CA1129878A

CA1129878A - Copper (ii) alkanolamine complexes useful as algacides and herbicides

Info

Publication number: CA1129878A
Application number: CA209,196A
Authority: CA
Inventors: Carol B. Freedenthal; Marion D. Meyers; Graham A. Stoner
Original assignee: Sandoz AG
Current assignee: Sandoz AG
Priority date: 1973-09-13
Filing date: 1974-09-13
Publication date: 1982-08-17
Also published as: ES430034A1; MX3396E; ATA741674A; BE819908A; CH599754A5; DE2443890A1; ZA745835B; AT353050B; GB1479052A; AU7331774A; DD115024A5; DK484174A; IT1053780B; NL7412162A; FR2243643B1; FR2243643A1; BR7407620D0; CH604528A5; IL45656A; JPS5076228A

Abstract

Abstract of the Disclosure Concentrated aqueous solutions of a copper (II) alkanolamine complex are prepared by reacting copper (II) hydroxide or a copper (II) hydroxide-containing compound with an alkanolamine at a pH of at least 8.5. A
dehydrated form of the complex may be prepared by heating the complex above 100°C. Both forms of the complex are effective in the control of algae and aqueous weeds.

Description

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CANADA

COPpER (II) A~KANOLAMINE COMPLEXES USEFUL AS ALGAECIDES
A~ID HERBICIDES
-The present invention relates to copper complexes and more spec~fically to copper complexes having utility as algaecides and aquatic weed herbicides.
In one broad aspect, the present invention resides in a method of combatting undesirable aquatic plant life in a water locus which comprises applying to the water locus a herb-icidally effective amount of a copper (II) complex which is stable under basic conditions, and which is obtainable by com-plexing copper (II) hydroxide or a copper (II) hydroxide con-taining compound with an alkanolamine (C2-C1O).
In another more specific aspectl the present inYention provides a method of combatting algae in a water locus which comprîses applying thereto an algaecidally effec~
tive amount of a copper (II) complex, the complex being stable under basic conditions and being obtainable by complexing copper (II) hydroxide or a copper (II) hydroxide-containing oompound with an alkanolamine (C2~C1O).
Also provided by the present invention is a storage stable concentrated aqueous solution of a copper (II) complex comprising a copper ~II) complex which is stable under basic conditions and which is obtainable by complexing copper (II) hydroxide or a copper (II) hydroxide containing compound with an alkanolamine (C2-C10), said solution con~
taining from 6% to 10%, by weight, of elemental copper.
The present invention, in a further aspect~
resides in a copper (II) complex obtainable by complexing copper (II) hydroxide or a copper (II) hydroxide containing compound with an alkanolamine (C2~C1O) in a crystalline pure form, said complex ~eing stable under basic conditions.
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~30-~663 Thts ~nvention, tn ~ yet ~urther aspect, res1des tn a dehydr~ted forrn of a copper tTI) complex comprising a dehydrated complex obtainable 6y dehydrakion of a copper (II) complex which is st~ble under basic conditions and is ob-tainable by complex;ng copper (II) hydrox;de or a copper (II) hydroxide~containing compound with an alkanolamine (C2~C1O).
The method of the present invention serves also to comb~t aquatic weeds growing in the water locus when the copper (II) complex is applied in the above-mentioned amount.
The copper (II) complexes employed in the method of the invention are characterised by their notable water solubility even under basic conditions. They are be-lie~ed to be in dimeric form, both in the pure c~ystalline `
state and in solution. They are obtained by complexing copper (II) hydroxide (embracing copper (II) oxide hydrate~ or . copper (II) hydroxide~containing compounds, particularly copper (II) hydroxide double salts, commonly referred to as _ _ .. . , , . _ . . _ .. .
basic . _ . . . . . .. . . . . _ .. .

~L12~87 CANADA

. copper (II) salts, for example, basic copper (II) chloride ~also known as copper (II) oxychloride~ corresponding to the formula Cu(OH)2.CuC12, basic copper (II~ sulphate, corres-ponding to the formula Cu(OH)2.CuS04 or basic copper (II~
carbonate, corresponding to the formula Cu(OH)2.CuC03, with an alkanolamine.
Appropriate alkanolamines are of the fol10wing formula:

~Rl wherein Rl is hydroxyalkyl (Cl~ClO) and each of - R2 and R3 are, independently, hydrogen, alkyl (Cl-C8), hydroxyalkyl ~C2-C8) or aminoalkyl (Cl-C8), the aggregate number of carbon atoms in lS Rl, R2 and R3 being 2 to lO.
Examples of suitable mono- di- and trialkanol-amines are monoethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, diethylethanolamine, aminoethylethanol-amine, monoisopropanolamine, diisopropanolamine, triisopro-panolamine and methyldiethanolamine and mixtures thereof.
The preferred alkanolamine is triethanolamine, espe~ially as the major component of a diethanolamine/tri-ethanolamine mixture, e.g. in the weight ratio of 15 : 85 respectively.
Preferably copper (II) hydroxide or a basic copper ~ salt, especially ~he former~ is employed in the complex formation.
The complexing reaction may~ for example, be .~ .

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CANADA

effected by adding the copper (II) compound to an aqueous solution of the alkanolamine, preFerably a concentrate~
aqueous solution thereof. The reaction is effected at a p~l of at least 8~5, preferably in the pH range 8.5 to 13.0, more preferably 9 to 12, especially 9 to 10. IF necessary, the basicity of the solution may be reduced by the addition of an appropriate acid, e.g. an inorganic acid such as sul-phuriç acid, The reaction temperature is preferably in the range 20 to 80C, more preferably 30~ to 60C. As the reac-tion is generally slightly exothermic, account of this should be taken when working in the above temperature ranges. The reaction period is not critical and generally a period in the range from 20 minutes to 6 hours is appropriate. The mole ratio of the alkanolamine: the copper (II) compound will naturally vary. However, in general, it is preferable to work with a molar excess of the alkanolamine.
~orking up of the reaction mixture may be effected in conventional manner, in order to isolate the resu~ting complex. Thus, for example, as the resulting com- -plex is very soluble in water but insoluble in many organic solvents, the complex may be isolated by the addition of an excess, e.g. twice the volume of the reaction mixture, o~
a water miscible appropriate organic solvent such as acetone whereupon the complex precipitates out.
For trade, storage and application purposes, the complexes are preferably employed in the form of con-centrated solutions, e~g. in the form of aqueous or alco-holic (Cl-C6) solutions, preferably the former. In the pro-duction of a preferred form of concentrated solution, the complex is maintained in the reaction mixture medium without isolation of the complex. Any solids present in the reaction - miY~ture are preferably removed, e.g. by filtration or centri-fuging, to yield a clear concentrated solution. In ~he case where the reaction mixture is employed as a concentrated ... . . .. . .. . . . ..

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solution o~ the complex, the reactants are preferably em~
ployed w~thin a narrow molar ratio range to ensure aga;nst unacceptable amounts of either reactant in the concentrated solution. Thus, in this case, the molar ratio of the a1kanol-amine: the copper (II) compound preferably lies in the range 1.75 to 2,2 : l, more preferably l.g to 2.1 : 1, especially

2 : 1, respectively. In addition, it is preferred that the final pH of the reaction mixture l;es in the range 8.5 to ll, more preferably ~.2 to 9.6.
It has been found that the above-mentioned copper (II) complexes are notably soluble and stable in ~ate), particularly in water having a basic pH. Accorclingly, con-centrated solutions contain~ng from l to 11%~ preferably 6 to 10~, especially 7 to ~,5%, e,g, 7,~ to 8,2~, by welght of elemental copper per unit weight of solution may be produced which are notably stable on standing~ As will be appreciated, as the complexes of the invention are diluted in their algae-cidal or herbicidal use by the water locus to which they are applied, a concentrated application form of the complex is of considerable advantage Such concentrated solutions accor-dingly, also form part of the present invention.
If the copper (II) complex is heated to a tem-perature of above 1~0C, e.g~ from 100 to 130C, preferably from 105 to 115C, and for a period of lO minutes to 5 hours, it is found that 2 mols of water may be driven off to yield a dehydrated form of the complex. The dehydrated complex is a green hygroscopic solid, which is soluble in water and which is slowly hydrolysed in aqueous solution to a solution similar in properties to the original complex. Such dehydrated forms of the complex may accordingly also and advantageously be em-ployed in the method of the invention. Accordingly, such de-hydrated forms of the complex also ~orm part of the present invention.
The structure of the complexes is belieYed to - S ~ 7~

CANADA

vary depending on whether the complex is in pure crystalline form or in solution. Thus, in crystalline form, it is belieYed that only one mol of alkanolamine is coordinated to the Cu2 +
ion. In the form of the solution in which it is formed in accor-dance with the preparative procedures described above, i e. the complex disso1ved in the reaction mixture, it is believed tha~
two mols of alkanolamine are coordinated to the c~2 *ion. For example, when the alkanolamine is triethanolamine, the empi -rical formula excluding water, of the crystalline form is be-lieved to be Cu(OH)2N-(CH2CH20H)3 where as the empirical For-mula, excluding water, of the reaction mixture solution is be-lieved to be Cu(OH)2tN-(CH2CH20H)3~2. In both cases, the com-plex is in dimeric form. In the case of the dehydrated product, 2 mols of water are lost and the empirical formula of the pro-duct, excluding water, is believed to ~e, e.g. in the case of triethanolamine, Cu[OCH2CH2)2NCH2CH20H)]. In each case the coordination num6er of the complexed copper is believed to be six.
The above complexes may be employed in the me-thods of the invention by app1ying the complex, as such, in concentrated solutîon form, or in dehydrated form, to the water locus, pre~erably to obtain a concentration in terms of elemental copper of 6etween 0.1 to 10 ppm9 more preferably 0.1 to 6 ppm, especially 0.2 to 1.0 ppm in the water locus.
The concentration of the complex equivalent to the above-mentioned elemental copper concentrations wil1 naturally depend on and may be computed direct7y from the percentage of elemental copper there~n.
The methods of the invention are effective in combating many forms of algae, including filamentous algae such as Chadaphora and Spirogyra, Planktonic algae such as Microcystis and Anabaena, branched a1gae such as Chara Vulgaris and Nite11a, swimm;ng pool algae common1y referred to as black, brown and red algae, and pond algae such as Dictyosphae~

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rium, Oedogonium, Chtorococcum, Pithophora, Hydrodictyon and Lyngbya.
Aquatic weeds against which the copper (II) complexes are effective are particu1arly of the type Hydr;lla verticillata, Maiad, Milfoil and the like.
The complexes advantageously possess notably low toxicity towards fish as indicated in toxicity tests involving the blue gill sunfish at weight concentrations of 0.5, 1.5 and 2.0 p.p.m. of elemental copper over periods of 8 to ~6 hours and accordingly the complexes are indicated for use in fjsh infested waters.
The complexes also advantageously possess notably - low corrosiveness and a low tendency to deposit elemental copper as indicated in tests comprising jmmersion of normal stee1, stainless steel, brass, aluminium and polyethylene coupons in an aqueous solution of the complexes containing 7%~ by weight of elemental copper, measuring the weight increase in the coupons and observing the appearance of the coupons after a period of 2q days (17 days for stainless steel~ aluminium also being tested in a 0,8% solution with measurement and observation at 2, 4, 8 and 24 hours. The complexes are accor-dingly also indicated for use in waters where they are likely to come into contact with machinery, e.g. pumps and p1ping.
Moreover, as mentioned above, the complexes are notably stable under basic cond;t;ons and are therefore also indicated for use in basic waters, for example, waters having a pH of between 7 and 12.
The ;nvention ;s illustrated with reference to the follow;ng Examples, wherein parts and percentages unless otherwise ind;cated, are by weight.

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630-~663 EXAMPLE 1:

A copper (II) complex was prepared by admixing triethanolamjne ~lith water at a temperature of about 38C using about 1500 pollnds of triethanolam;ne (85% tr;ethanolam;ne-TEA, 15~ diethanolamine~DEA) and 84 gallons of water and adding thereto 500 pounds of cupric hydroxide of a copper content of 54.5~ copper and reacting the complex for two hours at a maximum temperature of 58C. Thereafter, after about two hours an additional 81 gallons of water were added. The copper con^
tent of the solution was a~out 8.10~ before filtering the solution. After filtering the solution and cooling, the copper content was found to be 7.99~ and the dens;ty of the solution at 25C was 1.202~ In a similar manner, solut;ons were made up wh;ch conta;ned 8.1% of copper before filtering and 8.05X of copper after filtering. Another solution con-taining 8.12% of copper before filtering and having a density of l.204 was o~tained.
If filtration is needed, it can be achieyed by adding a filtering aid of conventional properties such as "High~Flow Super-Cel"*, 2% on basis of solution and filtering - b~ a centrifuge or leaf filter.

* Trademark for diatomaceous earth.

EXAMPLE 2:

Three hundred forty~fiYe gallons of the copper hydroxide triethanolamine complex were prepared in the follo-w~ng manner. To 1520 pounds of stirred commercial grade tri-ethanolamine-85 (defined in Example 1) were added:
1) 84 gallons of wateri 2) 23 pounds of 93% sulfuric acid ~for pH adjust~ent) in five gallons of water, and 3) 44Z pounds of copper hydrate (relatiYely pure copper hydroxide containing -9~715~

CANADA

no phosphate and only trace amounts of sulfate) containing 62.6% copper (mole ratio TEA: Cu = 2:1) Af~er stirring for one hour, the temperature of the solution was 55C and all the copper hydrate had dissolved. Eiyhtysix gallons of water was added to the solution and stirring was continued for 15 minutes.
After cooling to 25C, the dark blue product showed the following properties: 8.06% Cu, 1.195 speclfic gravity, 9.8 pH, and 45 cps viscosity. After a period of 15 weeks at room temperature, there was no v;sible deposit or precipitation in the storage containers and the solution re-mained clear.

EXAMPLE 3:
.
To a solution of 298 9. triethanolamine-99 (9~% TEA, 1% DEA) in 190 ml water was added 117 9. basic copper sulfate (3CutOH)2~Cu804~ 54.3% copper). The mixture was stirred for two and one-half hours at a maximum temperature of 35C.
After this period all the basic copper sulfate had dissolved and an additional 190 ml of water was added; stirring was continued for 15 minutes. At 25C the solution had a copper content of 7.8~, a pH of 8.70 and specific gravity 1.22.

EXAMPLE 4:
;
To a solution made from 301 9. triethanolamine-99 and 190 ml of water was added 110 9. technical grade copper oxychloride, 3Cu(OH)2.CuC12, 58% Cu. The mixture was stirred at 65C for four hours. After this period 190 ml of water were ` added; the mixture was stirred another 15 minutes. The un~
- dissolved solid was removed by filtration. The filtrate was a clear blueish~green solution, 8.01% sopper, pH 8.4, and spe-cific gravity 1.204 at 25C.

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CANADA
630-66~3 EX~MPLE 5;

To a solution made from 301 9. triethanolamine-9q and 186 ml of water was added 120 g, baslc copper carbonate, 53% Cu. The mixture was stirred at 70 for five hours. After this period 180 ml of water were added and stirring was con-tinued 15 mlnutes. The undissolved solid was removed by fil-tration yielding a clear dark blue solution, The solution was 7.08% copper, pH ~.4, and specific gravity 1.17 at 25C.

ExAMpLE 6:

A solution of a copper hydroxide/triethanolamine complex prepared as described in Example 1 and containing 8%
of copper was applied to a pond containing filamentous algae and chara in quantity su~ficient to give a concentration in the pond water of 0.4 ppm copper, A 100% kill of the fila-mentous algae and chara was observed in less than one week, ~EX~MPLE 7:
.

Living hydrilla plants contained in l gallon jars in a controlled laboratory environment were treated with the solution used in Example 6 to give copper concentrations of 0.1, 0.2 and 0.4 ppm. Each treatment was carried out on six different sample jars. After 4 weeks at the highest concen-tration, 40% of the hydrilla plants were dead.

~ kill of hydrilla plants Conc. of Cu (ppm)after 2 weeksafter 4 ~eeks 0,1 0 0 0,2 ~ 15 0.4 17 40 ~ .
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EXAMPLE 8:

A sample of the concentrated solution of the copper (II) complex prepared as described in Example 1 was treated ~th an excess of acetone and the precipitated solid was re-covered by filtration. A portion of the dried solid (lO g) was heated in the absence of a solvent at 110 for 1 hour, to give the dehydrated complex as a green hygroscopic solid.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A storage-stable water soluble aqueous concentrate comprising a water solution of a complex of cupric hydroxide with a trialkanolamine of formula I, wherein R1 is hydroxyalkyl (C2-10) and R2 and R3 are hydroxyalkyl (C2-8), the aggregate number of carbon atoms in R1, R2 and R3 being C6 to C10, or with a mixture of a trialkanolamine of formula I with a dialkanolamine (C4-10), ratio of the trialkanolamine or trialkanolamine/dialkanolamine mixture to cupric hydroxide being in the range of from 1.75 to 2.2:1, said solution containing from 6 to 10 percent by weight of elemental copper.

2. A concentrate according to Claim 1, wherein the tri-alkanolamine is triethanolamine.

3. A concentrate according to Claim 2, wherein the tri-ethanolamine is in admixture with diethanolamine, the weight ratio triethanolamine/diethanolamine being 85:15 respectively.

4. A concentrate according to Claim 2 containing from 7.9 to 8.2% by weight of elemental copper.

5. A method of combatting algae in a water locus which comprises applying to them an algaecidally effective amount of a complex of cupric hydroxide with a trialkanolamine or a trialkanolamine/dialkanolamine mixture as defined by claim 1.

6. A method of combatting algae in a water locus which comprises applying thereto an algaecidally effective amount of a complex of cupric hydroxide with a trialkanolamine or a trialkanolamine/dialkanolamine mixture as defined by claims 2 or 3.

7. A method according to claim 5 in which the complex is applied to the water locus in an amount sufficient to obtain a concentration of elemental copper in the water locus of from 0.1 to 10 ppm.

8. A method according to claim 5 in which the complex is applied to the water locus in an amount sufficient to obtain a concentration of elemental copper in the water locus of from 0.1 to 6 ppm.

9. A method according to claim 5 in which the complex is applied to the water locus in an amount sufficient to obtain a concentration of elemental copper in the water locus of from 0.2 to 1 ppm.

10. A method as in claim 7 in which the trialkanolamine is triethanolamine.

11. A method as in claim 10 wherein the triethanolamine is in admixture with diethanolamine, the weight ratio triethanolamine/
diethanolamine being 85:15 respectively.

12. A method as in claims 5, 7 or 8 wherein the complex of cupric hydroxide and trialkanolamine is in the form of a concentrate prior to application to the water locus, such concentrate containing from 6 to 10 percent by weight of elemental copper.

13. A method as in claims 9, 10 or 11 wherein the complex of cupric hydroxide and trialkanolamine is in the form of a concentrate prior to application to the water locus, such concentrate containing from 6 to 10 percent by weight of elemental copper.

14. A method as in claims 5, 7 or 8 wherein the complex of cupric hydroxide and trialkanolamine is in the form of a concentrate prior to application to the water locus, such concentrate containing from 7.9 to 8.2% by weight of elemental copper.

15. A method as in claims 9, 10 or 11 wherein the complex of cupric hydroxide and trialkanolamine is in the form of a concentrate prior to application to the water locus, such concentrate containing from 7.9 to 8.2% by weight of elemental copper.