paramount importance for critical
environments.
[0064] The main problem related to the use of biocides in paints,
coatings and varnishes is leaching. Water soluble biocides may
leach to the environment when exposed to a damp environment or
water, what, depending on the weathering situation, leads to poor
effectiveness in short periods of time and infestation of films by
microorganisms, therefore requiring a new surface treatment.
[0065] Besides the leaching problem, the high toxicity of many
commercially available biocidally active agents is of great concern
for producers of paints, varnishes and coatings, thus safer
biocidally active agents of low toxicity to the environment and to
the human beings are required.
[0066] Common biocidally active agents such as heterocyclic
compounds, carbamates, halogenated compounds, amides and trazines,
shows among other problems, a tendency to change their colour to
yellow and to degrade under high temperatures and the influence of
light, these effects limiting their use.
[0067] The state of the art in paints, coatings and varnishes
preservation is the association of different biocidally active
agents and the use of encapsulated biocidally active agents in
polymeric material carriers, for control of microbiological growth.
The encapsulation technology has been used for different
applications in order to deliver toxicological, stability and
time-effectiveness benefits.
[0068] The controlled release of biocidally active agents is
important when there is immediate consumption of the biocidally
active agent upon its application, reducing the need of a new
application, and adding a preservative characteristic to the
biocidally active agent. When a product requires bacteriostatic
action, the controlled release increases that product's shelf
life.
[0069] One embodiment of the present invention relates to the use
of the compounds according to the instant invention in paints,
varnishes and coatings, including marine applications. The use of
the compounds according to the instant invention in such
applications is effective in preventing microbial growth even in
damp environments.
[0070] Some properties of the compounds according to the instant
invention include, but are not limited to: higher UV radiation
stability; higher thermal stability; controlled release of
biocides; high biocide effectiveness as function of time; reduced
toxicity and higher environmental compatibility.
[0071] In contrast to the prior art, the use of clay minerals as
carriers is significantly less expensive than the use of polymeric
resins. Moreover, the nitrogen compounds used for functionalization
of the clay mineral which are also effective as algicide and not
commonly used in paints, coatings and varnishes, are significantly
less toxic than typically used algicidal molecules, such as
N,N-t-butyl-N,N,N,N-ethyl-6-methylthio-1,3,5-triazine-2,4-diyldiamine
(terbutryn) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea
(diuron).
[0072] The preferred total amount of the encapsulated biocide in
the paint, coating or varnish varies from 0.01% to 10% by weight of
the treated paint, coating or varnish.
[0073] The biocide encapsulating process includes an inorganic
material as encapsulating agent and biocide components. A paint,
coating or varnish containing the encapsulated biocide has
antimicrobial properties and low biocide leaching compared to
non-encapsulated biocide treated paint, coating or varnish.
[0074] The encapsulating clay mineral particles work as biocide
molecules inert carriers. The encapsulating process aims at
improving interaction properties, i.e. polar and hydrophilic
biocides absorption by plasmatic membrane adding hydrophobic
characteristics to the biocide compound.
[0075] Another particularity of the use of such encapsulated
biocides may be a slight modification of rheological properties of
water based paints, coatings and varnishes, related to the presence
of clay minerals.
[0076] Other embodiments of the present invention are water based
paints, coatings and varnishes which comprises the encapsulated
biocide and a binder.
[0077] Paints are coatings which contain solid pigments dispersed
in a liquid vehicle intended for application on different surfaces.
The pigment may be inorganic or organic. Examples of inorganic
pigments are titanium dioxide, zinc oxide, chromium oxide, iron
oxide, carbon black and combinations thereof. Organic pigments can
include, for instance, phthalocyanines, azo-compounds,
quinacridones, perylenes and others. The vehicle typically contains
a binder and a solvent. In case of water based paints the solvent
is water. Suitable binders are latex, vinyls, acrylics, alkyds and
combinations thereof.
[0078] Usually water based paints includes other additives such as
dispersants, surfactants, wetting agents, defoamers, driers,
extenders, rheology modifiers and coalescent agents.
[0079] Varnishes are glossy, transparent coatings mainly used for
application on wood, containing a binder and a vehicle. In one
embodiment of this invention the use of encapsulated biocides is in
water based varnishes, in which the solvent is water. Typical
examples of binders used in varnishes are latex, vinyls, acrylics
and alkyds.
[0080] Usually water based varnishes includes other additives such
as dispersants, surfactants, wetting agents, defoamers, driers,
rheology modifiers and coalescent agents.
[0081] The following examples of compositions were prepared
according to examples 1 to 4 described in this patent and
illustrate the invention without limiting it thereto. All amounts
are given as weight % (w/w).
EXAMPLES
Example 1
Preparation of Smectite Organoclay
[0082] Smectite organophilic clays are synthesized from the sodium
form of bentonite. First of all 380 g of water is added in a beaker
and 20 g of sodium bentonite is slowly added under mechanical
stirring and stirred for 20 minutes. Under mechanical stirring 9.13
g of Dodigen.RTM. 2808 (benzalkonium chloride) is added and stirred
for 60 minutes. The dispersion is left standing at room temperature
for 24 hours, after which it is filtered through a buchner funnel.
The solid filtered materials are dried at 60.degree. C. for 48
hours and then ground and sieved through a 100 mesh (0.149 mm)
sieve.
Example 2
Co-Encapsulation of IPBC Inside of Organoclay
[0083] Co-encapsulated IPBC inside of organoclay is synthesized
from the sodium form of bentonite. First of all 380 g of water is
added in a beaker and 20 g of sodium bentonite is slowly added
under mechanical stirring and stirred for 20 minutes. Under
mechanical stirring 9.13 g of Dodigen.RTM. 2808 (benzalkonium
chloride) is added and stirred for 60 minutes. After 5.62 g of
Nipacide.RTM. IPBC (3-lodopropynylbutylcarbamate) is added and
stirred for more 60 minutes. The dispersion is left standing at
room temperature for 24 hours, after which it is filtered through a
buchner funnel. The solid filtered materials are dried at
60.degree. C. for 48 hours and then ground and sieved through a 100
mesh (0.149 mm) sieve.
Example 3
Co-Encapsulation of OIT Inside of Organoclay
[0084] Co-encapsulation of OIT inside of organoclay is synthesized
from the sodium form of bentonite. First of all 380 g of water is
added in a beaker and 20 g of sodium bentonite is slowly added
under mechanical stirring and stirred for 20 minutes. Under
mechanical stirring 9.13 g of Dodigen.RTM. 2808 (benzalkonium
chloride) is added and stirred for 60 minutes. After 9.47 g of
Nipacide.RTM. OIT (2-n-octyl-4-isothiazolin-3-one) is added and
stirred for more 60 minutes. The dispersion is left standing at
room temperature for 24 hours, after which it is filtered through a
buchner funnel. The solid filtered materials are dried at
60.degree. C. for 48 hours and then ground and sieved through a 100
mesh (0.149 mm) sieve.
Example 4
Metal Modified Clay Minerals
[0085] Metal modified clay mineral is synthesized from the sodium
form of bentonite. First of all 380 g of water is added in a beaker
and 20 g of sodium bentonite is slowly added under mechanical
stirring and stirred for 20 minutes. Under mechanical stirring 4.00
g of Dodigen.RTM. 2808 (benzalkonium chloride) is added and stirred
for 60 minutes. After 3.11 g of Nipacide.RTM. OIT
(2-n-octyl-4-isothiazolin-3-one) is added and stirred for more 60
minutes. Finally 1.60 g of Silver nitrate is added and stirred for
more 60 minutes. The dispersion is left standing at room
temperature for 24 hours, after which it is filtered through a
buchner funnel. The solid filtered materials are dried at
60.degree. C. for 48 hours and then ground and sieved through a 100
mesh (0.149 mm) sieve.
Analytical Data
[0086] The instant process is using the lipophilic chain of the
ammonium quaternary salts as a vehicle to carry on the active
ingredients into the layers of the clay minerals. By using this
technique it is possible to insert into clay minerals actives
without exchanging the sodium of the clay mineral. The process of
co-encapsulation of the active ingredients can be shown by X-Ray
analysis. After the active ingredient has been encapsulated, a
metal with biocidal activity can also be added to the layers of the
clay minerals.
[0087] Our results using X-Ray analysis show that basal distance
between the layers of two tetrahedral sheets condensed with one
octahedral sheet in the sodium bentonite form is 14.72 .ANG.. After
the encapsulation with benzalkonium chloride (Dodigen.TM. 2808)
this basal distance rise up to two diffractions 17.65 .ANG. and
25.21 .ANG.. These two different distances are due the different
chain lengths present in the benzalkonium chloride, the first one
(17.65 .ANG.) from C.sub.12/14 chain length and the second one
25.21 .ANG. from C.sub.16/18 chain.
[0088] The X-ray analysis also was used to show the
co-encapsulation of IPBC in a clay mineral previously
functionalized with benzalkonium chloride (Dodigen.RTM. 2808) as
described in Example 2. This co-encapsulation of IPBC was observed
with basal distances rising from 17.65 .ANG. to 70.60 .ANG.
corresponding to the interaction of C.sub.12-C.sub.14 chains from
benzalkonium chloride and IPBC molecules. Simultaneously, an
interaction of C.sub.16-C.sub.18 chains from benzalkonium chloride
and IPBC molecules occurs. This interaction results in a reduction
of basal distance from 25.21 .ANG. to 16.05 .ANG. due to the low
concentration of C.sub.16-18 benzalkonium compounds and because
rearrangements occurring between IPBC molecules and the C.sub.16-18
benzalkonium chain during drying of the product. These alterations
of the basal distances show the presence of IPBC co-encapsulated
into the clay previously functionalized with benzalkonium chloride
(Dodigen.RTM. 2808). Another proof of the co-encapsulation of IPBC
is available by Scanning Electron Microscopy (SEM) coupled with an
Energy Dispersive X-ray Detector (EDS). This method presents a peak
around 3.9 keV showing the presence of iodine which came from IPBC.
The basal distance of 70.60 .ANG. is equivalent to 7.06 nm showing
that IPBC is nanometrically scattered into the clay previously
functionalized.
[0089] Other analysis methods such as thermogravimetrical analysis
(TG) showed in sodium bentonite a mass loss around 10.6% below
100.degree. C. due to mainly water present in the clay. Considering
the TG analysis of ammonium quaternary salts encapsulated, the
result shows a mass loss of 10.6% of quaternary ammonium salt used
in the process. The same results were found when IPBC was
co-encapsulated into the clay previously functionalized.
[0090] The same behaviour was observed when
2-n-octyl-4-isothiazolin-3-one (OIT) was co-encapsulated. After the
co-encapsulation of OIT, silver was anchored into the hydrophobic
surface composed of tetra-alkylammonium quaternary salt and OIT.
Silver in this case complexes with the nitrogen and sulfur atoms
presents in OIT molecules. The complex from silver and OIT is not
susceptible to oxidation of silver.
Example 5
Synergism
[0091] In order to show the synergism achieved when working the
instant invention, benzalkonium chloride and a biocide were
encapsulated into a clay mineral. The efficiency of the so obtained
composition was determined using the algae contamination avoidance
test according to ASTM D5589-97 (2002). The shown concentrations
are the minimum concentrations required to prevent algae
contamination.
TABLE-US-00001 TABLE 1 Minimum Inhibitory Concentration based on
active ingredient encapsulated alone and active ingredients
co-encapsulated into clay mineral against fungi contamination on
dry film (Norm NBR 14941-2003). Active Ingredients [ppm]
benzalkonium Products IPBC chloride Encapsulated benzalkonium
chloride (BKC) -- >2000 Encapsulated IPBC 1000 -- IPBC
co-encapsulated in organoclay 500 600 functionalized with
benzalkonium chloride
[0092] The synergistic effect can be calculated by synergistic
index (SI), according to the following formula (F. C. Kull et al.,
Applied Microbiology, vol. 9 (1961), p. 538):
SI=Qa/QA+Qb/QB
Wherein:
[0093] Qa--concentration (in ppm) of IPBC, in combination with BKC,
which produced good results against fungi/algae growth.
QA--concentration (in ppm) of IPBC, as a single biocide, which
produced good results against fungi/algae growth. Qb--concentration
(in ppm) of BKC, in combination with IPBC, which produced good
results against fungi/algae growth. QB--concentration (in ppm) of
BKC, as single biocide, which produced good results against
fungi/algae growth.
[0094] A synergistic index<1 corresponds to a synergistic
effect. The minimal inhibitory concentration may be regarded as
good result. In this example, the SI equals 0.8.
Example 6
[0095] A standard water based architectural paint formulation
containing the following ingredients was made:
TABLE-US-00002 TABLE 2 Composition of the paint formulation % by
weight Water 35.83 Rheological additive (Acrylic associative
thickener) 0.40 Titanium dioxide 8.00 Calcium carbonate, 325 mesh
18.00 Talc, 325 mesh 7.00 Calcium carbonate precipitated 10.00
Aluminum silicate 6.00 Ammonia 0.10 Sodium Nitrite 0.07 Defoamer
(D-Foam-R C113, Clariant) 0.20 Polyacrylate (Dispersol 589,
Clariant) 0.80 Dioctyl sulfosuccinate (Wetting agent B 70,
Clariant) 0.10 Rheological additive (Acrylic associative thickener)
1.50 Butylglycol 0.70 Texanol .RTM., Eastman 0.30 Styrene-acrylate
copolymer dispersion 11.00
[0096] The viscosity of the paint was adjusted with water to 90 KU
(Krebs units, measured using the Krebs viscosimeter and spindle at
200 rpm) and the pH with ammonia solution or water to 9.0.
[0097] The encapsulated biocide, as described in example 2, was
added to the paint during the grinding or let down phase, the
encapsulates containing a bentonite,
C.sub.12/C.sub.14-alkyldimethyl benzyl ammonium chloride, and
3-iodopropenylbutylcarbamate.
Example 7
[0098] Test specimens were prepared by application of two paint
coats on watercolor paper (160 g/cm.sup.2) for each biocidal
composition. After application, test specimens were dried during 7
days. After drying, coated substrates were cut in 30 mm
squares.
[0099] The test specimens were evaluated after a leaching test
where the coated substrates were leached for 8 and 24 hours in 2 L
containers of water with a flow rate such that there are 6 changes
of the water in a period of 24 hours. Coated substrates were dried
to room temperature for 48 hours and then evaluated in terms of
microbiological effectiveness.
[0100] For the evaluation of antifungal performance on dry film the
following test was used:
[0101] Sabouraud dextrose agar medium was inoculated with isolated
fungi species (Aspergius niger ATCC 6275, Alternaria alternate ATCC
20084, Cladosporium cladosporioides ATCC 16022) in order to have a
final concentration of 10.sup.3 UFC/mL and poured on plates. For
each biocidal composition and microorganism, the test was done
three times.
[0102] The test specimens were placed on the center of the plate
and incubated at 27.degree. C. for 14 days. The fungal growth on
the sample surface was evaluated using the following scale:
0--No growth visible 1--Up to 10% surface coverage 2--10 to 25%
surface coverage 3--25 to 50% surface coverage 4--51 to 75% surface
coverage 5--More than 75% surface coverage
TABLE-US-00003 TABLE 3 Fungal growth test C. A. niger A. alternate
cladosporioides ATCC ATCC ATCC 6275 20084 16022 Control (without
biocide) 555 555 555 1500 ppm of IPBC 455 255 554
3-iodopropenylbutylcarbamate Nipacide .RTM. IPBC 10 2000 ppm of
IPBC 111 000 211 3-iodopropenylbutylcarbamate Nipacide .RTM. IPBC
10 500 ppm of IPBC in 555 444 333 Encapsulated Biocide of Example 2
1000 ppm of IPBC in 000 000 000 Encapsulated Biocide of Example
2
[0103] It can be seen from this table that the addition of the
encapsulated biocide of Example 2 in an amount that caused 1000 ppm
of IPBC to be present was sufficient to prevent fungal growth. This
effect cannot even be obtained by the addition of neat IPBC in an
amount of 2000 ppm.
[0104] The algicidal effect on dry film was evaluated as described
bellow:
[0105] Inoculums were prepared with a suspension of algae species
(Trentepohlia odorata, Chlorella sp and Scenedesmus quadricauda) at
concentration of 10.sup.6 cells/mL. Coated substrates were placed
on the center of a pre-poured Bold's Basal Medium agar plates. A
thin coat of the algae suspension was applied over the plates.
Plates were incubated with humidity .gtoreq.85%, 25.degree. C. and
cycle of 12 hours light and 12 hours darkness. For each biocidal
composition the test was done three times.
[0106] The algae growth on the sample surface was evaluated weekly
for 3 weeks using the following scale:
0--No growth visible 1--Up to 10% surface coverage 2--10 to 30%
surface coverage 3--30 to 60% surface coverage 4--More than 60%
surface coverage
TABLE-US-00004 TABLE 4 Algae growth test Algae suspension Control
(without biocide) 444 1500 ppm of BKC 444
C.sub.12/C.sub.14-alkyldimethyl benzyl ammonium chloride, Dodigen
.RTM. 2808 2000 ppm of BKC 333 C.sub.12/C.sub.14-alkyldimethyl
benzyl ammonium chloride, Dodigen .RTM. 2808 1000 ppm of BKC in 432
Encapsulated Biocide of Example 2 1500 ppm of BKC in 000
Encapsulated Biocide of Example 2
[0107] It can be seen from this table that the addition of the
encapsulated biocide of Example 2 in an amount that caused 1500 ppm
of BKC to be present was sufficient to prevent algae growth. This
effect cannot nearly be obtained by the addition of neat BKC in an
amount of 2000 ppm.
TABLE-US-00005 TABLE 5 Conclusion of microbiological test results
after leaching: Effective concentration against fungi Effective
concentration (ppm relatively against algae (ppm to the paint)
relatively to the paint) 3-iodopropenylbutylcarbamate >2000 ppm
of na Nipacide .RTM. IPBC 10 IPBC C.sub.12/C.sub.14-alkyldimethyl
benzyl na >>2000 ppm of BKC ammonium chloride, Dodigen .RTM.
2808 Encapsulated Biocide of 1000 ppm of 1500 ppm of BKC Example 2
IPBC *na = not analysed
Example 8
[0108] Additionally, the leaching of biocides was evaluated through
a tray test in which 50 g of the a paint formulation containing
1000 ppm of biocidally active agent was applied in the bottom of a
tray (23.5.times.38.0 cm) each time and the painting procedure was
repeated twice. The film was dried at room temperature for seven
days and then 500 mL of distilled water was added to the tray,
after 1, 3, 6 and 24 hours a 10 mL sample were taken and analyzed
for determination of the biocides.
TABLE-US-00006 TABLE 6 Tray test analysis results
C.sub.12/C.sub.14-alkyldimethyl benzyl ammonium chloride, Dodigen
.RTM. 2808 Encapsulated Biocide 1 hour 164 ppm <50 ppm 3 hours
177 ppm <50 ppm 6 hours 190 ppm <50 ppm 24 hours 224 ppm
<50 ppm Method's detection limit = 50 ppm
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