Plant protecting and regulating compositions – Plant growth regulating compositions – Organic active compound containing
Reissue Patent
2000-05-12
2002-10-01
Clardy, S. Mark (Department: 1616)
Plant protecting and regulating compositions
Plant growth regulating compositions
Organic active compound containing
Reissue Patent
active
RE037866
ABSTRACT:
FIELD OF THE INVENTION
Novel agriculturally acceptable formulations of the herbicide N-phosphonomethylglycine (glyphosate) comprising tertiary or quaternary etheramine or etheramine oxide surfactants are provided.
BACKGROUND OF THE INVENTION
Glyphosate is well known as a highly effective and commercially important herbicide useful for combating the presence of a wide variety of unwanted vegetation, including a agricultural weeds. Glyphosate is conventionally applied as a formulated product dissolved in water to the foliage of annual and perennial grasses and broad leaf plants and the like, is taken up over a period of time into the leaves, and thereafter translocates throughout the plant.
Usually, glyphosate is formulated in commercial compositions in the form of a water-soluble salt. Salts in commercial use include the ammonium salt, alkylamine salts, such as the isopropylamine salt, alkali metal salts, such as the sodium salt, and the trimethylsulfonium salt. However, formulations of glyphosate in its acid form are also used. Typical glyphosate salt formulations include aqueous concentrates, requiring simple dilution and distributions in water for application by the end-user, and water-soluble or water-dispersible dry formulations, especially granules, requiring dissolution or dispersion in water prior to application.
Under most application conditions, the herbicidal efficacy of glyphosate can be significantly enhanced by including one or more surfactants in the composition to be applied. It is believed that such surfactants act partly by facilitating the penetration of glyphosate, a relatively hydrophilic compound, through the rather hydrophobic cuticle which normally covers the external above-ground surfaces of higher plants.
Wyrill and Burnside, Weed Science, Vol. 25 (1977), pp. 275-287, conducted a wide-ranging study of different classes of surfactants as agents for enhancing the herbicidal activity of glyphosate, applied as the isopropylamine salt. They demonstrated that the choice of surfactant has a pronounced effect on the herbicidal performance of a glyphosate formulation, but beyond showing a general tendency for surfactants having high values of hydrophile-lipophile balance (HLB) to be more efficacious than surfactants of the same class having low HLB values, they did not observe any predictive relationship between efficacy and surfactant chemical class. Some of the most effective surfactants identified in the Wyrill and Burnside study were ethoxylated tertiary and quaternary alkylamines.
Commercial formulations of glyphosate have frequently used ethoxylated tertiary alkylamine surfactants, for example an ethoxylated tallowamine having an average of about 15 moles of ethylene oxide (EO) per mole of tallowamine. Monsanto Company of St. Louis, Mo. has for many years sold, under the trademark Roundup® herbicide, glyphosate formulations containing various concentrations of such an ethoxylated tallowamine surfactant.
European Patent No. 0 290 416 to Forbes et al. discloses compositions of glyphosate salts comprising ethoxylated tertiary alkylamine surfactants having less than 15 moles of EO. For example a composition is disclosed comprising the isopropylamine salt of glyphosate and an ethoxylated cocoamine surfactant having an average of 5 moles of EO. It is taught by Forbes et al. that certain herbicidal efficacy advantages are obtainable with such compositions by comparison with compositions where the EO level in the surfactant is around 15 moles.
European Patent No. 0 274 369 to Sato et al. discloses glyphosate compositions comprising ethoxylated quaternary alkylamine surfactants. Several examples are shown wherein the surfactant is an ethoxylated N-methyl cocoammonium chloride surfactant having 2 moles of EO.
A drawback of ethoxylated tertiary alkylamine surfactants of prior art is that when included in concentrate formulations at levels consistent with good herbicidal performance, they tend to be irritant to eyes. In some, but not all, cases, eye irritancy can be reduced by converting the tertiary alkylamine to the corresponding quaternary (N-methyl) alkylamine. U.S. Pat. No. 5,317,003 to Kassebaum discloses that a glyphosate composition containing as the surfactant an ethoxylated N-methyl cocoammonium chloride surfactant having 15 moles of EO is less irritant to eyes than an otherwise identical composition wherein the surfactant is an ethoxylated tertiary cocoamine surfactant having 15 moles of EO.
An alternative solution to the eye irritancy problem is suggested in U.S. Pat. No. 5,118,444 to Nguyen, wherein ethoxylated tertiary alkylamine surfactants are converted to their N-oxides. Examples are shown of glyphosate compositions wherein the surfactant is an ethoxylated tallowamine oxide surfactant having 10, 15 or 20 moles of EO.
A further drawback of ethoxylated tertiary alkylamine surfactants of the prior art is that when water is added to them, they tend to form a stiff gel which adds to the complexity and expense of manufacturing formulations containing such surfactants, by making it difficult to clean vessels and pipes. In practice, this problem is ameliorated by adding an anti-gelling agent, such as polyethylene glycol, to the surfactant.
Never previously disclosed as components of concentrate glyphosate formulations are alkoxylated tertiary or quaternary etheramine or etheramine oxide surfactants. United Kingdom Patent No. 1,588,079 to Texaco Development Corporation discloses examples of ethoxylated alkyloxyisopropylamine and alkylpoly(isopropyl)amine surfactants and methods of preparing them, and suggests they are useful as detergents, dispersants, wetting agents and emulsifiers. Surfactants disclosed have the representative chemical structure
wherein R
1
is C
8
-C
18
alkyl, m is a number from 1 to 5, and x and y are average numbers such that x+y is in the range from 2 to 20.
Tomah Products, Inc. of Milton, Wis. in a brochure titled “Ethoxylated Amines”, dated Aug. 22, 1994, disclose, together with a series of ethoxylated tertiary alkylamines, a number of ethoxylated tertiary etheramine surfactants having the representative chemical structure
wherein R
1
is C
10
-C
26
alkyl and x and y are average numbers such that x+y is in the range from 2 to 15. Suggested uses of the Tomah ethoxylated amines include “agricultural adjuvants”, a well-known application of the ethoxylated tertiary alkylamines listed. No suggestion is made that the ethoxylated tertiary etheramines included in the list would have advantages over the ethoxylated tertiary alkylamines as agricultural adjuvants, nor is there any teaching relevant to the making of concentrate glyphosate compositions with ethoxylated tertiary etheramines.
Another brochure from Tomah Products titled “Quaternaries”, dated Sep. 1, 1994, includes in a list of quaternary amine surfactants a number of ethoxylated quaternary etheramines having the representative chemical structure
wherein R
1
is an aliphatic group exemplified by isodecyl or isotridecyl and x+y is 2. The list of suggested uses for Tomah's quaternaries does not include agricultural adjuvants.
Another brochure from Tomah Products titled “AO-14-2”, dated Aug. 24, 1994, discloses an ethoxylated etheramine oxide which can be deduced to have the representative chemical structure
wherein R
1
is an aliphatic group exemplified by isodecyl and x+y is 2. The list of suggested uses for AO-14-2 does not include agricultural adjuvants.
It is an object of the present invention to provide novel compositions of glyphosate herbicide containing an etheramine surfactant which imparts good herbicidal efficacy, yet having low irritancy to eyes.
It is a further object of the present invention to provide the commercial formulator of glyphosate with an alternative to ethoxylated alkylamine surfactants that (1) allows elimination or substantial reduction of the need for the use of an anti-gelling agent, (2) is soluble in aqueous formulations having higher glyphosate acid equivalent loadings than prior art formulations having comparable efficacy,
Brinker Ronald J.
Sandbrink Joseph J.
Wideman Al S.
Wright Daniel R.
Clardy S. Mark
Monsanto Technology LLC
Senniger Powers Leavitt & Roedel
LandOfFree
Glyphosate formulations containing etheramine surfactants does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Glyphosate formulations containing etheramine surfactants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Glyphosate formulations containing etheramine surfactants will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2994186