# Patent

## Title
Polymeric defoamer additive

## Abstract

The present invention relates to a cost-effective and environmentally friendly polymeric defoamer formulation for use in various industrial applications that does not contain oil, EBS or free silicone.

## Background
TECHNICAL FIELD OF THE INVENTION
The present invention relates to the use of polymers containing alkyl acrylates, hydroxyalkyl acrylates, and/or acrylic acid for defoaming in pulp and paper mill operations, particularly for use toward pulp mill black liquor as well as in the petroleum industry, water treatment, paints and coatings, food and beverage processing, the mining industry, textiles, agriculture, and the like.
BACKGROUND OF THE INVENTION
Defoamers are compositions used in the pulp and paper mill industry for the control of foam in various processes. In addition to the pulp and paper industry, defoamers are also useful in the petroleum industry, water treatment, paints and coatings, food and beverage processing, the mining industry, textiles, agriculture, and the like.
Foam control is a common industrial problem. As such, defoamers are being developed to alleviate this problem. Common defoamer compositions are generally composed of a carrier fluid, a defoaming agent and miscellaneous additives. Foaming problems often have been effectively dealt with by using various petroleum oil-based compositions containing an alkylene diamide and/or hydrophobic silica (silicone coated silica), as well as silicone emulsions and concentrates. Further, cost effective carrier fluids have often been the petroleum oils (mineral oils). Water is also often part of defoamer formulations. Various defoaming compositions have been documented in product literature and patents. See, e.g., U.S. Pat. Nos. 5,082,590; 5,096,617 and 5,071,591.
Oil-based amide defoamers contain a minimum of two ingredients: a wax with a high melting point and an oil carrier (usually derived from petroleum), in which the wax is dispersed. A commonly used wax class is the diamides. A common diamide is ethylene bis-stearamide (EBS), but other diamides or mixtures of diamides can also be found in defoamer blends. EBS is a very hydrophobic molecule that can have deposition potential if not formulated and used correctly. There have been instances where EBS has been found in unwanted deposits in pulp and paper mills. Deposition can lead to discontinuing introduction of defoaming agents that are believed to contribute to the deposition event.
The typical weight fraction of diamide is between about 2 and 10% of the composition whereas the weight fraction of the petroleum oil is often over 80%. The carrier oil varies in composition from one defoamer to another but generally consists of a low viscosity mineral oil with paraffinic or cycloparaffinic hydrocarbons. In addition to the diamides and petroleum oil, the blends may also contain other agents such as hydrophobic silica and silicone oil, various emulsifiers, and stabilizers, but these constituents generally comprise less than about 10% of the formulation.
While these diamide-based compositions are effective defoamers, they have been suspected of contributing to deposition problems in various locations in the mills. (Dorris et al. “Analysis of Amide Defoamers in Kraft Mill Pitch Deposits,” J. Pulp & Paper Science, 11:5, J149-J154, September 1985) There is some evidence that the petroleum oil in this type of defoamer can lead to undesirable by-products in Kraft bleach plants (Allen. et al. manuscript distributed at the 8th International Symposium on Chlorinated Dioxins and Related Compounds, Urnes, Sweden, Aug. 21-26, 1988) In addition, they can demonstrate limited performance efficiency on paper machines because they are not able to completely disperse in water thus they have potential to form deposits and/or oil spots in the paper produced.
Alternative petroleum oil-based defoamers have been prepared from a wide variety of chemicals. For example, U.S. Pat. Nos. 3,751,373 and 3,935,121 disclose defoamers based upon a combination of a fatty acid or alcohol, a polyethylene glycol mono- or di-ester of a fatty acid, a petroleum sulfonic acid, and an organic liquid.
An example of a commercial aqueous-based defoamer is an aqueous emulsion of fatty alcohols. Although the aqueous defoamer does not contain petroleum oil phase, it does however, contain high melting waxes which have been associated at times with undesired effects in processing. These defoamers are generally not as effective as those containing EBS and their homologues, but also do not cause the spotting problem on paper machines that are associated with formulations containing oil, EBS or silicone.
Silicone has commonly been implicated as a contributor to some deposition issues in various processing steps. If not properly formulated and applied, these materials can cause similar or the same problems as oil-containing defoamers. As a result, many pulp and paper mills avoid using silicone containing products.
Therefore there is a need for a cost effective and environmentally friendly defoamer formulation which does not contain oil, EBS or free silicone and performs as good as, if not better than pre-existing defoamers.
SUMMARY OF THE INVENTION
The present invention relates to a cost-effective and environmentally friendly defoamer formulation which does not contain oil, EBS or free silicone for use in various industrial applications. The defoamer formulation of the present invention comprises a mixture of polymer containing acrylic acid, methacrylic acid, or a combination or either in a suitable diluent, an organic carrier, an additive, and/or a surfactant.


DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed towards a cost-effective and environmentally friendly polymeric defoamer formulation for use in several industrial applications including, but not limited to: i) controlling or destroying foam in various processes associated with pulp and paper processing, such as in the Kraft pulping process, sulfite pulping process, thermomechanical pulping (TMP) process, Chemical TMP (CTMP) process, groundwood pulping process, carbonate pulpingprocess, paper machine processes, screen rooms, bleach plants, and the like; ii) preventing inhomogenuity such as craters and rough appearances from forming due to entrained air during the manufacturing of paints and/or coatings for metal, wood, plastics, concrete, and the like; iii) preventing streaking during ink production caused by air bubbles; iv) efficiently controlling flow properties of cement by minimizing air entrainment in the cement slurry; v) increasing drilling efficiency in oil wells by minimizing the effects of unwanted air; vi) controlling foam production during treatment of municipal and commercial waste water; vii) reducing foam buildup associated with the production and storage of ethanol fuel along with cleaning production vessels; viii) preventing and controlling foam buildup associated with the storage of fertilizer in spray tanks in order to free vessel space; ix) preventing the formation of foam buildup in fluids used during metalworking; x) preventing foam buildup and overflow during syntheses of Active Pharmaceutical Ingredients (API); and xi) controlling foam produced during the washing process prior to plastics recycling.
The new defoamer formulation of the present invention unexpectedly produces increases in performance over traditional defoamer technology. Further, the addition of acrylic acid or methacrylic acid to the monomer premix increased performance over monomer premix that did not have acrylic acid or methacrylic acid. The performance was unexpectedly higher than traditional technology at equal dosages.
The essential constituents of the defoamer formulation comprise an acrylate or methacrylate polymer with or without acrylic acid or methacrylic acid in a suitable diluent, organic carrier(s), an additive, and/or a surfactant.
The combination of different monomers in the polymer composition may also be used. The most robust performance is observed when the polymer contains acrylic acid as well as an alkyl acrylate and a hydroxyalkyl acrylate. The addition of acrylic acid to the polymer chain differentiates the polymeric defoamer formulation of the present invention from other polymers used in the past to enhance defoamer performance. The use of methacrylate derivatives are effective as well against foam. A defoamer containing methacrylate derivatives outperforms formulations consisting of the acrylate analogues.
Monomers:
Examples of general monomers used singly or in combination in the present invention to form polymers which are soluble in organic solvents are acrylates, methacrylates, styrene, acrylonitrile, vinyl alkyl ethers, vinyl alkyl esters, hydroxyl alkyl acrylates and methacrylates, fumaric and maleic acid diesters, vinyl acetate, acrylic acid, methacrylic acid, and the like. The preferred general monomers used in the present invention are acrylates and methacrylates.
The preferred monomers of the present invention are of the general formula:




wherein R is hydrogen or methyl.
R′ is hydrogen or a linear or branched alkyl group containing from about 1 to 18 carbon atoms and/or at least one hydroxy group anywhere on the alkyl chain. Suitable R′ groups are selected from, but not limited to, 2-ethylhexyl, 1-, 2-hydroxyethyl, 1-, 2-, or 3-hydroxypropyl, 1-, 2-, or 3-hydroxyisopropyl, or 1-, 2-, 3-, or 4-hydroxybutyl.
The most preferred acrylate monomers include 2-ethylhexyl acrylate (2EHA), 2-hydroxyethyl acrylate (2HEA), and/or acrylic acid.
The most preferred methacrylate monomers include 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, and/or methacrylic acid.
Polymers:
Acrylate polymers useful in the present invention are those polymers obtained by polymerization of one or any combination of an alkyl acrylate monomer, a hydroxyalkyl acrylate monomer and/or acrylic acid monomer. Methacrylate containing polymers that are also useful in the present invention are those polymers obtained by polymerization of an alkyl methacrylate monomer, a hydroxyalkyl methacrylate monomer, and/or methacrylic acid monomer, or combinations of acrylates and methacrylates.
The polymers of the present invention may be prepared in any suitable manner known by one of ordinary skill in the art Generally, they will be prepared with or without the addition of acrylic acid or methacrylic acid in an organic diluent in the presence of a free radical generating catalyst.
The amount of acrylic acid and/or methacrylic acid that may be used in the monomer premix for the preparation of the polymers is selected from, but not limited to, up to about 25 mol % of the polymer, preferably from about 1 to 20 mol % of the polymer, and most preferably about 8 mol % in the polymer.
Organic Diluents:
Examples of suitable organic diluents for use in the present invention may be selected from, but not limited to, diisodecyl phthalate, diisooctyl adipate, diisooctyl phthalate, bis-2-ethylhexyl adipate, dioctyl adipate, 2-ethyl-1-hexanol, isooctyl alcohol, dihexyl phthalate, and/or mixtures thereof. Preferred diluents are diisodecyl phthalate and diisooctyl adipate, with the most preferred being diisooctyl adipate.
Catalysts:
Examples of free radical generating catalysts for use in the present invention may be selected from, but not limited to, 2,2′-azobis(2-methylpropanenitrile), 2,2′-azobis(2,4-dimethylpentanenitrile), or 2,2′-azobis(2-methylbutanenitrile). The most preferred free radical generating catalyst is 2,2′-azobis(2-methylpropanenitrile). Alternatively, redox catalyst systems such as bromate/sulfide or persulfate/ferrous systems may be used. In addition, peroxides such as benzoyl peroxide may be used to generate the free radicals. Alternative free radical generating catalysts may be used as disclosed in U.S. Pat. No. 5,152,925, which is herein incorporated by reference in its entirety.
Organic Carriers:
Examples of suitable organic carriers for use in the present invention may be selected from, but not limited to, the same organic diluents used to make the polymers, polybutenes having a molecular weight of from about 300-1300 atomic mass units, dialkyl phthalates, fatty acid esters, polyethylene and polypropylene glycol and esters thereof, and the like, or mixtures thereof. The preferred organic carriers are polybutenes having a molecular weight of from about 300-1300 atomic mass units and polypropylene glycol, and most preferably polypropylene glycol.
Surfactants:
Examples of suitable surfactants for use in the present invention may be selected from, but not limited to, polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol,alkoxylated dimethylpolysiloxane, alkyl modified siloxanes, fluorine modified siloxanes, mercapto modified siloxanes, hydroxy modified siloxanes, siloxane wax, ethylene oxide/propylene oxide block copolymer, the esters of polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol, ethylene oxide/propylene oxide block copolymer, alkylpolyoxyethylene ethers, alkylpolyoxyethylenes, polyoxypropylene ethers, fatty acid polyoxyethylene esters, fatty acid polyoxyethylene sorbitan esters, fatty acid polyoxypropylene sorbitol esters, polyoxyethylene castor oils, alkylpolyoxyethylene amines and amides, fatty acid sorbitan esters, fatty acid polyglycerin esters, fatty acid sucrose esters, and the like. The preferred surfactants are siloxane-based and polypropylene-polyethylene glycol, and most preferably polyether-modified polysiloxanes and/or alkyl modified siloxanes.
Additives:
Examples of suitable additives for use in the present invention may be selected from, but not limited to, hydrophobic silica, waxes, fatty alcohols, fatty acid esters, fatty alcohol esters, or fatty acids, with the most preferred being hydrophobic silica.
The introduction of surfactants and additives into the resulting defoamer formulation of this invention improves initial and/or overall performance of the defoamer formulations of the present invention. Moreover, it is understood that routine experimentation by one of ordinary skill in the art will determine which and how much specific surfactants and other materials are to be used for a particular application.
Formulations:
The final defoamer formulation may contain a mixture of up to about 60% acrylate or methacrylate polymer with or without acrylic or methacrylic acid in a suitable diluent, about 20-80% organic carrier, up to about 15% additive, and/or up to about 30% surfactants of varying compositions. If acrylic or methacrylic acid is used, the mole percentage of said acid may be up to about 25 mol %.
A preferred mixture of the final defoamer formulation may contain about 15-35% acrylate or methacrylate polymer with or without acrylic or methacrylic acid in a suitable diluent, about 30-70% organic carrier, up to about 10% additive, and about 5-25% surfactants. If acrylic or methacrylic acid is used, a preferred ratio of said acid is about 5-15 mol %.
Another preferred mixture of the final defoamer formulation may contain about 20-30% acrylate or methacrylate polymer with or without acrylic or methacrylic acid in a suitable diluent, about 40-60% organic carrier, about 3-10% additive, and about 10-15% surfactants. If acrylic or methacrylic acid is used, a preferred ratio of said acid is about 8 mol % of the polymer.
One of ordinary skill in the art will appreciate that the individual components of the present invention may change in the formulations depending on the physical and chemical qualities needed for the defoamer in a given process and/or application to which the defoamer will be applied. For example, the dispersibility of the defoamer in water can be adjusted as necessary to obtain the desired performance. An example would be a brown stock washer, paper machine, effluent, and paint defoamer would all have different water dispersibility properties based on their needs.
Depending on the physical and chemical qualities that are needed for a given application or process, the typical dosage or feed rate of from about 2-50 parts per million (ppm) of defoamer will be suitable
Uses:
The formulation of the present invention will effectively prevent foam formation and/or destroy preexisting foam in a variety of industrial applications. Further more, the defoamer formulation of the present invention may or may not be water dispersible.
The cost-effective and environmentally friendly polymeric defoamer formulation is particularly useful in pulp and paper processing. The defoamer formulation of the present invention can be applied in both alkaline and acidic processes in pulp mills without the use of mineral oil, Ethylene bis-stearamide (EBS), or free silicone fluid. The defoamer efficiently controls or destroys foam in various processes, such as but not limited to the Kraft pulping process, sulfite pulping process, thermomechanical pulping (TMP), chemical TMP (CTMP), groundwood pulping, carbonate pulping, paper machine processes, screen room, and bleach plant.
The formulation of the present invention is efficient as a defoamer in the paint and coating industry. The formulation prevents, among other things, undesirable inhomogeneity such as craters and rough appearances from forming due to entrained air during the manufacturing of paints or coatings for metal, wood, plastics, concrete, and the like. In addition, the defoamer formulation also efficiently controls foam buildup in the polymer emulsion associated with water-based PVC paints.
In the ink industry, the formulation of the present invention, among other things, effectively removes and/or controls air bubbles formed during ink production. This in turn prevents any streaking or cratering in the ink, thereby providing a uniform, high quality ink product.
The defoamer formulation is also useful in the cement industry in order to, among other things, efficiently decrease foam production during preparation of cement slurries. As such, air entrainment in the cement slurry is minimized, thus leading to increased flow properties in the cement. The minimization of air entrainment in the cement slurry also results in a more structurally sound cement lattice.
In the oil industry, the formulation of the present invention is also useful as a defoamer. For instance, when added to an oil well, the defoamer effectively lowers the interfacial tension of the crude oil, thus allowing entrained gas to easily escape. This in turn, leads to an increase in drilling efficiency. In addition, the defoamer also effectively controls air entrainment in crude oil during the heating process in distillation columns.
The foam buildup and air entrainment commonly associated with the treatment of waste water in municipal and commercial settings, such as clarifiers, flumes, outfalls, effluent ponds, and the like, are effectively controlled by the formulation of the present invention. Further, the formulation also effectively controls foam and air entrainment in both cold and hot applications.
In the fuel ethanol processing industry, the formulation of the present invention is effective in reducing foam buildup associated with the production and storage of ethanol fuel along with facilitating effective CIP (Cleaning-In-Place) of, among others, evaporators, bottle-washing applications, or anywhere foam may need to be eliminated.
Additionally, for non-fuel ethanol fermentation processes, the formulation is also effective in controlling foam produced by enzymes without compromising either enzyme performance or ethanol quality.
In the fertilizer industry, the formulation efficiently prevents and/or controls foam build-up in spray tanks as a result of, for example, addition of phosphate rock to nitric acid. Addition of the formulation directly to the spray tanks prevents the formation of foam without affecting the performance of the fertilizer. This in turn, frees reactor capacity, which would otherwise be occupied by foam.
The defoamer formulation of the present invention is also useful in the metalworking industry. The formulation effectively prevents the formation of foam in various metalworking fluids, such as soluble oil, semi-synthetic, synthetic, micro-emulsion fluids, and the like during metal production.
In the food and beverage processing industry, the formulation of the present invention efficiently prevents and/or destroys foam production in vessels used for washing, cutting, heating, and the like. As a result, overflow of foam out of the vessels is prevented and more vessel space is made available.
The formulation of the present invention is also useful as a defoamer in the medical and pharmaceutical industries without compromising the effectiveness of the Active Pharmaceutical Ingredient (API). The formulation effectively prevents and/or destroys foam production in reaction vessels during large-scale syntheses of API's, which also prevents the foam from overflowing out of the reaction vessels.
In the plastics recycling industry, prior to recycling, the plastics must be washed with detergents. The conditions are rather harsh with high temperatures and highly basic pH's. As a result, severe foaming is problematic. The defoamer formulation of the present invention effectively controls the foaming associated with the detergents and harsh conditions associated with plastics recycling.
The defoamer formulation of the present invention is in no way limited only to the uses discussed above. As such, the defoamer formulation of the present invention can also be used in any industry that may require the control or destruction of foam.
ABBREVIATIONS AND DEFINITIONS
“Foam” is defined herein to mean a dispersion of a gas (usually air) in a liquid or solid.
“Defoamer” is defined herein to mean a compound or composition used to inhibit the formation of foam or destroy existing foam.
“Water dispersible” is defined herein to mean a liquid, semi-solid, or solid which is not soluble in aqueous media, but rather can be uniformly distributed in an aqueous media.
“Water insoluble” is defined herein to mean a liquid, semi-solid, or solid which is not capable of being completely dissolved or uniformly distributed in an aqueous media.
“Aqueous media” is defined herein to mean media in which water is the main constituent. Aqueous media may comprise water that is completely clear, a colloidal suspension, pulp slurry, and the like.
“Free silicone” is defined herein to mean silicone that is not bound to another non-silicone constituent.
“Dose” is defined herein to mean the amount of defoamer formulation needed to be added to a particular application or process to achieve a desired positive outcome.
“CIP” as used herein refers to Cleaning-In-Place and is defined herein to mean spray cleaning a vessel with a minimum amount of hand detailing.
“2EHA” as used herein refers to 2-ethylhexyl acrylate.
“2HEA” as used herein refers to 2-hydroxyethyl acrylate.
“DIOA” as used herein refers to diisooctyl adipate.
“DIDP” as used herein refers to diisodecyl phthalate.
“PVC” as used herein refers to polyvinyl chloride.
“Room temperature” as used herein refers generally to temperatures in the range of 20 to 30° C., with an average temperature being 25° C.
EXAMPLES
Evaluation of Samples
The Foam and Entrained Air Tester (FEAT) is a testing apparatus used to determine the efficacy of defoamers in a laboratory setting. The apparatus measures the change in the density of the liquor/filtrate as the defoamer is introduced. Traditional defoamer foam cell tests only measure the effects a defoamer has on the surface foam. The measure of the change in density of a filtrate is a direct measurement of the change in entrained air. In pulp and paper mills, presence of entrained air can impede mat formation and drainage.
Testing of the different samples utilizes a recirculatory foam cell attached to a pump. The hose leading from the pump is connected to a density meter, which is then connected back to the top of the foam cell. Black liquor from the first stage washer from a southeast Georgia Kraft process mill is used in all of the testing. The liquor is heated to 82° C. The heated black liquor is added to the test unit and pumped through the unit to fill the lines. The level of the liquor is then lowered to the 18 cm mark on the tube before the test is started. Once the pump is turned on, the defoamer is added when the density dropped, due to air entrainment, to a specified density measurement, usually between 0.8 and 1.0 g/cc. The tests are run for a total of 180 seconds. A line graph is then generated to show the change in density of the liquor of the time period. The area under the curve for each test is then calculated. There are two different areas calculated: the area under the curve during the first 30 seconds is calculated to provide a measure of the initial deaeration of the sample, and the area under the curve for the total test time is calculated to provide a measure of the overall performance of each sample. Those samples having the highest area under the curve measurements are those samples that performed the best. All tests were run in duplicate and the averages of the two runs are reported. Results are reported both as area under the curve and as a percent difference when compared to the standard. Unless otherwise noted, the standards are the example products from the patent. The range of experimental error for this test method is +/−10%. Testing of other filtrates (effluent, paper machine, starch, etc.) was completed using the above method as well. Table 1 below is merely an illustration of how data is presented in the following examples.







TABLE 1







Example of Results:












Product 1
Product 2
Product 3
Product 4



3000 μL
3000 μL
200 μL
1000 μL















1st 30 Seconds
12.3
12.3
11.0
10.1


Area


Total Runtime
72.3
74.4
85.4
61.9


Area


Percent Difference from

2.9%
18.1%
−14.3%


Standard









Table 1 above shows the product name and the dosage used for that test (Product 1, dosed at 3000 μL). The number below the name and dosage is the area under the curve during the first 30 seconds of the test (12.31930). The second number is the area under the curve for the entire test time (72.28433). The bottom numbers are the % differences in total area between the standard/control's total area under the curve and the experimental samples' total area under the curve. In the case above, Product 3, dosed at 200 μL, yielded an 18.1% increase in performance over Product 1. Product 4, dosed at 1000 μL, yielded a 14.3% decrease in performance when compared to Product 1. In the above example, Product 3 would be the best performing product—not only did the product provide an 18% increase in performance, the product accomplished the increase despite having a dosage that was 1/15th that of the standard, Product 1.
All parts and percents are by weight unless otherwise specified. Additionally, all trademarks are defined throughout the specification.
Example 1
Preparation of Acrylate Polymer in DIOA
A polymer containing 10-30% hydroxyl alkyl acrylate and 70-90% alkyl acrylate by weight percent was prepared as follows: 250 g of diisooctyl adipate (DIOA) was placed into a reaction flask. A vacuum was applied for 20 minutes to remove dissolved air. DIOA was sparged with nitrogen while being heated to 79-82° C. with mixing. Once at temperature and with the nitrogen sparge and constant mixing, a free radical generating compound was added and allowed to dissolve over a 5 minute period. Meanwhile, the acrylate monomers were pre-mixed in a beaker. The monomer mixture was added to the DIOA diluent through an addition funnel at a rate of approximately 1.5 g/minute, making sure to maintain a temperature of approximately 79-82° C. After the monomer blend addition, 48 g of DIOA were used to rinse the monomer blend container and addition funnel, and the DIOA rinse was added to the reaction flask. Another 0.5 g of free radical generating compound was added, and the mixture was held at 79-82° C. with mixing and nitrogen for 2 hours. The mixture was then air cooled to room temperature.
The resulting polymer was clear and colorless, having a viscosity of 1100 cps as measured by a Brookfield viscometer, spindle 3, speed 50 at 25° C.
Example 2
Comparison to Example II of U.S. Pat. No. 5,152,925 ('925)
Experimental products were made following the formulations given in Example II of the '925 patent. Analogs of the examples were also made using the polymer from Example 1 above. Below are the formulations, along with their corresponding numerical designations, i.e., 265-57-1.







TABLE 2







Example Products from the ′925 Patent













265-57-1*






(standard)
265-55-1
265-57-3







Polybutene

70
50



DIDP
70

20



Acrylate Polymer in
30
30
30



DIDP







*Example from the ′925 patent













TABLE 3







Analogs of the ′925 Patent Examples with Acrylate polymer in DIOA











265-57-2
265-55-2
265-57-4
















Polybutene

70
50



DIDP
70

20



Acrylate Polymer in
30
30
30



DIOA

















TABLE 4







Best Previous Performing Defoamer









265-54-2














Polypropylene Glycol
58.5



Hydrophobic Silica
3



Acrylate Polymer in DIOA
23.5



Polyether-Modified
10



Polysiloxane Silicone



Surfactant



Alkyl Modified Siloxane
5



Silicone Wax

















TABLE 5







Polybutene Containing Samples*











265-55-1
265-55-2
265-54-2



3000 μL
3000 μL
200 μL
















1st 30 Seconds
6.5
8.4
11.2



Area



Total Runtime
53.1
73.3
84.7



Area



Percent Difference

38.1%
59.6%



from Standard







*See Tables 2, 3, and 4 above for formulations corresponding to numeric designations













TABLE 6







DIDP Containing Samples*











265-57-1
265-57-2
265-54-2



3000 μL
3000 μL
200 μL
















1st 30 Seconds
7.9
6.5
11.4



Area



Total Runtime Area
59.4
56.4
87.3



Percent Difference

−5.1%
46.9%



from Standard







*See Tables 2, 3, and 4 above for formulations corresponding to numeric designations













TABLE 7







Polybutene and DIDP Containing Samples*











265-57-3
265-57-4
265-54-2



3000 μL
3000 μL
200 μL
















1st 30 Seconds Area
8.0
8.8
11.4



Total Runtime Area
54.6
67.8
87.3



Percent Difference

24.3%
60.0%



from Standard







*See Tables 2, 3, and 4 above for formulations corresponding to numeric designations






Testing Results:
Testing was completed in three different sets: products containing just polybutene, products containing just DIDP, and products containing a combination of polybutene and DIDP. Each set was run twice, and the runs were averaged. There was a large disparity in the dosage of the products. The examples from Example II of the '925 patent, as well as the analogs, needed a dosage of 3000 μL in order to produce an acceptable test, while experimental 265-54-2 needed only 200 μL, while yielding results that ranged from 46.9 to 60.0% better performance.
Example 3
Testing the Effects of Surfactants
The '925 patent states that the addition of a water soluble surfactant having a cloud point of 21-38° C., at levels of 0.25% to 3%, increases the drainage properties of the examples while maintaining excellent defoaming activity. In laboratory testing, the increase in drainage is typically measured as an increase in the performance of the defoamer during the 30 seconds after the defoamer is introduced. In an effort to test the examples, experimental products were made using the formulations from Example II in the '925 patent, and adding 0.25% and 3% of an ethylene oxide/propylene oxide block copolymer surfactant which meets the water solubility and cloud point criteria. These experimental products were tested and compared to the defoaming performance of 265-54-2. As in the case of Example II above, analogs of each of the samples were made using the Acrylate polymer in DIOA. Below are the formulations and test results obtained.







TABLE 8







Formulations Containing Polybutene and Ethylene Oxide/Propylene


Oxide Block Copolymer Surfactant












265-56-1
265-56-2
265-56-3
265-56-4















Polybutene
69.8
69.8
67
67


(MW = 370)


Acrylate
30

30


Polymer in


DIDP


Ethylene
0.3
0.3
3
3


Oxide/Propylene


Oxide Block


Copolymer


Surfactant


2EHA/2HEA

30

30


Polymer in


DIOA
















TABLE 9







Testing Results from Polybutene and Ethylene Oxide/Propylene Oxide


Block Copolymer Surfactant Containing Defoamers*














265-56-1
265-56-2
265-56-3
265-56-4
265-54-2
265-54-2



3000 μL
3000 μL
3000 μL
3000 μL
150 μL
200 μL
















1st 30
7.0
8.4
10.4
11.4
9.0
11.2


Seconds Area








Total
55.3
72.6
69.1
79.3
68.7
84.7


Runtime Area


















Percent Difference
31.4%
25.0%
43.4%
24.3%
53.3%


from Standard





*See Tables 4 and 8 above for formulations corresponding to numeric designations






Testing Results:
From Table 9 above, testing results show 265-56-2, 265-56-4, and 265-54-2 dosed at 200 μL, all of which contain the Acrylate polymer in DIOA outperform 265-56-1 and 256-56-3, both of which contain the Acrylate polymer in DIDP, regardless of the surfactant level. Testing also shows that the 265-54-2 formulation dosed at 200 μL outperforms all of the other examples at 1/15th the dosage, regardless of which polymer is present.







TABLE 10







Formulations Containing DIDP and Polybutene












265-58-1
265-58-2
265-58-3
265-58-4















DIDP
69.8
69.8
67
67


Acrylate
30

30


Polymer in


DIDP


Polybutene
0.3
0.3
3
3


Acrylate

30

30


Polymer in


DIOA
















TABLE 11







Testing Results from DIDP and Polybutene Containing Defoamers*














265-58-1
265-58-2
265-58-3
265-58-4
265-54-2
265-54-2



3000 μL
3000 μL
3000 μL
3000 μL
150 μL
200 μL
















1st 30
7.5
6.3
9.3
7.5
9.8
11.4


Seconds Area








Total
58.3
55.9
65.0
62.8
69.4
87.3


Runtime Area


















Percent Difference
−4.1%
11.5%
7.7%
19.0%
49.7%


from Standard





*See Tables 4 and 10 above for formulations corresponding to numeric designations






Testing Results:
The results in Table 11 above show that 265-58-3, which contains high levels of DIDP diluent in conjunction with the Acrylate polymer in DIDP outperforms 265-58-2 and 265-58-4, which contain the Acrylate polymer in DIOA diluted with DIDP. This difference in performance is within the range of experimental error. Testing also shows that the 265-54-2 formulation outperforms all of the other examples at 1/15th and 1/20th the dosage, regardless of which polymer is present.







TABLE 12







Formulations Containing DIDP, Polybutene and Ethylene


Oxide/Propylene Oxide Block Copolymer Surfactant












265-58-5
265-58-6
265-58-7
265-58-8















Polybutene
50
50
50
50


DIDP
19.8
19.8
17
17


Acrylate
30

30


Polymer in


DIDP


Ethylene
0.3
0.3
3
3


Oxide/Propylene


Oxide Block


Copolymer


Surfactant


Acrylate

30

30


Polymer in


DIOA
















TABLE 13







Testing Results from DIDP, Polybutene and Ethylene Oxide/Propylene


Oxide Block Copolymer Surfactant Containing Defoamers*














265-58-5
265-58-6
265-58-7
265-58-8
265-54-2
265-54-2



3000 μL
3000 μL
3000 μL
3000 μL
150 μL
200 μL
















1st 30
8.0
9.2
10.5
10.4
9.8
11.4


Seconds Area








Total
56.1
68.5
63.4
64.8
69.4
87.3


Runtime Area


















Percent Difference
22.1%
13.1%
15.6%
23.6%
55.6%


from Standard





*See Tables 4 and 12 above for formulations corresponding to numeric designations






Testing Results:
These test results show that 265-58-6 and 265-58-8, which contain the Acrylate polymer in DIOA consistently outperforms 265-58-7, regardless of the surfactant level. Testing also shows that the 265-54-2 formulation outperforms all of the examples at 1/15th and 1/20th the dosage, regardless of which polymer is present.
Example 4
Efficacy of the Defoamer Formulations
To test the efficacy of the defoamer formulations, products were made and tested against 265-54-2. Below are the formulations and test results from this testing.







TABLE 14







Formulations Containing Hydrophobic Silica










265-59-1
265-59-2















Acrylate
30




Polymer in



DIDP



Acrylate

30



Polymer in



DIOA



Hydrophobic
5
5



Silica



DIDP
15
15



Polybutene
50
50

















TABLE 15







Testing Results from Defoamer Formulations Containing


Hydrophobic Silica*











265-59-1
265-59-2
265-54-2



3000 μL
3000 μL
200 μL
















1st 30 Seconds Area
12.3
12.3
11.0



Total Runtime Area
72.3
74.4
85.4



Percent Difference

2.9%
18.1%



from Standard







*See Tables 4 and 14 above for formulations corresponding to numeric designations






Testing Results:
Testing did show an increase in performance of 265-59-2 when 5% hydrophobic silica was incorporated into the products. However, 265-59-2 did not perform as well as 265-54-2, even at 15 times the dosage. Repeated testing of experimental defoamer 265-54-2 shows superior defoaming capabilities. A dosage of 3000 μL, (approximately 60 ppm) is considered excessive in laboratory testing of first stage black liquor filtrate. A typical dosage for an oil based defoamer in 1st stage black liquor is typically 250-500 μL.
It was first assumed the change from DIDP to DIOA was neutral, based on Foam Cell test (measuring foam height vs. time) results, but upon beginning testing and evaluation of developed samples using the FEAT unit to evaluate samples (FEAT measures liquid density over time) it was discovered there was in fact a difference between the two polymer systems; the polymer made in DIOA performed better than the polymer made in DIDP.
Example 5
Direct Comparison of the Polymer in the Different Diluents
Samples were made and tested in an effort to test whether the diluent used affects the performance of the polymer in the FEAT unit. Below are the formulations of the products and the results from the testing.







TABLE 16







Formulations of Polymers made and Diluted


in Different Diluents












265-57-1
265-57-2
265-83-1
265-83-2















Acrylate Polymer
30

30



in DIDP


Acrylate Polymer

30

30


in DIOA


DIDP
70
70


DIOA


70
70
















TABLE 17







Results from Testing Polymers in DIDP










265-57-1
265-57-2



3000 μL
3000 μL















1st 30 Seconds Area
7.9
6.5



Total Runtime Area
59.4
56.4



Percent Difference from

−5.1%



Standard

















TABLE 18







Results from Testing Polymers in DIOA










265-83-1
265-83-2



3000 μL
3000 μL















1st 30 Seconds Area
1.7
1.2



Total Runtime Area
6.8
8.3



Percent Difference from

21.8%



Standard










Testing Results:
Table 17 shows that the Acrylate polymer in DIOA, when diluted in DIDP, has slightly lower performance than the Acrylate polymer in DIDP diluted in DIDP, but within experimental error. Table 18 shows that the Acrylate polymer in DIOA, when diluted in DIOA, improves the performance 22% over 2EHA/2HEA polymer in DIDP diluted with DIOA.
Example 6
Improvement of Acrylate Polymer in DIOA with Acrylic Acid
Experiments were conducted in an effort to determine if the performance of the Acrylate polymer in DIOA could be improved. The procedures of Example 1 above were repeated to prepare and evaluate a series of polymers to determine their defoaming capacity. These products were produced by lowering the amount of hydroxyalkyl acrylate and alkyl acrylate in the DIOA diluted polymer and replacing that amount with glacial acrylic acid, which was added into the premix of the monomers. The resulting polymers where used as a replacement for the polymer component of 265-54-2. Below is the mol % of acrylic acid added to the monomer pre-mix, as well as the formulations and results from the testing.







TABLE 19







Mol % Acrylic Acid in Polymer










Numeric
Mol % Acrylic



Designation
Acid in Polymer







265-64
1%



265-60
4.3%  



265-65
8%



265-67
20% 

















TABLE 20







Formulations with Acrylic Acid Polymers












265-66-1
265-61
265-66-2
265-68















Polypropylene Glycol
31.5
31.5
31.5
31.5


10% Hydrophobic Silica
30
30
30
30


Base in Polypropylene


Glycol


Polyether-Modified
10
10
10
10


Polysiloxane Silicone


Surfactant


Alkyl Modified Siloxane
5
5
5
5


Silicone Wax


265-64
23.5


265-60

23.5


265-65


23.5


265-67



23.5
















TABLE 21







Performance of Formulations Containing Acrylic Acid Polymers*













265-54-2







Acrylate







Polymer
265-66-1
265-61
265-66-2
265-68



in DIOA
1 Mol %
4 Mol %
8 Mol %
20 Mol %















1st 30
9.3
9.6
9.6
10.2
10.7


Seconds







Area







Total
40.1
50.2
52.5
56.6
54.4


Runtime







Area
















Percent Difference
25.4%
31.0%
41.4%
35.9%


from Standard





*See Tables 4 and 20 above for formulations corresponding to numeric designations






Testing Results:
The testing shows that by including acrylic acid in the monomer premix, the resulting polymer provides a significant increase in performance to the final defoamer formulation when compared to 265-54-2, which has no acrylic acid. This improved performance was well beyond the increase that was observed by switching from DIDP to DIOA. Thus, this level of increase was unexpected.
Effect of Different Diluents on Performance:
After showing that the addition of 8 mol % acrylic acid to the Acrylate polymer in DIOA significantly improves performance, samples of the polymer were made in DIDP to examine if the difference in diluent will affect performance. The manufacturing procedure from Example 1 above was used, whereby the DIOA was replaced with DIDP. The resulting polymer, 265-84, was a very viscous liquid (>140,000 cps). The products that were made using 265-84 were tested against the products made from DIOA analog 265-65. Below are the formulations and results from the testing.







TABLE 22







Formulations Containing 8 Mol % Acrylic Acid












265-85-1
265-85-2
265-85-3
265-85-4















DIDP
70

70



DIOA

70

70


265-65


30
30


8 Mol % in


DIOA


265-84
30
30


8 Mol % in


DIDP
















TABLE 23







Results of Testing the 8 Mol % Polymers












265-85-1
265-85-2
265-85-3
265-85-4



Avg
Avg
Avg
Avg



2500 μL
2500 μL
2500 μL
2500 μL

















1st 30
3.1
7.3
5.4
8.0



Seconds



Area



Total
3.2
37.9
34.3
63.7



Runtime



Area












Percent Difference
1093.2%
979.3%
1904.6%



from Standard










Testing Results:
Table 23 shows that 8 mol % polymer, 265-85-4, made in DIOA and diluted with DIOA outperforms polymer, 265-85-3, made in DIOA and diluted with DIDP. Polymer, 265-85-2, made in DIDP and diluted with DIOA even outperforms 265-85-3. Also, an increase in performance of over 1900% was observed over the standard. Although an increase in performance was expected, an increase of over 1900% certainly was not.
Effect of 8 Mol % Acrylic Acid:
The 8 mol % acrylic acid polymer was tested against Acrylate polymer in DIDP and Acrylate polymer in DIOA. Below are the formulations and results from the testing.







TABLE 24







Formulations Containing 8 Mol % Acrylic Acid











Acrylate
Acrylate




Polymer in
Polymer in



DIDP
DIOA
8 Mol %
















2EHA/2HEA
30





Polymer in DIDP



DIDP
70



2EHA/2HEA

30



Polymer in DIOA



DIOA

70
70



265-65 8 Mol %


30



Acrylic Acid

















TABLE 25







Results from 8 Mol % Acrylic Acid Testing in DIOA













8 Mol %



Acrylate
Acrylate
Acrylic



Polymer in
Polymer in
Acid in



DIDP Avg
DIOA Avg
DIOA Avg
















1st 30
4.9
6.6
8.9



Seconds



Area



Total
39.4
47.9
60.8



Runtime



Area












Percent Difference from

21.4%
54.4%



Standard










Testing Results:
Testing shows that the product containing 8 mol % acrylic acid performed 54% better than the product containing Acrylate polymer in DIDP, and 33% better than the product containing Acrylate polymer in DIOA.
Example 7
Comparison to Oil Based Defoamers
One of the criteria that was set for the present invention was that the newly created defoamer formulations must perform as well as traditional oil based defoamers (paraffinic oil, EBS, silicone fluid, hydrophobic silica). The oil based defoamer that was chosen as the standard contained 4.9% EBS, 4.5% hydrophobic silica, 0.5% Polydimethylsiloxane (PDMS) silicone fluid, 0.5% silicone surfactant, and the remainder as paraffinic oil. This defoamer was tested against different experimental defoamers at equal dosages (150 μL) in 82° C. first stage filtrate. Below are the formulations and results from the testing.







TABLE 26







Results for New Formulations Versus Traditional Oil Based


Defoamer*















265-54-2








Acrylate







Oil Base
Polymer
265-66-1
265-61
265-66-2
265-68



Defoamer
in DIOA
1 Mol %
4 Mol %
8 Mol %
20 Mol %
















1st 30
8.7
6.2
6.6
6.5
7.1
7.6


Seconds Area








Total
10.7
23.5
33.7
35.9
40.1
37.9


Runtime Area


















Percent Difference
120.2%
215.4%
236.5%
275.5%
254.9%


from Standard





*See Tables 4 and 20 above for formulations corresponding to numeric designations






Testing Results:
Testing shows that defoamer, 265-54-2, containing the DIOA diluted polymer from Example 1 above provided a 120% increase in performance over the oil base standard. With an 8 mol % addition of acrylic acid to polymer, 265-66-2, there is an unexpected increase of 275.5% in performance over traditional oil based defoamers.
Acrylic Acid Polymer at Different Concentrations:
The 8 mol % acrylic acid polymer was tested against Acrylate polymer in DIDP and Acrylate polymer in DIOA in an oil based defoamer formulation at 3, 6, and 10%. Below are the formulations and results from the testing.







TABLE 27





Oil Based Formulations


















Generic Oil




Base:






EBS
2%



Hydrophobic
2%



Silica




Paraffinic Oil
96%



Products Tested:






















265-
265-
265-
265-
265-
265-
265-




265-94-2
94-3
94-4
94-5
94-6
94-7
94-8
94-9
265-94-10





Generic Oil
97%
97%
97%
94%
94%
94%
90%
90%
90%


Base











Acrylate
3%


6%


10%




Polymer in











DIDP











Acrylate

3%


6%


10%



Polymer in











DIOA











8 Mol %


3%


6%


10%


Acrylic











Acid
















TABLE 28







Results from Oil Based Defoamer Testing with 3% Polymer












3% Polymer
265-94-2
265-94-3
265-94-4
















1st 30 Seconds
12.0
12.1
10.7



Area



Total Runtime
49.5
50.8
44.6



Area












Percent Difference from

2.6%
−10.0%



Standard










Testing Results:
Testing shows that the acrylic acid containing polymer, 265-94-4, does not perform as well as the Acrylate polymer in DIDP or the Acrylate polymer in DIOA at 3% concentration.







TABLE 29







Results from Oil Based Defoamer Testing with 6% Polymer












6% Polymer
265-94-5
265-94-6
265-94-7
















1st 30 Seconds
10.6
11.1
10.5



Area



Total Runtime
43.8
44.1
46.1



Area












Percent Difference from

0.7%
5.2%



Standard










Testing Results:
Testing shows that the use of acrylic acid containing polymer, 265-94-7, increases performance when added at 6%, but the increase is within experimental error.







TABLE 30







Results from Oil Based Defoamer Testing with 10% Polymer












10% Polymer
265-94-8
265-94-9
265-94-10
















1st 30
10.8
10.8
10.4



Seconds



Area



Total
40.9
40.1
53.5



Runtime



Area












Percent Difference

−1.9%
31.0%



from Standard










Testing Results:
Testing shows that a 10% addition of acrylic acid containing polymer, 265-94-10, in an oil based defoamer increases performance 31% over the Acrylate polymer in DIDP, and 29% over the Acrylate polymer in DIOA.
Dosage Needed to Match the Performance of the Defoamers of the Present Invention
Tests were completed to determine the dosage of the oil based defoamer that was needed in order to match the performance of the polymeric containing defoamers of the present invention. Below are the results from that testing.







TABLE 31







Results Showing the Amount of Oil Based Defoamer Needed to Match


Polymeric Performance













265-54-2





Oil Base
Acrylate
265-66-2
Oil Base



Defoamer
Polymer in
8 Mol %
Defoamer



200 μL
DIOA 200 μL
200 μL
1000 μL














1st 30 Seconds Area
12.1
10.5
10.7
14.1


Total Runtime Area
21.8
76.2
82.4
83.9










Percent Difference from
249.9%
278.3%
285.1%


Standard









Testing Results:
Results show that 1000 μL, of oil based defoamer was needed to match the performance of polymeric defoamer, 265-66-2, containing the acrylate/acrylic acid polymer. This represents a five-fold increase in defoamer dosage over the experimental polymeric defoamers.
Example 8
Silicone Emulsion Defoamer Testing
The different polymers were tested in a silicone emulsion in an attempt to measure the affect of the polymer on performance. Below are the formulations and results from the testing.







TABLE 32







Silicone Emulsion Formulations*














265-
265-
265-






95-1
95-2
95-3
265-96-1
265-96-2
265-96-3
















Silicone
99
99
99
98
98
98


Emulsion








Acrylate
1


2




Polymer








in DIDP








Acrylate

1


2



Polymer








in DIOA








8 Mol %


1


2


Acrylic








Acid





*Polymers were added into the formulation during product manufacture, not as a post-add.













TABLE 33







Results from Silicone Emulsion Testing














265-95-1
265-95-2

265-96-1
265-96-2




1%
1%

2%
2%




Acrylate
Acrylate
265-95-3
Acrylate
Acrylate
265-96-3



Polymer
Polymer
1%
Polymer
Polymer
2%



in DIDP
in DIOA
8 Mol %
in DIDP
in DIOA
8 Mol %



Avg
Avg
Avg
Avg
Avg
Avg
















1st 30
8.6
9.1
8.1
8.8
7.2
8.3


Seconds Area








Total
36.6
41.2
27.6
37.8
22.2
20.3


Runtime Area


















Percent Difference
12.4%
−24.7%
3.1%
−39.5%
−44.6%


from Standard









Testing Results:
Testing shows that increasing the amount of polymer in the silicone emulsion formulation decreases performance with polymer, 265-96-3, containing 8 mol % acrylic acid having the poorest performance.
Silicone Concentrate Testing:
The different polymers were examined in a silicone concentrate defoamer at 3, 6, and 10%. Below are the formulations and results from the testing.







TABLE 34







Silicone Concentrate Defoamer Formulations




















265-
265-
265-
265-
265-
265-



265-97-2
265-97-3
265-97-4
97-5
97-6
97-7
97-8
97-9
97-10



















Generic
97
97
97
94
94
94
90
90
90


Silicone











Defoamer











Base:











Acrylate
3


6


10




Polymer in











DIDP











Acrylate

3


6


10



Polymer in











DIOA











8 Mol %


3


6


10


Acrylic











Acid





*Polymer was post-added to the silicone defoamer and mixed for 10 minutes.













TABLE 35





Results from Silicone Concentrate Testing







Table 35A












265-97-2
265-97-3

265-97-5



3%
3%

6%



Acrylate
Acrylate
265-97-4
Acrylate



Polymer in
Polymer in
3%
Polymer in



DIDP
DIOA
8 Mol %
DIDP





1st 30
9.3
8.9
8.7
9.9


Seconds






Area






Total
27.4
25.5
17.3
29.6


Runtime






Area














Percent Difference from
−0.1
−0.4
0.1


Standard










Table 35B













265-97-6

265-97-8
265-97-9




6%

10%
10%




Acrylate
265-97-7
Acrylate
Acrylate
265-97-10



Polymer
6%
Polymer
Polymer
10%



in DIOA
8 Mol %
in DIDP
in DIOA
8 Mol %





1st 30
9.5
10.2
8.5
8.5
9.9


Seconds







Area







Total
24.6
18.3
21.0
17.2
15.1


Runtime







Area







Percent
−0.1
−0.3
−0.2
−0.4
−0.4


Difference







from







Standard









Testing Results:
Testing shows that varying the polymers in different silicone defoamer concentrations have no effect on performance.
Example 9
Methacrylic Acid Addition
Reactions were completed where the acrylic acid was replaced with methacrylic acid. The procedure for manufacturing the polymer was the same as with the acrylic acid (see Example 6 above). The methacrylic acid was added to the Acrylate polymer at 8 mol %. The resulting polymer has the numerical designation 296-4. The polymer was clear, with a viscosity of 27,750 cps as measured by a Brookfield RVT viscometer, spindle 6, speed 60. The methacrylic acid polymer was then tested in the polymeric defoamer formulation as a direct substitution. Below are the formulations tested and the results from the testing.







TABLE 36







Polymeric Formulations Containing 23.5% Polymer












265-100-4
265-100-5
265-100-6
296-6















Polypropylene
31.5
31.5
31.5
31.5


Glycol


10%
30
30
30
30


Hydrophobic


Silica in


Polypropylene


Glycol


Polyether-
10
10
10
10


Modified


Polysiloxane


Silicone


Surfactant


Alkyl Modified
5
5
5
5


Siloxane Silicone


Wax


Acrylate Polymer
23.5


in DIDP


Acrylate Polymer

23.5


in DIOA


8 Mol % Acrylic


23.5


Acid


8 Mol %



23.5


Methacrylic Acid
















TABLE 37







Results from Polymeric Defoamer Testing












265-100-4
265-100-5





Acrylate
Acrylate
265-100-6
296-6



Polymer
Polymer in
8 Mol %
8 Mol %



in DIDP
DIOA
Acrylic
Methacrylic



Avg
Avg
Avg
Avg















1st 30
4.2
4.3
5.3
6.0


Seconds


Area


Total
25.5
28.8
32.5
34.4


Runtime


Area










Percent Difference
12.9%
27.6%
34.9%


from Standard









Testing Results:
Testing of the polymeric defoamers containing 23.5% polymer shows the addition of polymer 296-6, containing 8 mol % methacrylic acid, increases performance when compared to the use of the Acrylate polymer in DIDP, the Acrylate polymer in DIOA, or the polymer containing 8 mol % acrylic acid.
Example 10
Preparation of Methacrylate Polymers
After showing that substitution of methacrylic acid for acrylic acid in the acrylate polymer leads to an increase in defoamer performance, experiments were completed that replaces all of the acrylate monomers with the methacrylate analogs, as well as the acrylic acid with methacrylic acid. The methods and procedures of Example 1 were used to produce the polymers.
In the first experiment, 250 g of DIOA was placed into a reaction flask. A vacuum was applied for 20 minutes to remove dissolved air. The DIOA was sparged with nitrogen while being heated to 79-82° C. with mixing. Once at temperature and with the nitrogen sparge and constant mixing, 1.5 g of a free radical generating compound was added and allowed to dissolve over a 5 minute period. Meanwhile, 33.22 g of 2-hydroxyethyl methacrylate, 153.22 g of 2-ethylhexyl methacrylate, and 13.56 g of methacrylic acid were pre-mixed in a beaker. The mixture was added to the DIOA diluent through an addition funnel at a rate of approximately 1.0 g/minute, making sure to maintain a temperature of approximately 79-82° C. After 25 minutes, the mixture began to cloud. After 1.5 hours, the mixture in the reaction flask was viscous enough to overload the mixer. The mixer was replaced, but the mixture was too thick to stir. The heat was turned off. 42.2 g of the monomer mixture was present in the addition tube, leading to 157.8 g of monomer mixture in the reaction flask. The resulting polymer was allowed to cool. The polymer was solid at room temperature.
A second experiment was completed with a more dilute monomer concentration to allow for the reaction to run to completion while still being able to mix the resultant polymer. Again, the methods and procedures of Example 1 were used to produce the polymers.
250 g of DIOA was placed into a reaction flask. A vacuum was applied for 20 minutes to remove dissolved air. The DIOA was sparged with nitrogen while being heated to 79-82° C. with mixing. Once at temperature and with the nitrogen sparge and constant mixing, 1.5 g of a free radical generating compound was added and allowed to dissolve over a 5 minute period. Meanwhile, 8.79 g of 2-hydroxyethyl methacrylate, 40.56 g of 2-ethylhexyl methacrylate, and 3.59 g of methacrylic acid were pre-mixed in a beaker. The mixture was added to the DIOA diluent through an addition funnel at a rate of approximately 1.0 g/minute, making sure to maintain a temperature of approximately 79-82° C. After the monomer mixture was added, the addition funnel and tube was rinsed with 48 g of DIOA, and then 0.5 g of free radical generating compound was added. Another 0.5 g of free radical generating compound was added, and the mixture was held at 79-82° C. with mixing and nitrogen for 2 hours. The mixture was then air cooled to room temperature. The resulting polymer was a cloudy liquid with a viscosity of 400 cps. The numeric designation for this product is 296-14.
Performance testing of polymer, 296-14, was completed against formulations 296-15-1,2,4, and 5, shown below in Table 38. The polymers were formulated into polymeric defoamers, and the defoamers were tested in 100% black liquor at 82° C. Below are the formulations and results from the testing.







TABLE 38







Polymeric Defoamer Formulations













296-



296-



15-1
296-15-2
296-15-3
296-15-4
15-5















Polypropylene
25
25
25
25
25


Glycol







10%
30
30
30
30
30


Hydrophobic







Silica in







Polypropylene







Glycol







Acrylate
11.3






Polymer in







DIDP







Acrylate

11.3





Polymer in







DIOA







296-14


30




8 Mol % Acrylic



11.3



8 Mol %




11.3


Methacrylic







Polyether-
10
10
10
10
10


Modified







Polysiloxane







Silicone







Surfactant







Alkyl Modified
5
5
5
5
5


Siloxane







Silicone Wax







DIOA
18.8
18.8

18.8
18.8
















TABLE 39







Results from Testing the Methacrylate/Methacrylic


Acid Polymer.













296-15-3



296-15-1
296-15-2
Methacrylate/



Acrylate
Acrylate
Methacrylic



Polymer
Polymer
Acid



in DIDP
in DIOA
Polymer














1st 30 Seconds Area
5.9
5.7
6.9


Total Runtime Area
31.7
31.2
46.9










Percent Difference from

−1.5%
48.1%


Standard









Testing Results:
Testing shows that a polymer comprising hydroxyalkyl methacrylate, alkyl methacrylate, and methacrylic acid, when formulated into defoamer 296-15-3, provides increased initial air removal and increased longevity when compared to polymers 296-15-1 and 2, consisting of hydroxyalkyl acrylate and alkyl acrylate. A defoamer formulation containing the above polymer, 296-14, outperforms defoamer formulations 296-15-1 and 2 by as much as 48%.
SUMMARY AND CONCLUSIONS
The potential benefits of a defoamer that contains an alkyl acrylate/hydroxyalkyl acrylate/acrylic acid polymer are clearly demonstrated herein. Notable improvements in initial performance and longevity were realized by incorporating the polymer into a formulation containing polypropylene glycol, hydrophobic silica, and silicone surfactants. This approach is new in terms of defoamers used in industrial settings.
The use of monomers other than alkyl acrylate/hydroxyalkyl acrylate/acrylic acid that may be used to produce a polymer that provides increased defoaming performance has been demonstrated herein. The alternate monomers may include methacrylic acid, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, and the butyl analogs of the acrylates and methacrylates.
The final formulations for use will be determined based on the operating parameters of a given application, i.e. the alkalinity, temperature, and the need for dispersibility. The final product(s) will be tailored for individual needs.
All patents, patent applications and publications cited in this application are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual patent, patent application or publication were so individually denoted.
Although certain embodiments and examples have been described in detail above, those having ordinary skill in the art will clearly understand that many modifications are possible in the embodiments and examples without departing from the teachings thereof. All such modifications are intended to be encompassed within the below claims of the invention.

## Claims

1. A defoamer formulation comprising 0.01 to 50% by weight of an acrylate polymer with 1-20 mol % acrylic acid in a suitable diluent, based on a total weight of the formulation, 20-80% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation, 0.01 to 15% by weight of an additive, based on a total weight of the formulation, and optionally, 0.01 to 30% by weight of a surfactant, based on a total weight of the formulation.

2. The defoamer formulation of claim 1, wherein the acrylate polymer comprises acrylate monomers of the following general formula:



R is hydrogen or a linear or a branched alkyl group comprising from about 1 to 18 carbon atoms and optionally at least one hydroxy group.

3. The defoamer formulation of claim 2, wherein the acrylate polymer is a product of a polymerization reaction between 2-ethylhexyl acrylate monomer, 2-hydroxyethyl acrylate monomer, and acrylic acid monomer.

4. The defoamer formulation of claim 1, comprising 20-30% by weight hydroxyalkyl/alkyl acrylate polymer with 8 mol % acrylic acid monomer, based on a total weight of the formulation.

5. The defoamer formulation of claim 1, wherein the suitable diluent is selected from diisodecyl phthalate, diisooctyl adipate, bis-2-ethylhexyl adipate, dioctyl adipate, 2-ethyl-1-hexanol, isooctyl alcohol, dihexyl phthalate, or mixtures thereof.

6. The defoamer formulation of claim 5, wherein the suitable diluent is diisoctyl adipate.

7. The defoamer formulation of claim 1, comprising 40-60% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation.

8. The defoamer formulation of claim 1, comprising 3-10% by weight of an additive, based on a total weight of the formulation.

9. The defoamer formulation of claim 1, wherein the additive is selected from hydrophobic silica, waxes, fatty alcohols, fatty acids, or mixtures thereof.

10. The defoamer formulation of claim 9, wherein the additive is hydrophobic silica.

11. The defoamer formulation of claim 1, comprising 10-15% by weight surfactants, based on a total weight of the formulation.

12. The defoamer formulation of claim 1, wherein the surfactant is selected from polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol,alkoxylated dimethylpolysiloxane, alkyl modified siloxanes, fluorine modified siloxanes, mercapto modified siloxanes, hydroxy modified siloxanes, siloxane wax, ethylene oxide/propylene oxide block copolymer, the esters of polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol, ethylene oxide/propylene oxide block copolymer, alkylpolyoxyethylene ethers, alkylpolyoxyethylenes, polyoxypropylene ethers, fatty acid polyoxyethylene esters, fatty acid polyoxyethylene sorbitan esters, fatty acid polyoxypropylene sorbitol esters, polyoxyethylene castor oils, alkylpolyoxyethylene amines and amides, fatty acid sorbitan esters, fatty acid polyglycerin esters, fatty acid sucrose esters, or mixtures thereof.

13. The defoamer formulation of claim 12, wherein the surfactant is a siloxane wax.

14. The defoamer formulation of claim 1, comprising 23.5% by weight acrylate polymer with 8 mol % acrylic acid in diisooctyl adipate, based on a total weight of the formulation, 51.5% by weight polypropylene glycol, based on a total weight of the formulation, 10% by weight hydrophobic silica, based on a total weight of the formulation, and 15% by weight siloxane wax, based on a total weight of the formulation.

15. A defoamer formulation comprising 0.01 to 50% by weight of a methacrylate polymer with 1-20 mol % methacrylic acid in a suitable diluent, based on a total weight of the formulation, 20-80% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation, 0.01 to 15% by weight of an additive, based on a total weight of the formulation, and optionally, 0.01 to 30% by weight of a surfactant, based on a total weight of the formulation.

16. The defoamer formulation of claim 15, wherein the methacrylate polymer comprises methacrylate monomers of the following general formula:



R is hydrogen or a linear or a branched alkyl group comprising from about 1 to 18 carbon atoms and optionally at least one hydroxy group.

17. The defoamer formulation of claim 16, wherein the methacrylate polymer is a product of a polymerization reaction between 2-ethylhexyl methacrylate monomer, 2-hydroxyethyl methacrylate monomer, and methacrylic acid monomer.

18. The defoamer formulation of claim 15, comprising 20-30% by weight hydroxyalkyl/alkyl methacrylate polymer with 8 mol % methacrylic acid monomer, based on a total weight of the formulation.

19. The defoamer formulation of claim 15, wherein the suitable diluent is selected from diisodecyl phthalate, diisooctyl adipate, bis-2-ethylhexyl adipate, dioctyl adipate, 2-ethyl-1-hexanol, isooctyl alcohol, dihexyl phthalate, or mixtures thereof.

20. The defoamer formulation of claim 19, wherein the suitable diluent is diisooctyl adipate.

21. The defoamer formulation of claim 15, comprising 40-60% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation.

22. The defoamer formulation of claim 15, comprising 3-10% by weight of an additive, based on a total weight of the formulation.

23. The defoamer formulation of claim 15, wherein the additive is selected from hydrophobic silica, waxes, fatty alcohols, fatty acids, or mixtures thereof.

24. The defoamer formulation of claim 23, wherein the additive is hydrophobic silica.

25. The defoamer formulation of claim 15, comprising 10-15% by weight surfactants, based on a total weight of the formulation.

26. The defoamer formulation of claim 15, wherein the surfactant is selected from polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol,alkoxylated dimethylpolysiloxane, alkyl modified siloxanes, fluorine modified siloxanes, mercapto modified siloxanes, hydroxy modified siloxanes, siloxane wax, ethylene oxide/propylene oxide block copolymer, the esters of polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol, ethylene oxide/propylene oxide block copolymer, alkylpolyoxyethylene ethers, alkylpolyoxyethylenes, polyoxypropylene ethers, fatty acid polyoxyethylene esters, fatty acid polyoxyethylene sorbitan esters, fatty acid polyoxypropylene sorbitol esters, polyoxyethylene castor oils, alkylpolyoxyethylene amines and amides, fatty acid sorbitan esters, fatty acid polyglycerin esters, fatty acid sucrose esters, or mixtures thereof.

27. The defoamer formulation of claim 26, wherein the surfactant is a siloxane wax.

28. The defoamer formulation of claim 15, comprising 30% by weight methacrylate polymer with 8 mol % methacrylic acid, based on a total weight of the formulation, 45% by weight polypropylene glycol, based on a total weight of the formulation, 10% by weight hydrophobic silica, based on a total weight of the formulation, and 15% by weight siloxane wax, based on a total weight of the formulation.

29. A method of reducing or preventing the generation of foam, comprising adding the defoamer formulation of claim 1 before, during, or after said foam is generated.

30. A method of reducing or preventing the generation of foam, comprising adding the defoamer formulation of claim 15 before, during, or after said foam is generated.

31. A method for preparing the defoamer formulation of claim 1 comprising mixing 0.01 to 50% by weight of an acrylate polymer with 1-20 mol % acrylic acid in a suitable diluent, based on a total weight of the formulation, 20-80% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation, 0.01 to 15% by weight of an additive, based on a total weight of the formulation, and optionally, 0.01 to 30% by weight of a surfactant, based on a total weight of the formulation.

32. A method for preparing the defoamer formulation of claim 15 comprising mixing 0.01 to 50% by weight of a methacrylate polymer with 1-20 mol % methacrylic acid in a suitable diluent, based on a total weight of the formulation, 20-80% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation, 0.01 to 15% by weight of an additive, based on a total weight of the formulation, and optionally, 0.01 to 30% by weight of a surfactant, based on a total weight of the formulation.