Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Having -c- – wherein x is chalcogen – bonded directly to...
Reexamination Certificate
2000-05-24
2002-09-10
Pryor, Alton (Department: 1616)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Having -c-, wherein x is chalcogen, bonded directly to...
Reexamination Certificate
active
06448279
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to wood preservative and waterproofing compositions containing an amine oxide and an isothiazolone.
BACKGROUND OF THE INVENTION
Isothiazolones are known to be effective as wood preservatives. Many isothiazolones, however, have low water solubility. As a result, solutions containing them often have two or more phases.
U.S. Pat. No. 5,536,305 provides compositions comprising (a) a water insoluble wood preservative compound, such as an isothiazolone; (b) a surfactant system consisting of one or more surfactants selected front the group consisting of sulfonated anionics, sulfonated anionics, sulfosuccinated anionics, quaternary ammonium cationics, and amphoterics; and (c) optionally non-polar organic solvents.
There is a continuing need for improved isothiazolone wood preservatives and waterproofing compositions which have only one phase.
SUMMARY OF THE INVENTION
Applicants have discovered that amine oxides enhance the performance of isothiazolones as wood preservatives and provide waterproofing properties. Amine oxides also aide in solubilizing isothiazolones into aqueous solutions. The present invention provides a composition comprising an amine oxide and an isothiazolone.
Another embodiment of the present invention is a method for preserving and/or waterproofing a wood substrate by contacting the wood substrate with the composition.
Yet another embodiment is an article comprising a wood substrate and the composition of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a composition comprising an amine oxide and an isothiazolone. The amine oxide enhances penetration of the isothiazolone into wood substrates and improves leach resistance. Furthermore, the amine oxides aide in solubilizing the isothiazolone in water. As a result, aqueous solutions containing isothiazolones and amine oxides may be formed which have only one phase. The compositions of the present invention also have low volatility.
The amine oxide may be a trialkylamine oxide; an N-alkylcyclicamine oxide; a dialkylpiperazine di-N-oxide; an alkyldi(poly(oxyalkylene))amine oxide; a dialkylbenzylamine oxide; a fatty acylamidopropyldimethylamine oxide; a diamine oxide; a triamine oxide; and any combination of any of the foregoing. Preferably, the amine oxide includes at least one C
8
-C
18
alkyl moiety.
Preferred trialkylamine oxides have the formula R
1
R
2
R
3
N→O, where R
1
is a linear, branched, cyclic or any combination thereof C
8
to C
40
saturated or unsaturated group; and R
2
and R
3
independently are linear, branched, or any combination thereof C
1
to C
40
saturated or unsaturated groups. R
1
, R
2
, and R
3
independently may be alkyl, alkenyl, or alkynyl groups. More preferably, R
1
is a linear, branched, cyclic or any combination thereof C
8
to C
22
saturated or unsaturated group, such as coco, hydrogenated tallow, soya, decyl, and hexadecyl; and R
2
and R
3
independently are linear, branched, or any combination thereof C
1
to C
22
saturated or unsaturated groups, such as coco, hydrogenated tallow, soya, decyl, and hexadecyl.
A preferred trialkylamine oxide is a dialkylmethylamine oxide having the formula R
1
R
2
CH
3
N→O, where R
1
and R
2
are defined as above. Another preferred trialkylamine oxide is an alkyldimethylamine oxide having the formula R
1
(CH
3
)
2
N→O, where R
1
is defined as above. More preferred alkyldimethylamine oxides have the formula R
19
(CH
3
)
2
N→O, where R
19
is a linear or branched C
8
-C
18
alkyl or alkenyl. Preferably, R
19
is a linear or branched C
8
-C
16
alkyl. Alkyldimetlylamine oxides are non-toxic and non-mutagenic surfactants. Suitable alkyldimethylamine oxides include, but are not limited to, a C
10
alkyldimethylamine oxide, a C
10
-C
14
alkyldimethylamine oxide, a C
12
-C
16
alkyldimethylamine oxide, a C
16
-C
18
alkyldimethylamine oxide, and any combination of any of the foregoing.
Preferred N-alkylcyclicamines oxide have the formula R
4
R
5
R
6
N→O where R
4
is defined as R
1
above and R
5
and R
6
are linked to form a cyclic group. The cyclic group typically contains from about 4 to about 10 carbon atoms and may optionally contain oxygen, sulfur, nitrogen, or any combination of any of the foregoing. More preferred alkylcyclicamine oxides include, but are not limited to, an alkylmorpholine N-oxide, a dialkylpiperazine di-N-oxide, and any combination of any of the foregoing.
Preferred alkylmorpholine N-oxides have the formula
where R
7
is defined as R
1
above.
Preferred dialkylpiperazine di-N-oxides have the formula
where R
8
is defined as R
1
above and R
9
is defined as R
2
above.
Preferred alkyldi(poly(oxyalkylene))amine oxides have the formula
where R
10
is defined as R
1
above; R
11
and R
12
independently are H or CH
3
; and m and n independently are integers from about 1 to about 10.
Preferred dialkylbenzylamine oxides have the formula R
13
R
14
R
15
N→O, where R
13
is defined as R
1
above; R
14
is defined as R
2
above; and R
15
is benzyl. More preferred dialkylbenzylamine oxides include, but are not limited to, alkylbenzylmethylamine oxides having the formula R
13
R
15
CH
3
N→O where R
13
and R
15
are defined as above.
Preferred fatty acylamidopropyldimethylamine oxides have the formula
where R
16
is defined as R
1
above.
Preferred diamine oxides have the formula
where R
17
is defined as R
1
above; and m is an integer from about 1 to about 10.
Preferred triamine oxides have the formula
where R
18
is defined as R
1
above; and m and n independently are integers from about 1 to about 10.
Long chain (C
16
or greater) amine oxides, such as hexadecylamine oxides and hydrogenated tallow amine oxides, are particularly preferable for imparting waterproofing properties to the composition. Short chain (C
14
and shorter) amine oxides aide in solubilizing the isothiazolone and long chain amine oxides.
A blend of long chain and short chain amine oxides is also contemplated in one embodiment of the present invention. For example, the composition may contain a mixture of C
16
-C
18
long chain amine oxides to impart waterproofing properties and C
10
-C
14
short chain amine oxides to solubilize the long chain amine oxides. The long chain amine oxides may be blended with the short chain amine oxides in a ratio of about from about 1:10 to 10:1 in order to yield a stable preservative solution. More preferably, the ratio ranges from about 1:1 to about 2:1.
Suitable isothiazolones include, but are not limited to, benzisothiazolone (such as 1,2-benzisotiiazolone), 4,5-dichloro-2-octyl-3(2H)-isothiazolone, 2-octyl-3(2H)-isothiazolone, 4,5-trimethylene-3(2H)-isothiazolone, and any combination of the foregoing. Preferred isothiazolones include, but are not limited to, 3-isothiazolones, such as those disclosed in U.S. Pat. Nos. 4,105,431 and 3,761,488, both of which are wherein incorporated by reference. The composition may include a solvent, such as water and water miscible solvents, including, but not limited to, alcohols, such as ethanol; glycols; esters; ethers; polyethers; and any combination of any of the foregoing. Preferably, the composition does not include xylene and more preferably does not include a solvent other than water.
The weight ratio of amine oxide to isothiazolone broadly ranges from about 100:1 to about 1:1 and preferably from about 50:1 to 5:1.
According to one embodiment of the invention, the composition in concentrated form contains broadly from about 5 to about 100%, preferably from about 10 to about 50%, and more preferably from about 20 to about 35% by weight of combined amine oxide and isothiazolone based upon 100% weight of total composition.
Use dilutions of the composition typically comprise a biocidally effective amount of isothiazolone and a preservative enhancing and/or waterproofing effective amount of the amine oxide. Use dilutions preferably comprise from about 0.1 to about 5.0% by weight of amine oxide and from about 0.005 to about 0.5% by weight of isothiazolone based u
Tseng Chuen-Ing
Walker Leigh
Lonza Inc.
Pryor Alton
LandOfFree
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