Biodegradable super-spreading, organomodified trisiloxane

Abstract

The invention relates to polyether-modified siloxanes which are both superspreading and readily biodegradable. In particular, the invention is directed to a composition including polyether-modified siloxanes of formula (I)
M.sub.aD.sub.bD.sub.cFormula (I) with M=R.sup.1.sub.3SiO.sub.1/2, D=R.sup.1.sub.2SiO.sub.2/2, D=R.sup.1R.sup.2SiO.sub.2/2, where a is 2, b is between 0 and 0.1, c is between 1.0 and 1.15, 0 and 1.05, R.sup.1 are independently hydrocarbyl having 1 to 8 carbon atoms, preferably methyl, ethyl, propyl or phenyl radicals, especially preferably methyl radicals, R.sup.2 are independently a polyether radical of the formula (II)
R.sup.3O[CH.sub.2CH.sub.2O].sub.m[CH.sub.2CH(CH.sub.3)O].sub.nR.sup.5Formula (II) where m=3.4 to 11.0, n=2.5 to 8.0, wherein m/n=1.9 to 2.8, and R.sup.3 are independently divalent hydrocarbyl radicals having 2 to 8 carbon atoms, and R.sup.5 is hydrogen, wherein the polyether-modified siloxanes of formula (I) having a biodegradability of greater than 60%.

Claims

1. A composition comprising polyether-modified siloxanes of formula (I)
M.sub.aD.sub.bD.sub.cFormula (I) with M is R.sup.1.sub.3SiO.sub.1/2, D is R.sup.1.sub.2SiO.sub.2/2, D is R.sup.1R.sup.2SiO.sub.2/2, where a is 2 b is between 0 and 0.1, c is between 1.0 and 1.15, R.sup.1 are independently hydrocarbyl having 1 to 8 carbon atoms, R.sup.2 are independently a polyether radical of the formula (II)
R.sup.3O[CH.sub.2CH.sub.2O].sub.m[CH.sub.2CH(CH.sub.3)O].sub.nR.sup.5Formula (II) where m is from 3.4 to 11.0, n is from 2.5 to 8.0, and wherein m/n is from 1.9 to 2.8, R.sup.3 are independently divalent hydrocarbyl radicals having 2 to 8 carbon atoms, R.sup.5 is hydrogen the polyether-modified siloxanes of formula (I) having a biodegradability of from 60% to 100% and wherein the molar mass of the polyether radical M(PE) is between 520 g/mol and 660 g/mol.

2. The composition according to claim 1, wherein the sum total of m+n is from 9 up to 19.

3. The composition according to claim 2, wherein a 0.1 percent by weight solution of the polyether-modified siloxanes of formula (I) in water has a spreading area of from 10 to 60 cm.sup.2.

4. The composition according to claim 2, wherein the polyether-modified siloxanes of the formula (I) have an index c between 1 and 1.05, where the m/n ratio is 0.8 to 2.8 and a 0.1% by weight solution of these siloxanes in water has a spreading area of 15 to 60 cm.sup.2.

5. The composition according to claim 1, wherein a 0.1 percent by weight solution of the polyether-modified siloxanes of formula (I) in water has a spreading area of from 10 to 60 cm.sup.2.

6. The composition according to claim 1, wherein the polyether-modified siloxanes of the formula (I) have an index c between 1 and 1.05, where the m/n ratio is 0.8 to 2.8 and a 0.1% by weight solution of these siloxanes in water has a spreading area of 15 to 60 cm.sup.2.

7. The composition according to claim 1, wherein the polyether-modified siloxanes of the formula (I) have a biodegradability of greater than 60%, and the index c is additionally between 1 and 1.05, where the R.sup.5 radical is hydrogen and a 0.1% by weight solution in water has a spreading area of 15 to 60 cm.sup.2.

8. An adjuvant in crop protection wherein the adjuvant comprises the composition according to claim 1.

9. A tank mix additive for spray liquors wherein the tank mix additive comprises the composition according to claim 1.

10. The composition according to claim 1, wherein the sum total of m+n is from 9.5 to 15.

11. The composition according to claim 1, wherein the sum total of m+n is from 10 to 12.

12. The composition according to claim 1, wherein b is 0, c is between 1.00 and 1.10, m is from 3.6 to 9.9, n is from 2.7 to 7.5, R.sup.3 is selected from the group consisting of ethylene, propylene, 1-methylpropylene, 1,1-dimethylpropylene radical, and the polyether-modified siloxanes of formula (I) has a biodegradability of from 63% to 100%.

13. The composition according to claim 1, wherein b is 0, c is between 1.00 and 1.05, m is from 4.5 to 8.5, n is from 3.0 to 6.0, R.sup.3 is CH.sub.2CH.sub.2CH.sub.2, and the polyether-modified siloxanes of formula (I) having a biodegradability of from 65% to 100%.

14. The composition according to claim 1, wherein a 0.1 percent by weight solution of the polyether-modified siloxanes of formula (I) in water has a spreading area of from 15 to 50 cm.sup.2.

15. The composition according to claim 1, wherein a 0.1 percent by weight solution of the polyether-modified siloxanes of formula (I) in water has a spreading area of from 20 to 40 cm.sup.2.

16. A process for preparing polyether-modified siloxanes, comprising the steps of a) purifying an H-siloxane of the formula (V)
M.sub.aD.sub.bD.sub.d(V) with M=R.sup.1.sub.3SiO.sub.1/2, D=R.sup.1.sub.2SiO.sub.2/2, D=R.sup.1R.sup.2SiO.sub.2/2, where a is 2, b is between 0 and 0.1, d is between 1.16 and 3, R.sup.1 are independently hydrocarbyl having 1 to 8 carbon atoms, R.sup.2 is hydrogen b) reacting the purified product of step a) in the manner of a hydrosilylation with a terminally unsaturated polyether of the formula (VI)
R.sup.4O[CH.sub.2CH.sub.2O].sub.m[CH.sub.2CH(CH.sub.3)O].sub.nR.sup.5(VI) where m is from 3.4 to 11.0, n is from 2.5 to 8.0, wherein m/n is from 1.9 to 2.8, R.sup.5 are each independently hydrocarbyl radicals having 1 to 16 carbon atoms or hydrogen, preferably hydrogen or methyl, especially hydrogen, R.sup.4 are independently monovalent terminally unsaturated hydrocarbyl having 2 to 8 carbon atoms and wherein the molar mass of the polyether radical M(PE) is between 520 g/mol and 660 g/mol.

17. The process according to claim 16, wherein the H-siloxane of the formula (V) is purified by employing a thermal separation process.

18. The process according to claim 16, wherein R.sup.1 is selected from the group consisting of methyl, ethyl, propyl or phenyl radicals, m is from 4.5 to 8.5, n is from 2.7 to 7.5, wherein m/n is from 0.55 to 3.00, R.sup.5 is selected from the group consisting of hydrogen or methyl, and R.sup.4 is selected from the group consisting of CH.sub.2CH.sub.2, CH.sub.2CHCH.sub.2, CH.sub.2CHCH(CH.sub.3), CH.sub.2CHC(CH.sub.3).sub.2, especially preferably CH.sub.2CHCH.sub.2.

19. The process according to claim 16, wherein R.sup.1 is a methyl radical, n is from 3.0 to 6.0, wherein m/n is from 0.8 to 2.8, R.sup.5 is hydrogen, and R.sup.4 is CH.sub.2CHCH.sub.2.

20. The process according to claim 16, wherein in m/n is from 1.9 to 2.8.

Description

EXAMPLES

(1) General Methods and Materials:

(2) TABLE-US-00001 Trade name Silwet L-77 Product and trademark of Momentive Silwet 806 Product and trademark of Momentive BREAK-THRU S 240 Product and trademark of Evonik Degussa GmbH, Germany BREAK-THRU S 278 Product and trademark of Evonik Degussa GmbH, Germany BREAK-THRU S 233 Product and trademark of Evonik Degussa GmbH, Germany Sylgard 309 Product and trademark of Dow Corning, USA
Synthesis
Preparation of Me.sub.3SiO[SiMeHO].sub.cSiMe.sub.3

(3) An SiH-functional siloxane of the general formula Me.sub.3SiO[SiMeHO].sub.1.2SiMe.sub.3 was subjected to a fractional distillation under standard pressure. The fraction at a top temperature of 142 C. was determined with the aid of a gas chromatograph to be the product having a purity of 99% by weight of 1,1,1,3,5,5,5-heptamethyltrisiloxane. Thus, the product of the formula (V) has an index d of 1.01.

(4) Subsequently, the distillate and the starting siloxane were mixed in such a way as to obtain the following siloxanes: Me.sub.3SiO[ SiMeHO].sub.1.2SiMe.sub.3, Me.sub.3SiO[ SiMeHO].sub.1.15SiMe.sub.3, Me.sub.3SiO[ SiMeHO].sub.1.10SiMe.sub.3, Me.sub.3SiO[SiMeHO].sub.1.05SiMe.sub.3 and Me.sub.3SiO[ SiMeHO].sub.1.01SiMe.sub.3.

(5) The determination of purity was conducted with the aid of .sup.1H NMR and .sup.29Si spectroscopy. These methods, especially taking account of the multiplicity of the couplings, are familiar to those skilled in the art.

(6) With the aid of these siloxanes, 21 samples were produced analogously to the general preparation method which follows.

(7) General Synthesis Method for Hydrosilylation:

(8) A 1000 ml three-neck flask equipped with stirrer and reflux condenser was initially charged with 0.5 mol of a polyether of the general formula CH.sub.2CHCH.sub.2O[CH.sub.2CH.sub.2O].sub.m[CH.sub.2CH(CH.sub.3)O].sub.nR.sup.5 and heated to 90 C. Subsequently, 10 ppm of Pt were added in the form of a toluenic solution of the Karstedt catalyst (Pt content 2 mol %). The mixture was stirred for 10 min and then 0.38 mol of SiH groups in the form of the SiH-functional siloxane Me.sub.3SiO[SiMeHO].sub.cSiMe.sub.3 was added dropwise within 15 min. An exothermic reaction was observed; the reaction mixture was stirred at 90 C. for a further 4 h. In all cases, it was no longer possible to detect any SiH functions by gas-volumetric means.

(9) TABLE-US-00002 TABLE 1 Samples prepared; the R.sup.5, c, m, n, M (PE) and m/n data relate to formula (I) and, respectively, to formula (II); in the cases when n = 0, m/n is undefined and consequently not stated: Sample R.sup.5 c m n M (PE) m/n Tego XP H 1.00 8.0 3.3 543 2.45 11022 Sample 1 H 1.01 7.8 0.0 343 Sample 2 H 1.20 6.0 3.0 438 1.98 Sample 3 H 1.01 10.0 0.0 440 Sample 4 Me 1.01 7.8 0.0 343 Sample 5 H 1.20 9.9 1.9 545 5.27 Sample 6 H 1.01 14.6 0.0 642 Sample 7 Me 1.01 12.3 0.0 541 Sample 8 H 1.01 12.3 0.0 541 Sample 9 H 1.01 9.9 1.9 546 5.27 Sample 10 H 1.01 8.0 3.3 543 2.45 Sample 11 H 1.01 6.2 4.7 545 1.32 Sample 12 H 1.01 4.9 5.6 540 0.88 Sample 13 H 1.01 3.4 10.2 741 0.33 Sample 14 H 1.01 10.7 8.1 941 1.32 Sample 15 H 1.01 14.4 7.0 1040 2.06 Sample 16 H 1.05 8.0 3.3 543 2.45 Sample 17 H 1.10 8.0 3.3 543 2.45 Sample 18 H 1.15 8.0 3.3 543 2.45 Sample 19 H 1.20 9.2 4.1 643 2.24 Sample 20 H 1.20 3.4 10.2 741 0.33 Sample 21 H 1.20 10.7 8.1 941 1.32

(10) Samples 2, 5, 19, 20 and 21 are noninventive polyether siloxanes since the index c is too high. Samples 1, 3, 4, 6, 7 and 8 are noninventive since the index n is zero. Samples 5 and 9 are noninventive because the content of oxyethylene groups is too low.

(11) Test Solutions:

(12) 0.1% by weight solutions of the test substances in distilled water were made up.

(13) Spreading Test

(14) Spreading was examined by applying a 50 l droplet of the test solutions to a standard polypropylene film (of the Forco-OPPB type, from Van Leer). The droplet was applied with a micropipette. The area of spread was measured 90 seconds after the application. The experiments were conducted at 23 C. and a relative air humidity of 60%.

(15) Surface Tensions

(16) Surface tensions were measured by the Wilhelmy plate method with a Kruss K 12 tensiometer at 25 C.

(17) OECD Biodegradability

(18) Biodegradability was determined in accordance with OECD Method 301F by manometric respirometry at a temperature of 22 C.1 C. The degradation rate was determined within 28 days. The samples had been analysed in a concentration of 100 mg/l and 28 mg/l both against a zero sample (mineral medium) and against a sodium benzoate solution of equal concentration. The values were recorded both after 14 days and after 28 days. After 14 days, no plateau phase had been reached yet. The sewage sludge samples used came from the sewage treatment plant belonging to the Ruhrverband water company, Sunthelle 6, 57392 Schmallenberg on 16 Sep. 2014. The concentration used was 29.6 mg of dry matter per litre of mineral medium; the pH was determined before the start of the experiments to be 7.40.2.

(19) Results of the Interfacial Activity Study:

(20) Comparative substances used for some commercial products, and substances according to U.S. Pat. No. 6,734,141.

(21) Surfactant B: Me.sub.3SiO-[MeRSiO].sub.1.20OSiMe.sub.3, with R=(CH.sub.2).sub.3O(CH.sub.2CH.sub.2O).sub.10 (CH.sub.2CH(CH.sub.3)O).sub.2-H

(22) Surfactant C: Me.sub.3SiO-[MeRSiO].sub.1.00OSiMe.sub.3, with R(CH.sub.2).sub.3O(CH.sub.2CH.sub.2O).sub.20 (CH.sub.2CH(CH.sub.3)O).sub.5-H

(23) Surfactant D: Me.sub.3SiO-[MeRSiO].sub.1.00OSiMe.sub.3, with R=(CH.sub.2).sub.3O(CH.sub.2CH.sub.2O).sub.12.5-H

(24) BREAK-THRU S 233: Me.sub.3SiO-[MeRSiO].sub.1.20OSiMe.sub.3, with R=(CH.sub.2).sub.3O(CH.sub.2CH.sub.2O).sub.9.9 (CH.sub.2CH(CH.sub.3)O).sub.1.9-H

(25) BREAK-THRU S 240: Me.sub.3SiO-[MeRSiO].sub.1.20OSiMe.sub.3 with R=(CH.sub.2).sub.3O(CH.sub.2CH.sub.2O).sub.6 (CH.sub.2CH(CH.sub.3)O).sub.3-H

(26) BREAK-THRU S 278: Me.sub.3SiO-[MeRSiO].sub.1.20OSiMe.sub.3 with R=(CH.sub.2).sub.3O(CH.sub.2CH.sub.2O).sub.7.8-Me

(27) SILWET L77: Me.sub.3SiO-[MeRSiO]OSiMe.sub.3 with R=(CH.sub.2).sub.3O(CH.sub.2CH.sub.2O).sub.8-Me

(28) TABLE-US-00003 Static surface Spread Adjuvant tension [mN/m] diameter [mm] Biodegradable Tego XP 11022 22.9 70 yes Sample 1 21.6 no Sample 2 21.7 no Sample 3 21.6 53 no Sample 4 22.0 70 no Sample 5 21.4 15 Sample 6 22.8 15 Sample 7 22.7 15 no Sample 8 22.7 15 yes Sample 9 21.9 30 Sample 10 21.4 70 yes Sample 11 22.3 80 Sample 12 22.2 75 Sample 13 16 Sample 14 15 Sample 15 26.8 11 Sample 16 21.7 60 yes Sample 17 21.7 60 yes Sample 18 22.0 53 yes Sample 19 23.5 16 Sample 20 34.8 12 Sample 21 25.3 12 Surfactant B 24.1 14 Surfactant C 28.2 10 Surfactant D 23.8 13 BREAK-THRU S 22.3 70 240 BREAK-THRU S 22.0 70 278 BREAK-THRU S 21.4 15 233 Silwet 806 23.5 70 Silwet L77 23.8 80 Silguard 309 23.0 80

(29) Typical superspreaders show a spread diameter in this test of 35 mm or more.

(30) It is found that biodegradable superspreaders have a very defined structure.

(31) The polyether has to have a certain molar mass, but must not be too heavy either. In addition, the polyether has to have a certain number of [CH.sub.2CH(CH.sub.3)O] groups, but a certain ratio between [CH.sub.2CH(CH.sub.3)O] and [CH.sub.2CH.sub.3O] groups still has to be maintained. Furthermore, the siloxane must not be too inhomogeneous.

(32) The results show the advantageous use of the inventive substances.

(33) Biodegradability Results:

(34) TABLE-US-00004 Adjuvant Biodegradability [%] Sample 8 60% Sample 10 66% Sample 1 <60% Sample 2 <60% Sample 7 7% Sample 3 <60%

(35) The results show the easy biodegradability of the inventive substances.

(36) Greenhouse Experiments to Determine the Improvement in Biological Efficacy of a Herbicide

(37) In a greenhouse, common meadowgrass (Poa pratense) was grown in pots. As soon as the plants had reached a height of about 5 to 7 cm, they were sprayed with spray liquor that contained the herbicide Cato (DuPont, Germany, active ingredient: rimsulfuron, concentration: 250 g of active ingredient/kg). The amount of spray that contained the active ingredient corresponded to 200 l/ha. Various adjuvants were added to the spray liquor. For each element of the experiment there were 3 pots that were treated in the same way. The pesticide dosage was 10 g/ha. Commercial standard wetting agents added to the tank were Break-Thru S240 and trisiloxane BREAK-THRU S233, each at 50 ml/ha. The dosage of Tego XP 11022 was 100 ml/ha. The damage to the plants by the herbicide treatment is compared here to untreated plants and the efficacy of the sprayed treatment is expressed as a ratio to the untreated plants. The efficacy was scored in each of the 3 pots per element of the experiment by methods known to those skilled in the art 14 and 28 days after the treatment. The average was calculated and reported as results in the table as a percentage compared to the control without herbicide treatment.

(38) TABLE-US-00005 Herbicide Adjuvant 14 d 28 d Cato, 10 ml/ha none 50% 74% Cato, 10 ml/ha Tego XP 11022, 100 ml/ha 70% 94% Cato, 10 ml/ha BREAK-THRU S240, 50 g/ha 60% 84% Cato, 10 ml/ha BREAK-THRU S233, 50 g/ha 50% 83%

(39) The results show that the inventive composition brought a distinct increase in action compared to herbicide treatment without wetting agent. The advantageous use of the inventive compositions compared to the prior art is shown by this experiment.