Paper making and fiber liberation – Processes and products – Non-fiber additive
Reexamination Certificate
2000-04-05
2002-08-06
Chin, Peter (Department: 1731)
Paper making and fiber liberation
Processes and products
Non-fiber additive
16, C210S764000
Reexamination Certificate
active
06428654
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the use of strobilurin antifungal agents, and to antifungals for use in industrial process waters, such as in the pulp and paper industries.
2. Discussion of Background
In many applications, such as industrial applications including the paper industry and in cooling towers, it is important to prevent or retard the growth of organisms, such as fungi, mildew, algae, protozoa and bacteria, in water or aqueous fluids. Biocides, e.g., fungicides, are used for this purpose. Fungicides, however, tend to be poorly water soluble, and so require special compositions for application in an intended use.
Fungicides are also important in industry in the area of wet-lap preservation. The term “wet-lap” refers to paper or other cellulosic product that is not completely dried after manufacture. Wet-lap is produced when paper destined for further processing may be maintained in a wet state until the further processing can begin. Where wet-lap is to be kept wet for an extended period, e.g., several days or more, the wet-lap can become subject to fungal or other biological attack. It is important, therefore, to preserve wet-lap by, e.g., application of an appropriate biocide, e.g., application of an antifungal composition.
Organic solvents used for fungicides in, e.g., in papermaking, can be noxious, volatile, flammable, and subject to regulation by governmental authorities. Fungicides such as Amical 48 (a formulation of diiodomethyl-paratolylsulfone) for example, are available in benzothiazole or in heavy aromatic naphtha.
Strobilurins form a class of biocides that is widely used in agriculture as crop protectants. The first strobilurins identified, strobilurins A and B, were isolated from the basidomycete
Strobilurus tenacellus
and
Crepidotus fulvotomentosus
. These antifungal compounds, which function by inhibiting mitochondrial respiration, were found to be quite efficacious as crop protectants in controlling numerous species of nuisance and pathogenic fungi, yet they exhibit low mammalian toxicity.
Because strobilurins have low solubility in water, they are commercially available as clay dispersions or microparticulate suspensions for application on crops, produce, and other agricultural products. For example, in U.S. Pat. No. 5,021,581, which is herein incorporated by reference in its entirety, there are disclosed strobilurin compositions comprising clay or talc in Examples 17-21. The document also discloses, in Example 16, a strobilurin composition comprising benzyl alcohol, calcium dodecylbenzene sulphonate, nonylphenolethoxylate, and alkyl benzenes.
Despite the wide range of biocidal activity exhibited by strobilurins, however, strobilurins have had limited use outside the agricultural arena. It is believed that the only use for strobilurins outside the agricultural arena has been limited use as a human and veterinary antifungal in a topical formulation. In particular, a strobilurin product has been used in a human and veterinary antifungal product under the name MUCIDERMIN SPOFA.
While strobilurin fungicides for use in agricultural settings, as noted above, can be formulated as clay or talc dispersions, in industrial settings, e.g., in process water systems, it is generally believed that fungicides for industrial use should be in the form of a solution rather than a dispersion. For this reason, among others, people outside the agricultural field would not look to agricultural fungicides.
Further, the presence of clay or talc is avoided in process water systems, e.g., in paper machines, because of the effects that such substances can have on machinery and product produced. In the case of paper machines, for example, the quantity and quality of clay and/or talc added, if any, is tightly controlled because these components can affect the quality of the paper product. Yet further, in cooling towers and heat exchangers, it is typically believed that clay or talc could present potential problems, e.g., clogging and abrasion of machine parts.
Fungicide compositions for use in a process water system, e.g., a paper machine or cooling tower, therefore, are generally formulated, as noted above, in organic solvents rather than as dispersions with, e.g., clay or talc.
Because of toxicity, volatility, and environmental concerns associated with fungicides formulated in volatile organic compounds, there is a need for safer fungicides and fungicide formulations for use in industry, such as in paper making, heat exchangers and cooling towers.
There is a need for biocidal compositions, e.g., antifungal compositions, for use in process water and/or process water systems, such as pulp and paper applications, and water cooling systems. There is also a need for biocidal methods, e.g., antifungal methods, for use in such systems.
There is a need for new antifungal methods for use in industrial systems, such as in pulp and paper systems, and in heat exchangers. Such methods include paper and wet-lap preservation, mold proofing, and cooling tower fluid preservation. Further, there is a need in systems such as these for biocidal compositions, e.g., antifungal compositions, that do not require use of volatile or flammable organic solvents.
SUMMARY OF THE INVENTION
It has now been surprisingly found that strobilurins, including novel formulations as well as commercially available clay dispersions and microparticulate dispersions, can be used in industrial systems for control of fungal growth.
The present invention provides a method for controlling growth of fungi or mildew comprising combining with an aqueous system a fungicide comprising a strobilurin, wherein the aqueous system comprises at least one of a papermaking machine, wet-lap, and a heat exchange system.
The present invention also provides a method for preserving wet-lap, the method comprising combining wet-lap and a fungicide comprising a strobilurin. The present invention also provides a method for preserving wet-lap comprising combining wet-lap and an effective anti-fungal amount of a strobilurin.
The present invention also provides a method for mold proofing or mildew proofing a cellulosic product, such as a paper product, the method comprising combining with the cellulosic product a composition comprising a strobilurin. The present invention also provides a method for mold proofing or mildew proofing a cellulosic product, such as a paper product, comprising combining with the cellulosic product an effective anti-fungal amount of a strobilurin.
The present invention also provides a paper product including an antifungal amount of a strobilurin.
Strobilurin according to the present invention can be any strobilurin or oudemansin having antifungal properties. The strobilurin preferably includes at least one of kresoxim methyl, azoxystrobin, Compound 5 (described below), strobilurin A, and strobilurin B.
Aqueous systems for methods and compositions of the present invention preferably include at least one of a papermaking machine and a heat exchange system. Included in the present invention are methods wherein the aqueous system comprises a papermaking machine comprising a stock tank, and the strobilurin is combined with fiber furnish in the stock tank. Also included are methods wherein the aqueous system comprises a papermaking machine comprising a pulp refiner, and the strobilurin is combined with fiber furnish in the pulp refiner. Also included are methods wherein the aqueous system comprises a papermaking machine comprising a stock chest, and the strobilurin is combined with fiber furnish in the stock chest. Also included are methods wherein the aqueous system comprises a papermaking machine comprising a flow box, and the strobilurin is combined with fiber furnish in the flow box. Also included are methods wherein the aqueous system comprises papermaking furnish, and the strobilurin is combined with the papermaking furnish. Also included are methods wherein the aqueous system comprises wet-lap, and the strobilurin is combined with the wet-lap.
Also included are methods w
Cash Howard A.
Cronan, Jr. John M.
Chin Peter
Hercules Incorporated
Hug Eric
Rossi Joanne
LandOfFree
Fungicidal method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fungicidal method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fungicidal method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2945713