FOAM DESTABILIZERS

Abstract

The present invention relates to the use of specific alcohols as antifoam and/or defoamer. It also concerns compositions comprising it, and methods for destabilizing a foam.

Claims

1. A method for destabilizing a foam, reducing foam formation of a composition, or breaking a foam in a composition comprising contacting the foam with, or adding into the composition, at least a branched primary alcohol of Formula (I), ##STR00002## wherein: n=0 or 1; and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are linear or branched alkyl groups, identical or different, comprising from 1 to 6 carbon atoms.

2. The method according to claim 1, wherein when n=0, the branched primary alcohol is a primary alcohol trimer, and when n=1, the branched primary alcohol is a primary alcohol tetramer, both being obtainable by the condensation of respectively three and four primary alcohol monomers according to a Guerbet reaction.

3. The method according to claim 1, wherein branched primary alcohols of Formula (I) with n=0 and with n=1, are used.

4. The method according to claim 1, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical.

5. The method according to claim 1, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently chosen among two alkyl groups.

6. The method according to claim 1, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4, individually, comprise between 2 and 4 carbon atoms.

7. The method according to claim 1, wherein the method is for destabilizing a foam of a composition and comprises contacting the foam with at least a branched primary alcohol of Formula (I).

8. The method according to claim 1, wherein the method is for reducing foam formation of a composition, and comprises adding into the composition at least a branched primary alcohol of Formula (I).

9. The method according to claim 1, wherein the method is for breaking a foam of a composition, and comprises contacting the foam with at least a branched primary alcohol of Formula (I).

10. The method according to claim 7, wherein the total quantity of branched primary alcohol(s) of Formula (I) is of at least 0.01% by weight based on the weight of the composition.

11. The method according to claim 8, wherein the total quantity of branched primary alcohol(s) of Formula (I) is of at least 0.01% by weight based on the weight of the composition.

12. The method according to claim 9, wherein the total quantity of branched primary alcohol(s) of Formula (I) is of at least 0.01% by weight based on the weight of the composition.

13. The method according to claim 2, wherein branched primary alcohols of Formula (I) with n=0 and with n=1, are used.

Description

[0090] The invention is further described in the following examples. It will be appreciated that the invention as claimed is not intended to be limited in any way by these examples.

Example 1: Preparation of Branched Primary Alcohol of Formula (I) and Mixture According to the Invention

[0091] 1.1 Preparation of primary alcohol oligomers via a Guerbet reaction

[0092] A Guerbet reaction was conducted as described in patent U.S. Pat. No. 4,518,810 from 3-methylbutanol as starting primary alcohol monomer, and using KOH as a base and palladium as catalyst. The reaction medium was heated up its boiling point.

[0093] The crude reaction mixture was washed several times with demineralized water to remove all of the soaps. The washed product was subsequently filtered and dried under vacuum. The remaining starting primary alcohol monomer was separated by distillation.

[0094] The primary alcohol dimer comprising 10 carbon atoms (2-isopropyl-5-methylhexanol) was then separated by distillation.

[0095] The distillate obtained comprised 99.7 wt % of primary alcohol dimer C10 and 0.3 wt % primary alcohol trimer comprising 15 carbon atoms, and corresponds to comparative mixture 1.

[0096] The residue (“first residue”) was composed of 28.1 wt % of primary alcohol trimer C15, 11.5 wt % of primary alcohol tetramer C20, and 60.4 wt % of remaining primary alcohol dimer C10.

[0097] The remaining primary alcohol dimer was further distilled from this first residue.

[0098] The second residue obtained was then composed of 68.2 wt % of primary alcohol trimer C15, 31.2 wt % of primary alcohol tetramer C20, and 0.6 wt % of primary alcohol dimer C10.

[0099] 1.2 Preparation of mixtures 1-5 according to the invention

[0100] The second residue obtained in Example 1.1 corresponds to mixture 1 according to the invention.

[0101] Mixture 2 according to the invention was obtained by diluting 75 wt % of mixture 1 with 25 wt % of comparative mixture 1.

[0102] The first residue obtained in Example 1.1 corresponds to mixture 3.

[0103] Mixtures 4-5 were obtained by diluting mixture 3 with respectively 25 wt % and 50 wt % of comparative mixture 1.

[0104] Contents of each mixture 1-5 according to the invention and of comparative mixture 1 are described in Table 1 below.

TABLE-US-00001 TABLE 1 Contents of mixtures 1-5 according to the invention and of comparative mixture 1 Primary Primary Primary Total quantity alcohol alcohol alcohol of alcohols of dimer C10 trimer C15 tetramer Formula (I) (wt %*) (wt %*) C20 (wt %*) (wt %) Mixture 1 0.6 68.2 31.2 99.4 Mixture 2 25.4 51.2 23.4 74.6 Mixture 3 60.4 28.1 11.5 39.6 Mixture 4 70.3 21.1 8.6 29.7 Mixture 5 80.0 14.2 5.8 20.0 Comparative mixture 1 99.7 0.3 0 0.3 *based on the weight of the mixture

Example 2: Foaming Characteristics of Compositions According to the Invention

[0105] 2.1 Preparation of compositions 1-5 according to the invention

[0106] Compositions 1-5 according to the invention were prepared by adding 0.5 wt % of a foaming agent (sodium dodecylbenzene sulfonate) and respectively 0.1 wt % of mixture 1-5 according to the invention, into tap water; weight percentages being based on the weight of each composition.

[0107] 2.2 Preparation of comparative composition 1

[0108] Comparative composition 1 was prepared as compositions of the invention, by adding 0.5 wt % of a foaming agent (sodium dodecylbenzene sulfonate), and 0.1 wt % of comparative mixture 1 into tap water.

[0109] 2.3 Foam stability

[0110] The method used to determine the efficiency of the specific alcohols to destabilize foam is based on ASTM D892.

[0111] A blank sample was prepared by adding 0.5 wt % of a foaming agent (sodium dodecylbenzene sulfonate), into tap water, weight percentage being based on the weight of the blank sample.

[0112] 200 mL of each sample (compositions of the invention, comparative composition and blank), were respectively introduced in a 1000 mL graduated cylinder. Each cylinder was then placed in a bath at 24° C. Air was injected in each sample at a flow rate of 94 mL/min for 5 minutes and then the samples were allowed to settle for 10 minutes.

[0113] The volumes of foam were measured just after the air flow stopped (t=0), and monitored for the 10 minutes period.

[0114] Results are summarized in Table 2 below:

TABLE-US-00002 TABLE 2 Evolution of volumes of foam of compositions of the invention and of comparative composition Volumes of foam (mL) Antifoam 0 min 2 min 4 min 5 min 10 min Blank — 580 550 535 530 480 Composition 1 0.1% of mixture 1 115 0 0 0 0 Composition 2 0.1% of mixture 2 115 0 0 0 0 Composition 3 0.1% of mixture 3 240 50 0 0 0 Composition 4 0.1% of mixture 4 265 70 0 0 0 Composition 5 0.1% of mixture 5 285 165 10 0 0 Comparative 0.1% of 350 215 60 35 20 composition 1 comparative mixture 1

[0115] It can be observed with the blank sample, that without any antifoam, a lot of foam is produced: 580 mL of foam at t=0 and still 480 mL after 10 min of rest.

[0116] When a mixture of the invention is added to the aqueous composition comprising a foaming agent, then foam formation is reduced by at least 50% (volume of foam at t=0 of composition 5 is of 285 mL) to up to 80% (volume of foam at t=0 of composition 2 is of 115 mL).

[0117] It can also be observed that globally the more the total quantity of alcohols of Formula (I), the lower the foaming and the faster the foam formed disappears.

[0118] More particularly, the foam formed is not stable and disappears in 4 min by using 0.1% of mixture 4, e.g. 0.03 wt % of alcohols of Formula (I); and faster, in 2 min, by using 0.1% of mixture 2, e.g. 0.07 wt % of alcohols of Formula (I).

[0119] All those results demonstrate that the alcohols of Formula (I) and the mixtures of the invention comprising them, can be used as a good antifoam.

[0120] 2.4 Defoaming property of composition 1 according to the invention

[0121] The method used to determine the efficiency of the mixture of the invention as defoamer is based on ASTM D892.

[0122] Two samples of 200 mL of tap water comprising 0.5 wt % of a foaming agent (sodium dodecylbenzene sulfonate) were each placed into a 1000 mL graduated cylinder which were then placed in a bath at 24° C.

[0123] Air was injected into each sample at a flow rate of 94 mL/min for 5 minutes. Once the injection of air stopped, 0.1 wt % of mixture 1 according to the invention was added on the foam formed of one sample, to form composition 1 of the invention.

[0124] All weight percentage are based on the weight of the corresponding composition.

[0125] The sample which do not received mixture of the invention corresponds to the blank.

[0126] The volume of foam of blank sample was measured just after the air flow stopped (t=0) and for 10 minutes.

[0127] The volume of foam of composition 1 was measured just after addition of mixture 1 (t=0), and monitored for 10 minutes.

[0128] Data are gathered in Table 3 below.

TABLE-US-00003 TABLE 3 Defoaming properties of composition 1 of the invention Volumes of foam (mL) Defoamer 0 min 3 min 5 min 6 min Blank — 600 550 540 530 Composition 1 0.1% of mixture 1 600 120 0 0

[0129] It can be seen that composition 1 of the invention comprising 0.1 wt % of mixture 1 of the invention, can break an existing foam within 5 minutes.

[0130] Branched primary alcohols of Formula (I), in particular a mixture of a branched primary alcohol comprising 15 carbon atoms and of a branched primary alcohol comprising 20 carbon atoms, both obtained from condensation of 3-methylbutanol, may be used as a defoamer.

Example 3: Foaming Characteristics of Comparative Alcohols

[0131] 3.1 Alcohols wich are not of Formula (I)  2-ethylhexanol from Perstorp;  Hexyldecanol, Isofol 16 from Sasol;  2-isopropyl-5-methylhexanol prepared in Example 1.1.

[0132] 3.2 Preparation of comparative compositions 2-4

[0133] Comparative compositions 2-4 were prepared by adding 0.5 wt % of a foaming agent (sodium dodecylbenzene sulfonate) and respectively 0.1 wt % of 2-ethylhexanol, hexyldecanol, a mixture of 60% of 2-isopropyl-5-methylhexanol and 40% of hexyldecanol, into tap water; weight percentages being based on the weight of each composition.

[0134] 3.3 Foaming characteristics of comparative compositions 2-4

[0135] The method used to measure volumes of foam of different comparative compositions 2-4 is the same as method described in Example 2.3.

[0136] Results are given in Table 4 below.

TABLE-US-00004 TABLE 4 Volumes of foam of comparative compositions 2-4 Volume of foam (mL) Antifoam 0 min 10 min Blank — 580 490 Comparative composition 2 0.1 % of 2-ethylhexanol 470 43 Comparative composition 3 0.1% of hexyldecanol 570 430 Comparative composition 4 0.1 % of a mixture of 60% 490 180 of 2-isopropyl-5- methylhexanol and 40% of hexyldecanol

[0137] At t=0, the foam formation is only reduced by at most 19% (comparative composition 2). After 10 minutes, foam remains in each comparative compositions 2-4.

[0138] By comparing comparative composition 3 with compositions according to the invention, we can conclude that using a branched alcohol comprising 16 carbon atoms but which is not of Formula (I), doesn't reduce foaming as much as the alcohols of Formula (I).

[0139] 2-ethylhexanol that is specifically cited and exemplified in patent US 2014/0251605 A1, reduces foaming by only 19% at t=0 and after 10 minutes, foam is still present above the composition, when used at 0.1wt %.