WO2002034796A1

WO2002034796A1 - Aqueous dispersions of a water soluble polymer, method for preparing same, and uses thereof

Info

Publication number: WO2002034796A1
Application number: PCT/FR2001/003262
Authority: WO
Inventors: René Hund; Didier Cochin
Original assignee: Snf S.A.
Priority date: 2000-10-23
Filing date: 2001-10-19
Publication date: 2002-05-02
Also published as: FR2815635B1; FR2815635A1; AU2002214086A1

Abstract

The invention concerns a method for preparing an aqueous dispersion of a polymer for limiting variations of viscosity of the reaction mixture during the entire polymerising process. Said method most unexpectedly results in aqueous dispersions exhibiting high content of active material, good stability and good fluidity, without giving rise to specific dispersant, and in using standard industrial installations similar to those used for inverse emulsions. The invention also concerns the resulting polymers and their industrial use, in particular in the paper, oil, water treatment, mining, cosmetics, textile industries and generally in all technical industrial techniques requiring the use of water soluble polymers.

Description

Aqueous dispersions of a water-soluble polymer, process for their preparation, and their applications.

The invention relates to the technical sector of water-to-water dispersions and in particular to aqueous dispersions of water-soluble polymers.

The dispersions are obtained by polymerization in an aqueous solution of a mixture of monomers in the presence of a water-soluble polymer (called dispersant or coagulant) and optionally a salt.

A first type of dispersion has been described by US patent 4,380,600. The dispersions are obtained by polymerization of a mixture of water-soluble monomers in the presence of a water-soluble polymer of the po! Y type (ethylene glycol), poly (ethylene imine), sodium polyacrylate, soluble starches, etc.

Following this invention, two main lines of research were explored:

One of the methods is described in patent CA 2,096,471 (Rohm). In this process, an aqueous dispersion is obtained by polymerization of a mixture comprising a water-soluble monomer, a hydrophobic monomer and an amphiphilic monomer in the presence of a polymeric coagulant present in a significant proportion (> 10% by weight and in general of l '' around 15%).

In addition to the Rohm process, characterized by the absence of salt in the reaction mixture, US Pat. No. 4,929,655 (Hymo) constitutes one of the very first patents which gave rise to industrial development. In this process, an aqueous dispersion is obtained by precipitation polymerization of a mixture of water-soluble monomers containing at least one hydrophobic monomer of the acryloyloxyethyldimethylbenzyl ammonium chloride type in an aqueous saline solution in the presence of a dispersant (<5% by weight and generally <2%).

The main technical problems encountered by the industry for this type of polymerization and inherent in the processes described above are:

viscosity problems: the water-soluble polymer formed during a polymerization in aqueous dispersion will tend to dissolve, which will cause an increase in the viscosity of the reaction mixture (risk of runaway reaction) as well as '' a decrease in the fluidity of the final product. - stability problems: the polymer particles formed tend to stick together and to solidify both during polymerization and during storage.

The prior art

It is well known to those skilled in the art that the process described in US Pat. No. 4,929,655 (HYMO) leads to high viscosities during the polymerization, necessitating either the use of reactors specific to the implementation of such mixtures and / or or the limitation of the level of active material in the dispersion (<15% by weight). In addition, this document covers an extremely precise and limited combination.

In the prior art, there have been numerous evolutions made in an attempt to overcome this problem. We will quote:

Patent EP 0 657 478 (NALCO) aims to overcome this drawback by adding salt at an initial and constant concentration of between 17 to 19%. This rate is described as being optimum for polymerizing systems of monomers similar to those described in US Pat. No. 4,929,655; however, the salt contents remain high and the viscosities encountered during polymerization are none the less high.

With a view very close to the Hymo patent, patent WO 98/14405 (CYTEC) describes in particular the use of a mixture consisting of a chaotropic salt and possibly a kosmotropic salt (according to the Hofmeister series) or a salt organic and a water-soluble polymer as a medium precipitating from the dispersion.

In a comparable manner, patent EP 0 637 598 (NALCO) relates to the use of a dispersant obtained by copolymerization of DADMAC with a compound of the hydrophobic quaternary ammonium type prepared from dialkylaminoacrylais or dialkylaminomethacrylates or alkyl esters of acrylic acid.

An alternative for reducing the viscosity of the reaction mixture during the polymerization is reported in patent EP 0 630 909 (NALCO). It consists in adding a fraction of the monomer mixture during the polymerization. Finally, patent WO 98/31749 (Allied Colloids) is also similar to patent CA 2,096,471 (Rohm) in that it combines a flocculant and a coagulant. The use of a hydrophobic monomer is not necessary and this process differs from Rohm's patent in that it requires the presence of a salt. As with patent CA 2,096,471 (Rohm), the level of flocculant remains low and of the order of 10% while the level of coagulant remains high and of the order of 20%.

Description of the invention

For dispersions prepared in the presence of salt, it is well known that the addition of an additional fraction of salt to the final dispersion (after polymerization) makes it possible on the one hand to fluidize the latter and on the other hand to improve its stability by adjusting the density of the continuous phase to that of the polymer particles. Surprisingly and contrary to the observations developed in patent EP 0 630 909 (p 5, 1 29-32), it has been discovered that, for identical conditions and formulations, the addition of salt fractionally - at least one part before polymerization and the remainder in one or more additional successive fractions at the start of polymerization - more precisely, preferably but not limited to, during the first third or preferably the first quarter of the total polymerization time, makes it possible to improve optimally the fluidity of the reaction mixture during polymerization by limiting and optimizing the variations in viscosities.

Thanks to these sequential additions in the first part of the polymerization (after addition of the catalyst), carried out in the form of one or more salt fractions in addition to the amount introduced into the initial formulation (before polymerization), it is possible surprisingly, to obtain aqueous dispersions of polymers having good fluidity throughout the polymerization process, a high level of active material (> 15% and up to 30%) and having good stability, in a very wide range. large molecular weight, and thus allowing the use of standard industrial installations identical to those used for reverse emulsions.

The term ^"part 1 of the polymerization" the period after the boot covering the first third of the total time of polymerization, preferably the first quarter, of the total polymerisation time after initiation. By "active ingredient" is meant throughout the present application the true fraction of flocculant, with the exception of the coagulant and / or dispersant fractions. According to a preferred embodiment of the invention, the additional successive fraction (s) of salt are indeed added during the first 1/4 of the total polymerization time after initiation.

The successive salt fraction (s) added during the polymerization represent a rate of about 1 to 50% by weight relative to the total amount present in the mixture during the polymerization. In a preferred embodiment of the invention, the salt fraction (s) added during the polymerization represent a total of approximately 5 to 50% by weight relative to the total quantity of salt present in the mixture, and preferably of approximately 10 at 40%.

This process is also characterized in that the level of water-soluble polymer (dispersant) present with the salt remains low and is less than 5% by total weight of the dispersion and preferably less than 3%.

The present invention relates more precisely to the methods which have just been described and to their embodiments and variants.

The present invention also covers: the polymers and copolymers obtained by the methods described; the application in the industry of the polymers and copolymers described; non-limiting mention will be made of: the paper industry (retention, draining, etc.), water treatment (drinking or used), in general all coagulation / flocculation techniques, the mining industry, the industry petroleum and refining, the cosmetics industry, the textile industry, and all similar applications which will be obvious to the skilled person.

The present invention also applies to, and covers, all types of nonionic, anionic, cationic or amphoteric polymers and copolymers obtained by the processes described, both linear and slightly or strongly branched, or crosslinked (by a proportion of 'crosslinking agent), and their applications as already mentioned.

It will be noted that, from their origin, water-to-water dispersions have been developed to complete the range of standard water-in-oil emulsions and that, the applications in industry of these 2 types of emulsions, comprising polymers of similar nature, are, obviously, the same. The dispersions of the invention are obtained by polymerization in an aqueous solution of a mixture of monomers in the presence of one or more water-soluble polymer (s) (called dispersant (s) or coagulant (s)) and possibly a salt.

MONOMERS

Without limitation, the following monomers and their combinations may be used.

Nonionic monomers: the nonionic monomers useful according to the invention can be chosen from vinyl monomers soluble in water. Preferred monomers belonging to this class include acrylamide and methacrylamide, acrylamide derivatives such as N-alkylaerylamide for example N-isopropylacrylamide, N-tert-butylacrylamide, octylacrylamide as well as NN-dialkylacrylamides such as NN -dimethylacrylamide and N-methylolaciylamide. Also vinylformamide, N-vinylpyridine, Nr vinylpyrrolidone, hydroxyalkyl acrylates and methacrylates can be used. A preferred nonionic vinyl monomer will be acrylamide. Other nonionic monomers can be used, without departing from the scope of the invention, in particular hydrophobic monomers: styrene, alkyl (meth) acryiate and aryl (meth) acrylate.

Anionic Monomers: The anionically charged monomers useful in the present invention can be selected from a large group. The monomers can have acrylic, vinyl, maleic, fumaric functionalities. allylics and contain a carboxy, phosphonate, sulfonate, or other anionically charged group, or the corresponding ammonium or alkaline earth metal or alkali metal salt of such a monomer. Examples of suitable monomers include acrylic acid, methacrylic acid, acrylamidomethylpropanesulfonic acid, acrylamidomethylbutanoic acid, maleic acid, fumaric acid, itaconic acid, vinyisulfonic acid, styrene acid sulfonic, vinylphosphonic acid, allylsulfonic acid, allylphosphonic acid and their water-soluble salts of an alkali metal, an alkaline earth metal, and ammonium. Cationic monomers

As cationic monomers, those corresponding to the following formula may be used: CH2 = C - R1 R2

0 = C - A1 - B1— N + - R4 ^{x "}

I R3

in which R _ι represents H or CH ₃ ; R ₂ and R ₃ represent C alkyl groups _. -C ₃ ; ^R represents H or an O, -C ₂₂ alkyl group or an (alkyl) aryl group or a substituted aryl group; A ₁ represents an oxygen atom or NH; B., represents a C ₂ -C ₁₀ alkylene group or a hydroxypropylene group, and X ^~ is an anionic counter ion. Cationic monomers such as derivatives of diallyldialkylammonium halides can also be used.

SALT

Any organic or inorganic salt allowing the insolubilization of the prepared polymer can be used according to the invention. Preferred salts are those comprising the sulfate, dihydrogen phosphate, phosphate and halide anions. The corresponding cations can be sodium, potassium, ammonium, magnesium, aluminum. The simultaneous use of two or more of these salts is also possible.

DISPERSING

As dispersants are effective a polymer electrolyte and / or a polyol and / or derivatives of carbohydrates soluble in an aqueous saline solution. The use of a single dispersant or a mixture of dispersants is also possible.

Without limitation, the preferred dispersing polymers are:

For dispersions of anionically charged polymers: the particularly preferred dispersing polymers are homopolymers and copolymers obtained from 2-acrylamido-2-methyl-1-propane sulfonic acid or its salts or acid (meth) acrylic or its salts and the copolymers obtained from these monomers and from the aforementioned nonionic monomers.

For dispersions of polymers with a cationic charge: the particularly preferred dispersing polymers are polyamines, such as, for example, polymers resulting from the condensation of epichlorohydrin and dimethylamine, homopolymers and copolymers obtained from one or more monomers ( s) cationic; as cationic monomers, examples that may be mentioned include quaternized derivatives of N, N-dimethylamino ethyl (meth) acryiate, N, N-dimethylamino propyl (meth) acrylate, N, N-dimethylamino propyl (meth) acrylamide or N, N-dimethylamino hydroxypropyl (meth) acrylate or diallyldialkylammonium halides, and the copolymers obtained from these monomers and from the aforementioned nonionic monomers.

As particularly preferred dispersing polymers, mention may also be made of polyalkylene ethers, for example polyethylene glycol, polypropylene glycol or the homopoiymer of 2-acrylamido-2-methyl-1-propane sulfonic acid, polydiallyldimethylammonium chloride (poly-DADMAC) and / or polyacryloyloxyethyltrimethyl ammonium chloride and their derivatives.

Certain additives known to those skilled in the art can also be used. Without limitation, mention will be made of glycerol, ethylene glycol, propylene glycol, etc.

EXAMPLES

The viscosities are Brookfield viscosities measured with the LV 2, 3 or 4 modules and at the speed of 60, 30 or 12 revolutions per minute depending on the polymers.

Example 1:

Copolymer AM / ADC / ADBZ 65/8/27: active ingredient: 20%

In a 1 l reactor equipped with a stirrer, a thermometer, a condenser and a nitrogen inlet, the following are introduced:

Monomers _. ; - _, 137.17g of acrylamide (AM) at 50%, 28.75g of acryloyloxyethylltrimethylmammonium chloride (ADC) at 80%, 135.52g of acryloyloxyethyldimethylbenzylammonium chloride (ADBZ) at 80% The dispersant: 74.3 g of a 20% aqueous solution of diallyldimethyl ammonium chloride homopolymer (polyDADMAC).

Salt: 127.15g of ammonium sulfate with 6.14g of glycerol and 469.55g of water. The mixture is heated to 38 ° C. and degassed with nitrogen for 1/2 hour. Then an azo type initiator such as VA044 ™ (start of polymerization) is added. The temperature is maintained at 38 ° C. Ammonium sulphate fractions of 7.14 g are added 40 min, 1h20 and 2h after the addition of the initiator. A new fraction of azo initiator (identical or different from that used during priming) is introduced after 5 h 30 of polymerization. The polymerization is complete after 8:30 of reaction.

VA 044 ™ is a compound of the 2,2'-Azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride type marketed by WAKO Company.

Example 2: Same as Example 1 except that ^! The entire fraction of the ammonium salt is introduced into the initial formulation.

Example 3:

Identical to Example 1 except that 21.42 g of salt are introduced after 1 hour 15 minutes of polymerization.

Example 4:

Identical to Example 1 except that 21.42 g of salt are introduced after 3 hours of polymerization.

Example 5:

Identical to example 1 except that 21.42 g of salt are introduced at the end of polymerization. The peak viscosities obtained during the polymerization of the mixtures for Examples 1 to 5 were recorded in Table 1. Table 1

NF: number of additional fractions added fractionally after initiation of the polymerization.

Conclusion:

Very high maximum viscosities are observed when all of the ammonium sulphate is introduced into the initial formulation (ex. 2) or when an additional fraction of ammonium sulphate is introduced at the end (ex. 5) or after 3 hours of polymerization (ex. 4).

For an identical total amount of salts, the addition of a single fraction of ammonium sulfate at the start of polymerization (ex. 3) makes it possible to improve the fluidity of the mixture, the latter being able to be further improved by the successive addition several salt fractions in the first part of the polymerization (ex. 1) defined above.

The variation in the viscosity of the reaction mixture during the polymerization as a function of time is shown in the single FIGURE for Examples 1, 2 and 4.

It is noted that the advantage of the invention lies in that it makes it possible to maintain a very low viscosity level throughout the polymerization while avoiding variations and increases in viscosity of the reaction mixture, which makes it possible to eliminate the problems. solidification and the risk of runaway reaction linked to exchange problems in a highly viscous medium which are inherent in other polymerization processes as described in the prior art.

Example 6: Same as Example 1 except for the dispersant:

81g of a 20% aqueous solution of poly (ADC) (replacing poly (DADMAC)) and 462.58g of water. Maximum viscosity of the dispersion: 1100 cp

Example 6 shows that all the advantage of the invention is preserved whatever the type of dispersant used.

Example 7:

Copolymer AM / ADBZ 90/10: active material: 20% Identical to example 1 with the exception of the monomers: 281.13g of acrylamide at 50%, 74.30g of acryloyloxyethyldimethyl benzylammonium chloride at 80% and 415.56g d 'water. Maximum dispersion viscosity: 1500 cp

Example 8:

Copolymer A / ADC / ADBZ 25/27/48: active material: 20% Identical to example 1 with the exception of the monomers:

35.56g of 50% acrylamide, 65.40g of acryloyloxyethyl chloride. 80% trimethymammonium, 162.38g of acryloyloxyethyldimethyl benzyl ammonium chloride at 80% and 507.65g of water. Maximum dispersion viscosity: 760 cp

Examples 1, 7 and 8 show that polymer dispersions can be prepared in a wide range of ionicity according to the process of the invention while retaining good fluidity.

Example 9:

Copolvmère AM / ADC / ADBZ 50/15/35; active material: 25% Identical to example 1 with the exception of the monomers:

111, 57g of 50% acrylamide, 57,00g of acryloyloxyethyl triméthymammonium to 80%, 185,76g of ammonium chloride acryloyloxyéthyldiméthyibenzyl 80% and 416,65g ^'water. Maximum dispersion viscosity: 1800 cp

Example 10:

Copolymer AM / ADC / ADBZ 50/15/35: active material: 30% Identical to example 1 with the exception of the monomers:

133.89g of 50% acrylamide, 68.40g of 80% acryloyloxyethylltrimethymammonium chloride, 222.92g of 80% acryloyloxyethyldimethylbenzyl ammonium chloride and 345.78g of water. Maximum dispersion viscosity: 2900 cp

Examples 1, 9 and 10 show that the dispersions of the invention can be carried out with high levels of active material (> 25%).

Example 11:

AM / acrylic acid 70/30 copolymer; active ingredient: 18%

The following are introduced into a reactor of 11 equipped with a stirrer, a thermometer, a condenser and a nitrogen inlet: Monomers: 250.94g of 50% acrylamide, 54.50g of acrylic acid The dispersant: 7.1 g of a homopolymer of aerylamidomethylpropane sulfonic acid

Salts 60g of sodium sulfate and 72g of ammonium sulfate with 4.83g of 50% sodium hydroxide, 18g of glycerol and 507.13 of water. The mixture is heated to 38 ° C. and degassed with nitrogen for 1/2 hour. We then add an azo type initiator te! than VA044 (start of polymerization). The temperature is maintained at 38 ° C. 8.5g ammonium sulfate fractions are added after 25min, 40min and 1h15.

A new fraction of azo initiator (identical or different from that used during priming) is introduced after 3 hours of polymerization. The polymerization is complete after 4 h 30 of reaction. Maximum dispersion viscosity: 480 cp

Example 12: Identical to Example 11 except that the entire fraction of ammonium sulphate is introduced into the initial formulation. Maximum dispersion viscosity: 3900 cp

It is noted (ex. 11 & 12) that the process of the invention also makes it possible to improve the fluidity of dispersions of polymers comprising an anionic charge.

In conclusion, the various examples produced according to the process of the invention, which illustrate it without however limiting it, present the improvements obtained relating to the fluidity of the reaction mixture! during the polymerization process leading to stable final dispersions (with low salt contents).

Claims

1 Process for the polymerization of a monomer or a mixture of monomers

5 in an aqueous solution in the presence of one or more water-soluble polymer (s) (called dispersant (s) or coagulant (s)) and a salt or a mixture of salts, characterized in what is done adding the salt fractionally - a part before polymerization and a part in at least one or more additional successive fractions during the first part of the polymerization. More specifically, o preferably but not limiting, the term ^"part 1 of the polymerization" the period after the boot covering the first third of the total time of polymerization, preferably the first quarter, relative at the total polymerization time after initiation.

2 Method according to claim 1 characterized in that the block additions in the first part of the polymerization (after addition of the catalyst), carried out in the form of one or more salt fractions in addition to the amount introduced in the initial formulation (before polymerization), lead to aqueous dispersions of polymers having good fluidity throughout the polymerization process, a high level of active material (> 15% and up to 30%) and having good stability, in a range very broad molecular weights. The term ^"part 1 of the polymerization" the period after the boot covering the first third of the total time of polymerization, preferably the first quarter, of the total polymerisation time after initiation.

3 Method according to claim 1 or 2 characterized in that the fraction (s). additional successive stages of salt are added during the first 1/4 of the total polymerization time after initiation.

4 Method according to any one of claims 1 to 3 characterized in that the successive fraction or fractions of salt added during polymerization represent a rate of about 1 to 50% by weight relative to the total amount present in the mixture during the polymerization, preferably about 5 to 50% by weight and more preferably about 10 to 40%. 5 Method according to any one of claims 1 to 4 characterized in that the rate of water-soluble polymer (dispersant) present with the salt remains low and is less than 5% by total weight of the dispersion and preferably less than 3%.

6 Method according to any one of claims 1 to 5 characterized in that one can use the following monomers and their combinations.

Nonionic monomers

The nonionic monomers useful according to the invention can be chosen from vinyl monomers soluble in water. Preferred monomers belonging to this class include acrylamide and methacrylamide, acrylamide derivatives such as N-alkylacylamide, for example N-isopropylacrylamide, N-tert-butylacrylamide, Poctylacrylamide as well as N, N-diaIkylacrylamides such as NN-dimethylacrylamide and N-methylolacrylamide. Also vinylformamide, N-vinyIpyridine, N-vinyipyrrolidone, hydroxyalkyl acrylates and methacrylates can be used. A preferred nonionic vinyl monomer will be acrylamide. Other nonionic monomers can be used, without departing from the scope of the invention, in particular hydrophobic monomers: styrene, alkyl (meth) acrylate and aryl (meth) acrylate.

Anionic monomers

The anionically charged monomers useful in the present invention can be selected from a large group. The monomers can have acrylic, vinyl, maleic, fumaric, allylic functionalities and contain in an carboxy group, phosphonate, sulfonate, or another group with an anionic charge, or the ammonium or alkaline earth metal or corresponding alkali metal salt. of such a monomer.

Examples of suitable monomers include acrylic acid, methacryiic acid, acryiamidomethypropane sulfonic acid, acrylamidomethylbutanoic acid, maleic acid, fumaric acid, itaconic acid, vinyisulfonic acid, styrene acid sulfonic, vinylphosphonic acid, allylsulfonic acid, allylphosphonic acid and their water-soluble salts of an alkali metal, an alkaline earth metal, and ammonium. Cationic monomers'

As cationic monomers, those corresponding to the following formula may be used:

CH2 == C - R1 R2

0 = C - A1— B 1— N _ R4 ^{x "}

I ^R3

in which R represents H or CH ₃ ; R ₂ and R ₃ represent C 1 -C 8 alkyl groups; R ₄ represents H or a C 1 -C ₄ alkyl group or an (alkyi) aryl group or a substituted aryl group; A _t represents an oxygen or NH atom; B ₁ represents an alkylene group in

or a hydroxypropylene group, and X ^~ is an anionic counter ion.

Cationic monomers such as derivatives of diallyldialkylammonium halides can also be used.

7 A method according to any one of claims 1 to 6 characterized in that one can use any organic or inorganic salt allowing the insolubilization of the prepared polymer can be used according to the invention. Preferred salts are those comprising the sulfate, dihydrogen phosphate, phosphate and halide anions. The corresponding cations can be sodium, potassium, ammonium, magnesium, aluminum. The simultaneous use of two or more of these salts is also possible.

8 A method according to any one of claims 1 to 7, wherein the dispersant is a polymeric electrolyte and or a polyol and / or a derivative of caώone hydrates soluble in an aqueous saline solution; the preferred dispersing polymers being:

For dispersions of anionically charged polymers: the particularly preferred dispersing polymers are homopolymers and copolymers obtained from 2-acrylamido-2-methyl-1-propane sulfonic acid or its salts or acid

(meth) acrylic or its salts and the copolymers obtained from these monomers and from the aforementioned nonionic monomers. For dispersions of polymers with a cationic charge: the particularly preferred dispersing polymers are polyamines, such as for example polymers resulting from the condensation of epichlorohydrin and dimethylamine, homopolymers and copolymers obtained from one or more monomers ( s) cationic; as cationic monomers, mention may be made, for example, of quaternized derivatives of N, N-dimethylamino ethyl (meth) acrylate, N, N-dimethylamino propyl (meth) acrylate, N, N-dimethylamino propyl (meth) acrylamide or N, N-dimethylamino hydroxypropyl (meth) acrylate or diallyldialkylammonium halides, and the copolymers obtained from these monomers and from the aforementioned nonionic monomers.

Particularly preferred dispersing polymers, being polyalkylene ethers, for example polyethylene glycol, polypropylene glycol or the homopolymer of 2-acrylamido-2-methyl-1-propane sulfonic acid, polydiallyldimethylammonium chloride (poly-DADMAC) and / or polyacryloyloxyethyltrimethyl ammonium chloride and their derivatives.

9 A method according to any one of claims 1 to 8, wherein the dispersant is a single dispersant or a mixture of dispersants.

10 Polymers and copolymers characterized in that they are obtained by a process according to any one of claims 1 to 9.

11 Nonionic, anionic, cationic or amphoteric polymers and copolymers according to claim 10, both linear and slightly or strongly branched, or crosslinked (by an effective proportion of crosslinking agent).

12 Application in the polymer and copolymer industry according to claim 10 or 11 and methods according to any one of claims 1 to 9, in particular the paper industry, water treatment (drinkable or used), in general all coagulation / flocculation techniques, the mining industry, the petroleum and refining industry, the cosmetics industry, the textile industry, and all similar applications which will be obvious to those skilled in the art.