CA1247292A - Water treatment polymers and methods of use thereof - Google Patents
Water treatment polymers and methods of use thereofInfo
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- CA1247292A CA1247292A CA000525311A CA525311A CA1247292A CA 1247292 A CA1247292 A CA 1247292A CA 000525311 A CA000525311 A CA 000525311A CA 525311 A CA525311 A CA 525311A CA 1247292 A CA1247292 A CA 1247292A
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Abstract
ABSTRACT OF THE DISCLOSURE
Scale control polymers and methods of use are disclosed.
The polymers are water soluble and are composed of repeat units formed from an .alpha.,.beta. ethylenically unsaturated compound, and repeat units formed from allyl alkylene phosphite ethers.
Scale control polymers and methods of use are disclosed.
The polymers are water soluble and are composed of repeat units formed from an .alpha.,.beta. ethylenically unsaturated compound, and repeat units formed from allyl alkylene phosphite ethers.
Description
~7;~9~
WATER T~EATMENT POLYMERS AND METHODS OF USE THEREOF
Field of the Invention The present i mention pertains to a composition and method of utili~ing same to control the formation and deposition of sc~le impartins compounds in water systems such as cooling, boiler - and gas scrubbing systems.
Background of the Invention The problew of scale formation and attendant effects have troubled water systems for years. For instance, scale tends to accumulate on internal walls of various water systems, such as boiler and cooling systems3 and thereby materially lessens the operational efficiency oF the system.
Deposits in lines, heat exchange equipment, etc., may originate frow several causes. For example, precipitation of calcium carbonate~ calcium sulfate and calcium phosphate in the r, 3 ~æ
:~2~729~
water system leads to an accumulation of these scale imparting compounds along or around the metal surfaces which contact the flowing wa~er circulating through the system. In this manner, heat transfer functions of the particular system are severely impeded.
Typically, in cooling water systems, the formation of calcium sulfate, calcium phosphate and calcium carbonate, among others, has proYen deleterious to the overall efficiency of the cooling water system. Recently9 due to the popularity of cooling treatments using high levels of orthophosphate to promote passivation of the metal surfaces in contact with the system water, it has become critically important to control calcium phosphate crystallization so that relatively high levels of orthophosphate may be maintained in the system to achieve the desired passivation withou~ resulting in fouling or impeded heat transfer functions 1~ which would normally be caused by calc;um phosphate deposition.
Although steam generating systems are somewhat different from cooling water systems, they share a common problem in règard to deposit formation.
, As detailed in the Bet Handbook of Industrial ~ater ?0 Conditioning, 8th Edition~ lg80, Betz Laboratories, Inc., Trevose, PA Pages 85-96, the formation of scale and sludge deposits on boiler hea~inq surfaces is a serious problem encountered in steam genera-tion. Although current industrial steam producing systems make use of sophisticated external trea~ments of the boiler feedwater, e.g.,
WATER T~EATMENT POLYMERS AND METHODS OF USE THEREOF
Field of the Invention The present i mention pertains to a composition and method of utili~ing same to control the formation and deposition of sc~le impartins compounds in water systems such as cooling, boiler - and gas scrubbing systems.
Background of the Invention The problew of scale formation and attendant effects have troubled water systems for years. For instance, scale tends to accumulate on internal walls of various water systems, such as boiler and cooling systems3 and thereby materially lessens the operational efficiency oF the system.
Deposits in lines, heat exchange equipment, etc., may originate frow several causes. For example, precipitation of calcium carbonate~ calcium sulfate and calcium phosphate in the r, 3 ~æ
:~2~729~
water system leads to an accumulation of these scale imparting compounds along or around the metal surfaces which contact the flowing wa~er circulating through the system. In this manner, heat transfer functions of the particular system are severely impeded.
Typically, in cooling water systems, the formation of calcium sulfate, calcium phosphate and calcium carbonate, among others, has proYen deleterious to the overall efficiency of the cooling water system. Recently9 due to the popularity of cooling treatments using high levels of orthophosphate to promote passivation of the metal surfaces in contact with the system water, it has become critically important to control calcium phosphate crystallization so that relatively high levels of orthophosphate may be maintained in the system to achieve the desired passivation withou~ resulting in fouling or impeded heat transfer functions 1~ which would normally be caused by calc;um phosphate deposition.
Although steam generating systems are somewhat different from cooling water systems, they share a common problem in règard to deposit formation.
, As detailed in the Bet Handbook of Industrial ~ater ?0 Conditioning, 8th Edition~ lg80, Betz Laboratories, Inc., Trevose, PA Pages 85-96, the formation of scale and sludge deposits on boiler hea~inq surfaces is a serious problem encountered in steam genera-tion. Although current industrial steam producing systems make use of sophisticated external trea~ments of the boiler feedwater, e.g.,
2~ ooagula~ion, filtration, softening of water prior to its feed into the ~oiler s~stem, these o~erations are only moderately effective.
In all cases, external treatment does not in itself provide adequate treatment since muds, sludgeZ silts and hardness-imparting ions 9;~
escape the treatment, and eventually are introduced into the steam generating system.
In addition to the problems caused by mud, sludge or silts, the industry has also had to contend with boiler scale.
Although external treatment is utilized specifically in an attempt to remove calcium and magnesium from the feedwater, scale formation due to residual hardness, i.e., calcium and magnesium salts, is always experienced. Accordingly, internal treatment, i.e., treatment of the water fed to the system, is necessary to prevent, reduce and/or retard formation of the scale imparting compounds and their resultant deposition. The carbonates of magnesium and calcium are not the only problem compounds as regards scale, but also waters having high contents of phosphate, sulfate and silicate ions either occurring naturally or added for other purposes cause problems since l~ calcium and magnesium, and any iron or copper present, react with each and deposit as boiler scale. As is obvious, deposition on the structural parts of a steam generating system causes poorer circulation and lower heat transfer capacity, resulting in an oYerall loss in efficiency.
2~ Summ~ry of the Invention ~ e have found that certain allyl alkylene phosphite ether copolymers and terpolymers function to contrsl the formation of mineral deposits in water systems. Specifically, the novel copo1ymers of the invention have the structure ~2~Z~
--CE~-- --{C~l2_ CH~
o FORMULA I
IR
H P OM
o wherein E in the above formula is the residue remaining after polymeri~ation of an ~,B ethylenically unsaturated compound, preferably carboxylic acid, amide form thereof, or lower alkyl (C
- C6) ester or hydroxylated lower alkyl (C~ - C6) ester of such carboxylic acid. Compounds encompassed by E include the residue remaining after polymerization of acrylic acid, methacrylic acid, acrylamide, maleic acid or anhydride, styrene, and itaconic acid, and the like. ~ater soluble salt forms of the carboxylic acids are also within the purview of the invention.
One or more differently structured monomers may be used as the E constituent provided that they fall within the definition of E above given. One such preferred mixture of E monomers would be acrylic acid/2-hydroxypropyl acrylate.
Rl in the above formula (Formula I) is a hydroxy substituted lower alkylen~ group having from about l to 6 carbon atoms or a non-substituted lower alkylene group having from 1 to 6 carbon atoms. M in Formula I is a water soluble cation (e.g., ~H4 , alkali metal) or hydrogen.
~Z ~29~
PRIOR ART
U.S. Patent 4,~00,693 (Takehara9 et. al.) discloses sundry copolymers composed of a (meth) acrylic acid monomer and an allylic ether monomer. Such polymers are disclosed as being useful dispersants and scale preventing agents that may be used in cooling water or water collection systems, etc. One of the Japanese priority applications corresponding to the '693 U.S. Patent indicates that the invention is directed toward a low or non-phosphorus scale control treatment approach.
In accordance with the '693 disclosure, the allylic e~her monomer may include, inter alia, the reaction product of allyloxy dihydroxypropane with various reagents, such as, ethylene oxide, phosphorus pentoxide, propylene oxide, monoaryl sorbitan, etc. When phosphorus pentoxide is reacted with allyloxydihydroxypropane, the resulting product is reported to contain phosphate functionality --in contrast to the phosphite functionality bonded to the polymer matrix in accordance with the present invention.
- Further, in a comparative test, a polymer of the present invention, namely an acrylic acid/gly~eryl allyl ether/allyloxy-?O hy~roxypropyl phosphite terpolymer exhibited surprising andunexpectedly superior results9 in comparison to a phosphate con~aining polymer prepared in accordance wi~h Example 2 of the '693 patent disclosure.
As stated above, control of calcium phosphate has become critical to those ~ater systems that maintain relatively high or~hophosphate levels so as to aid in the formation of highly desirable passive oxide film along water system metallurgy. For example, Godlewski, et. al., U.S. Patent 4,029,577 teaches that certain acrylic acid type/hydroxyalkyl (meth) acrylates are effectiYe calcium phosphate scale control a~ents. In U.S. Patent 4,303,568 (May, et. al.) methods of utilizing such polymers to form 5 passivated films are taught.
Of further interest to the present invention is U.S.
Patent 4,207,405 (Masler, et. al.) wherein water treatment usage of certain phosphorous acid/carboxylic polymer reaction products is taught. Specific teachings of this reference include reaction of 10 poly (meth) acrylic acid with phosphorous acid or precursor thereof to yield a hydroxydiphosphonic acid adduct with the polymer. The disclosed reaction must be carried out under anhydrous conditions, with the product then being hydrolyzed in an aqueous medium. The precise structure of the reaction product is difficult to identify 15 and contains only low levels of phosphorus substitution.
Of lesser interest are U.S. Patents 3,262,903 (Robertson) and 2,723,971 (Cupery~ which teach reaction of a polyepoxide with orthophosphoric acid to provide a polymer having a phosphoric acid ester substituent. The resulting polymeric phosphate is soluble in 2~ organic solvents and is useful as a film forming ingredient in coatin~ compos;tions. It cannot be used in the water treatment field wherein water solubility is an essential criterion.
Other prior art patents and publications which may be of interest include: Japanese Patent 56-155692, U.S. Patent 4,209,398 t~i~ et. al.) and U.S. Patent 4,469,615 tTsuruoka~ et. al.).
L7~9 Detailed Description of the Invention In accordance with the invention, it has been discovered that water soluble copolymers and terpolymers, as shown in Formula I
hereinafter, are effective in controlling the formation of mineral deposits and in inhibiting corrosion in various water systems.
These polymers comprise monomeric repeat units composed of an ethylenically unsaturated compound or compounds and allyl alkylene phosphite ether compounds, wherein the alkylene group comprises from about 1 - 6 carbon atoms.
The water soluble copolymers and terpolymers of the invention have the structure:
FORMULA I
~ E ~ ~ CH2 - CH
,. 1CH2 R
o H - P - GM
O
wherein E in the aboYe formula is the residue remaining after polymerization of an ~,~ ethylenically unsaturated compound, preferably carboxylic acid, amide fsrm thereof, or lower alkyl (Cl ~ C6) ester or hydroxylated lower alkyl ~Cl - C6) ester of such car~oxylic acid. Compounds encompassed by E include the ~l2~72~
residue remaining after polymerization of acrylic acid, methacrylic acid, acrylamide, maleic acid or anhydride, styrene and itaconic acid; and the like. Water soluble salt forms of the carboxylic acids are also within the purview of the invention.
One or more differently structured monomers may be used as the E constituent provided that they fall within the definition of E above given. One such preferred mixture of E monomers would be acrylic acid/2-hydroxypropyl acrylate.
Rl in the above formula ~Formula I) is a hydroxy - 10 substituted lower alkylene group having from about 1 to 6 carbon atoms or a non-substituted lower alkylene group having from 1 to 6 carbon atoms. M in Formula I is a water soluble cation (e.g., NH4 , alkali metal) or hydrogen.
The molar ratio of the monomers (g:h) of Formula I may - 15 fall within the range of 30:1 to l:20, with a molar ratio (g:h) of about 10:1 to 1:5 being preferred.
- The number a~erage molecular weight of the water soluble copolymers of Formula I may fall within the range of 1, 000 to 1,000,000. Preferably, the number average molecular weight will be within the range of about 1,500 to about 500,000, with the range of about 1,500 to about 10,000 being eYen more highly desirable. The key criterion is ~hat the polymer be water soluble.
As to preparation of the monomer designated as g herein-abo~e, these may be in accordance with well known techniques. For instance, one such possible monomer, acrylic acid, may be prepared by hydrolysis of acrylonitrile or by oxidation of acrolein.
7~
As to the allyl ether monomer (monomer h), this may be prepared in accordance with the disclosure of U.S. Patent 2,847,477 followed by reaction with H3P03 (which is hereby incorporated herein by reference) or it may, more preferably, be prepared by a ring opening reaction using an allyl glycidyl ether ~AGE~ precursor to prepare the preferred l-allyloxy hydroxypropyl phosphite monomer. To prepare the other acceptable l-allyloxy hydroxyalkyl (Cl - C6) phosphite monomers, the skilled artisan will simply utilize the corresponding epoxide.
The AGE is reacted with phosphorous acid (H3P03) or precursor, such as PC13, to form a mixed monomer solution in accordance with the equation:
CH2 = CH - CH2 -- O - CH2 - CH -~CH2 ~ H3P03 NaOH
H
CH2 = CH - CH2 - O - CH2 - CH(OH) - CH2 - O - P = O
O Na (AHPP~ allyloxy hydroxy propane phosphite primary isomer (major) CH2 = CH - CH2 - O - CH2 - CH - O - P = O
CH20H O Na A~PP secondary isomer (minor) ~Z~72g'~
- 10 _ CH2 = CH - CH2 - O - CH2 - CH (OH) - CH20H
l-allyloxy-2,3-dihydroxypr~pane (hydrolysate--hydrolys;s product--of AGE--glyceryl allyl ether--GAE--) The reaction may be carried out in an aqueous medium with a reaction temperature ranging from 25 to 99C. For each mole of phosphorous acid used, 1.0 to 2.0 moles of sodium hydroxide may be used, with 1.0 to 1.5 moles being preferred. Allyl glycidyl e~her may be added over a period of from half an hour to four hours with the longer time being preferred.
The structures of the preferred allyloxy hydroxypropyl phosphites (AHPP) were substantiated by 13C and 31p NMR
spectroscopy and IR spectra. The 31p NMR spectra showed two major resonances at 8.7 ppm and 7.3 ppm downfield from external phosphoric acid. These were assigned to the primary and secondary monosodium allyloxy hydroxy propyl phosphites (AHPP), respectively. The one-bond P-H coupling constant is approximately 620 Hz. A trace of inorganic phosphite was noted at 4.3 ppm. The 13C NMR showed the A~PP at 64.5, 68.9, 70.3, 71.8, 113.1 and 133.8 ppm downfield from external dioxane. The IR spectra showed an intense P-H stretch at 2380 cm 1 and P=O stre~ch at 12.10 cm 1, The glyceryl allyl ether ~GAE) was detected by 13C NMR at 63.2, 70.4, 70.8 and 7106 ppm.
It is noted that the Na ion present in the AHPP monomer 26 above may be replaced with hydrogen, K, NH~ , or any water soluble cation. The Na ion may also be replaced by an organic amine i~7~
"
group or lower alkyl group of from about 1-3 carbon atoms. The molar ratio of the AGE:AHPP components in the mixed monomer solution may be varied to result in different ratios of these two components in the resulting polymer.
C'. ~ l~ 3~ 3, In ~ o~Ei~ r6r~t~e it was originally thought that reaction of AGE with H3P03 would yield a phosphonate reaction product. However, NMR analysis has now revealed that a phosphite functionality is actually formed.
If desired, the l-allyloxy-2,3-dihydroxypropane (GAE
hydrolysate of AGE) may be removed from the mixed monomer solution ~i.e., leaving an aqueous solution of the two AHPP monomers) via distillation, solvent extraction, etc. At present, it is preferred to utilize the mixed monomer solution as it is produced (which there~ore includes l-allyloxy-2,3-dihydroxypropane GAE). In such cases, after polymerization, the resulting polymer comprises l~allyloxy-2,3-dihydroxy propane (GAE) which incorporates into the polymeric matrix along with the AHPP isomers. ~hen the GAE
component of the mixed monomer solution is not removed, the resulting terpolymer may comprise:
mole %
c~,~ ethylenically unsaturated monomer 40 - 90 with the foregoing adding up to lOU mole~.
~7~g;~
After the desired monomers are produced and isolated, radical polymerization may proceed in solution, suspension, bulk, emulsion or thermal polymeri~ation form. For instance, in suspension polymerization, the reaction may be initiated by an a20 compound or an organic peroxide, with the monomers suspended in hexane or other organic reagents. On the other hand, in solution polymerization, the reaction may be initiated via conventional persulfate or peroxide initiators. Commonly used chain transfer agents such as lower alkyl alcohols, amines or mercapto compounds may be used to regulate ~he molecular weight~ An accelerator such as sodium bisulfite or ascorbic acid may also be used.
The fact that polymers were formed by the above method was substantiated by viscosity increase, gel permeation chromato-graphy, IR, 13C and 31p NMR spectroscopy. The 13C NMR spectra 1~ showed a broad, polymer type backbone with complex C-O region ~62-74 ppm~ and no evidence of unreacted monomers. The 31p NMR spectra were similar to that of allyloxy hydroxypropyl phosphite but with broader absorption, an indication of polymer formation.
Since, in accordance with the preferred method for obtaining the phosphite monomer, minor amounts of 1-allyloxy-2,3-dihydroxypropane will incorporate into the polymeric matrix when the preferred synthetic route~ including use of the mixed monomer solution is used, the resulting structure of the polymer is ~729~
FORMULA II
{ E ~ 9 ~ 2 1 ~ h tCH2 IH
CH2 1~12 O O
Il R2 o H - P - OM
o wherein g and h are the same as in Formula I. R2 is a hydroxyl-ated lower alkyl (Cl - C6) grouping. Monomer (i) may be present in a molar amount of between about 1 - 35%, with monomer 9 being present in a molar amount of between about 40 - 90%. Monomer h is present in an amount of about 2 - 40%. All of the foregoing molar percentages should add up to 100~.
The specific preferred polymer is a terpolymer of the sodium salt of acrylic acid/allyl hydroxy propyl phosphite ether/l-allyloxy-2,3-dihydroxypropane ~presen~ in only a minor amount~
haYing the structure:
`~2~7 FORMULA III
_ [CH2 - IH } - ~CH2 IH ~ h { CH2- CH
C = O lH2 lH2 O Na l I
fH2 fH2 fHOH fHOH
CoH2 CH20H
- H - P - O Na o The polymers should be added to the aqueous system, for which deposit control activity is desired, in an amount effective for the purpose. This amount will vary depending upon the particular system for which treatment is desired and will be influenced by factors such as~ the area subJect to deposition, pH, temperature, water quantity and the respeckive concentrations in the water of the potential scale and deposit forming species. For the most part, the polymers will be effective when used at levels of about 0.1-500 parts per million parts of water, and preferably from about 1.0 to 100 parts per million of water contained in the aqueous system to be treated. The polymers may be added directly into the desired water system in a fixed quantity and in the state of an
In all cases, external treatment does not in itself provide adequate treatment since muds, sludgeZ silts and hardness-imparting ions 9;~
escape the treatment, and eventually are introduced into the steam generating system.
In addition to the problems caused by mud, sludge or silts, the industry has also had to contend with boiler scale.
Although external treatment is utilized specifically in an attempt to remove calcium and magnesium from the feedwater, scale formation due to residual hardness, i.e., calcium and magnesium salts, is always experienced. Accordingly, internal treatment, i.e., treatment of the water fed to the system, is necessary to prevent, reduce and/or retard formation of the scale imparting compounds and their resultant deposition. The carbonates of magnesium and calcium are not the only problem compounds as regards scale, but also waters having high contents of phosphate, sulfate and silicate ions either occurring naturally or added for other purposes cause problems since l~ calcium and magnesium, and any iron or copper present, react with each and deposit as boiler scale. As is obvious, deposition on the structural parts of a steam generating system causes poorer circulation and lower heat transfer capacity, resulting in an oYerall loss in efficiency.
2~ Summ~ry of the Invention ~ e have found that certain allyl alkylene phosphite ether copolymers and terpolymers function to contrsl the formation of mineral deposits in water systems. Specifically, the novel copo1ymers of the invention have the structure ~2~Z~
--CE~-- --{C~l2_ CH~
o FORMULA I
IR
H P OM
o wherein E in the above formula is the residue remaining after polymeri~ation of an ~,B ethylenically unsaturated compound, preferably carboxylic acid, amide form thereof, or lower alkyl (C
- C6) ester or hydroxylated lower alkyl (C~ - C6) ester of such carboxylic acid. Compounds encompassed by E include the residue remaining after polymerization of acrylic acid, methacrylic acid, acrylamide, maleic acid or anhydride, styrene, and itaconic acid, and the like. ~ater soluble salt forms of the carboxylic acids are also within the purview of the invention.
One or more differently structured monomers may be used as the E constituent provided that they fall within the definition of E above given. One such preferred mixture of E monomers would be acrylic acid/2-hydroxypropyl acrylate.
Rl in the above formula (Formula I) is a hydroxy substituted lower alkylen~ group having from about l to 6 carbon atoms or a non-substituted lower alkylene group having from 1 to 6 carbon atoms. M in Formula I is a water soluble cation (e.g., ~H4 , alkali metal) or hydrogen.
~Z ~29~
PRIOR ART
U.S. Patent 4,~00,693 (Takehara9 et. al.) discloses sundry copolymers composed of a (meth) acrylic acid monomer and an allylic ether monomer. Such polymers are disclosed as being useful dispersants and scale preventing agents that may be used in cooling water or water collection systems, etc. One of the Japanese priority applications corresponding to the '693 U.S. Patent indicates that the invention is directed toward a low or non-phosphorus scale control treatment approach.
In accordance with the '693 disclosure, the allylic e~her monomer may include, inter alia, the reaction product of allyloxy dihydroxypropane with various reagents, such as, ethylene oxide, phosphorus pentoxide, propylene oxide, monoaryl sorbitan, etc. When phosphorus pentoxide is reacted with allyloxydihydroxypropane, the resulting product is reported to contain phosphate functionality --in contrast to the phosphite functionality bonded to the polymer matrix in accordance with the present invention.
- Further, in a comparative test, a polymer of the present invention, namely an acrylic acid/gly~eryl allyl ether/allyloxy-?O hy~roxypropyl phosphite terpolymer exhibited surprising andunexpectedly superior results9 in comparison to a phosphate con~aining polymer prepared in accordance wi~h Example 2 of the '693 patent disclosure.
As stated above, control of calcium phosphate has become critical to those ~ater systems that maintain relatively high or~hophosphate levels so as to aid in the formation of highly desirable passive oxide film along water system metallurgy. For example, Godlewski, et. al., U.S. Patent 4,029,577 teaches that certain acrylic acid type/hydroxyalkyl (meth) acrylates are effectiYe calcium phosphate scale control a~ents. In U.S. Patent 4,303,568 (May, et. al.) methods of utilizing such polymers to form 5 passivated films are taught.
Of further interest to the present invention is U.S.
Patent 4,207,405 (Masler, et. al.) wherein water treatment usage of certain phosphorous acid/carboxylic polymer reaction products is taught. Specific teachings of this reference include reaction of 10 poly (meth) acrylic acid with phosphorous acid or precursor thereof to yield a hydroxydiphosphonic acid adduct with the polymer. The disclosed reaction must be carried out under anhydrous conditions, with the product then being hydrolyzed in an aqueous medium. The precise structure of the reaction product is difficult to identify 15 and contains only low levels of phosphorus substitution.
Of lesser interest are U.S. Patents 3,262,903 (Robertson) and 2,723,971 (Cupery~ which teach reaction of a polyepoxide with orthophosphoric acid to provide a polymer having a phosphoric acid ester substituent. The resulting polymeric phosphate is soluble in 2~ organic solvents and is useful as a film forming ingredient in coatin~ compos;tions. It cannot be used in the water treatment field wherein water solubility is an essential criterion.
Other prior art patents and publications which may be of interest include: Japanese Patent 56-155692, U.S. Patent 4,209,398 t~i~ et. al.) and U.S. Patent 4,469,615 tTsuruoka~ et. al.).
L7~9 Detailed Description of the Invention In accordance with the invention, it has been discovered that water soluble copolymers and terpolymers, as shown in Formula I
hereinafter, are effective in controlling the formation of mineral deposits and in inhibiting corrosion in various water systems.
These polymers comprise monomeric repeat units composed of an ethylenically unsaturated compound or compounds and allyl alkylene phosphite ether compounds, wherein the alkylene group comprises from about 1 - 6 carbon atoms.
The water soluble copolymers and terpolymers of the invention have the structure:
FORMULA I
~ E ~ ~ CH2 - CH
,. 1CH2 R
o H - P - GM
O
wherein E in the aboYe formula is the residue remaining after polymerization of an ~,~ ethylenically unsaturated compound, preferably carboxylic acid, amide fsrm thereof, or lower alkyl (Cl ~ C6) ester or hydroxylated lower alkyl ~Cl - C6) ester of such car~oxylic acid. Compounds encompassed by E include the ~l2~72~
residue remaining after polymerization of acrylic acid, methacrylic acid, acrylamide, maleic acid or anhydride, styrene and itaconic acid; and the like. Water soluble salt forms of the carboxylic acids are also within the purview of the invention.
One or more differently structured monomers may be used as the E constituent provided that they fall within the definition of E above given. One such preferred mixture of E monomers would be acrylic acid/2-hydroxypropyl acrylate.
Rl in the above formula ~Formula I) is a hydroxy - 10 substituted lower alkylene group having from about 1 to 6 carbon atoms or a non-substituted lower alkylene group having from 1 to 6 carbon atoms. M in Formula I is a water soluble cation (e.g., NH4 , alkali metal) or hydrogen.
The molar ratio of the monomers (g:h) of Formula I may - 15 fall within the range of 30:1 to l:20, with a molar ratio (g:h) of about 10:1 to 1:5 being preferred.
- The number a~erage molecular weight of the water soluble copolymers of Formula I may fall within the range of 1, 000 to 1,000,000. Preferably, the number average molecular weight will be within the range of about 1,500 to about 500,000, with the range of about 1,500 to about 10,000 being eYen more highly desirable. The key criterion is ~hat the polymer be water soluble.
As to preparation of the monomer designated as g herein-abo~e, these may be in accordance with well known techniques. For instance, one such possible monomer, acrylic acid, may be prepared by hydrolysis of acrylonitrile or by oxidation of acrolein.
7~
As to the allyl ether monomer (monomer h), this may be prepared in accordance with the disclosure of U.S. Patent 2,847,477 followed by reaction with H3P03 (which is hereby incorporated herein by reference) or it may, more preferably, be prepared by a ring opening reaction using an allyl glycidyl ether ~AGE~ precursor to prepare the preferred l-allyloxy hydroxypropyl phosphite monomer. To prepare the other acceptable l-allyloxy hydroxyalkyl (Cl - C6) phosphite monomers, the skilled artisan will simply utilize the corresponding epoxide.
The AGE is reacted with phosphorous acid (H3P03) or precursor, such as PC13, to form a mixed monomer solution in accordance with the equation:
CH2 = CH - CH2 -- O - CH2 - CH -~CH2 ~ H3P03 NaOH
H
CH2 = CH - CH2 - O - CH2 - CH(OH) - CH2 - O - P = O
O Na (AHPP~ allyloxy hydroxy propane phosphite primary isomer (major) CH2 = CH - CH2 - O - CH2 - CH - O - P = O
CH20H O Na A~PP secondary isomer (minor) ~Z~72g'~
- 10 _ CH2 = CH - CH2 - O - CH2 - CH (OH) - CH20H
l-allyloxy-2,3-dihydroxypr~pane (hydrolysate--hydrolys;s product--of AGE--glyceryl allyl ether--GAE--) The reaction may be carried out in an aqueous medium with a reaction temperature ranging from 25 to 99C. For each mole of phosphorous acid used, 1.0 to 2.0 moles of sodium hydroxide may be used, with 1.0 to 1.5 moles being preferred. Allyl glycidyl e~her may be added over a period of from half an hour to four hours with the longer time being preferred.
The structures of the preferred allyloxy hydroxypropyl phosphites (AHPP) were substantiated by 13C and 31p NMR
spectroscopy and IR spectra. The 31p NMR spectra showed two major resonances at 8.7 ppm and 7.3 ppm downfield from external phosphoric acid. These were assigned to the primary and secondary monosodium allyloxy hydroxy propyl phosphites (AHPP), respectively. The one-bond P-H coupling constant is approximately 620 Hz. A trace of inorganic phosphite was noted at 4.3 ppm. The 13C NMR showed the A~PP at 64.5, 68.9, 70.3, 71.8, 113.1 and 133.8 ppm downfield from external dioxane. The IR spectra showed an intense P-H stretch at 2380 cm 1 and P=O stre~ch at 12.10 cm 1, The glyceryl allyl ether ~GAE) was detected by 13C NMR at 63.2, 70.4, 70.8 and 7106 ppm.
It is noted that the Na ion present in the AHPP monomer 26 above may be replaced with hydrogen, K, NH~ , or any water soluble cation. The Na ion may also be replaced by an organic amine i~7~
"
group or lower alkyl group of from about 1-3 carbon atoms. The molar ratio of the AGE:AHPP components in the mixed monomer solution may be varied to result in different ratios of these two components in the resulting polymer.
C'. ~ l~ 3~ 3, In ~ o~Ei~ r6r~t~e it was originally thought that reaction of AGE with H3P03 would yield a phosphonate reaction product. However, NMR analysis has now revealed that a phosphite functionality is actually formed.
If desired, the l-allyloxy-2,3-dihydroxypropane (GAE
hydrolysate of AGE) may be removed from the mixed monomer solution ~i.e., leaving an aqueous solution of the two AHPP monomers) via distillation, solvent extraction, etc. At present, it is preferred to utilize the mixed monomer solution as it is produced (which there~ore includes l-allyloxy-2,3-dihydroxypropane GAE). In such cases, after polymerization, the resulting polymer comprises l~allyloxy-2,3-dihydroxy propane (GAE) which incorporates into the polymeric matrix along with the AHPP isomers. ~hen the GAE
component of the mixed monomer solution is not removed, the resulting terpolymer may comprise:
mole %
c~,~ ethylenically unsaturated monomer 40 - 90 with the foregoing adding up to lOU mole~.
~7~g;~
After the desired monomers are produced and isolated, radical polymerization may proceed in solution, suspension, bulk, emulsion or thermal polymeri~ation form. For instance, in suspension polymerization, the reaction may be initiated by an a20 compound or an organic peroxide, with the monomers suspended in hexane or other organic reagents. On the other hand, in solution polymerization, the reaction may be initiated via conventional persulfate or peroxide initiators. Commonly used chain transfer agents such as lower alkyl alcohols, amines or mercapto compounds may be used to regulate ~he molecular weight~ An accelerator such as sodium bisulfite or ascorbic acid may also be used.
The fact that polymers were formed by the above method was substantiated by viscosity increase, gel permeation chromato-graphy, IR, 13C and 31p NMR spectroscopy. The 13C NMR spectra 1~ showed a broad, polymer type backbone with complex C-O region ~62-74 ppm~ and no evidence of unreacted monomers. The 31p NMR spectra were similar to that of allyloxy hydroxypropyl phosphite but with broader absorption, an indication of polymer formation.
Since, in accordance with the preferred method for obtaining the phosphite monomer, minor amounts of 1-allyloxy-2,3-dihydroxypropane will incorporate into the polymeric matrix when the preferred synthetic route~ including use of the mixed monomer solution is used, the resulting structure of the polymer is ~729~
FORMULA II
{ E ~ 9 ~ 2 1 ~ h tCH2 IH
CH2 1~12 O O
Il R2 o H - P - OM
o wherein g and h are the same as in Formula I. R2 is a hydroxyl-ated lower alkyl (Cl - C6) grouping. Monomer (i) may be present in a molar amount of between about 1 - 35%, with monomer 9 being present in a molar amount of between about 40 - 90%. Monomer h is present in an amount of about 2 - 40%. All of the foregoing molar percentages should add up to 100~.
The specific preferred polymer is a terpolymer of the sodium salt of acrylic acid/allyl hydroxy propyl phosphite ether/l-allyloxy-2,3-dihydroxypropane ~presen~ in only a minor amount~
haYing the structure:
`~2~7 FORMULA III
_ [CH2 - IH } - ~CH2 IH ~ h { CH2- CH
C = O lH2 lH2 O Na l I
fH2 fH2 fHOH fHOH
CoH2 CH20H
- H - P - O Na o The polymers should be added to the aqueous system, for which deposit control activity is desired, in an amount effective for the purpose. This amount will vary depending upon the particular system for which treatment is desired and will be influenced by factors such as~ the area subJect to deposition, pH, temperature, water quantity and the respeckive concentrations in the water of the potential scale and deposit forming species. For the most part, the polymers will be effective when used at levels of about 0.1-500 parts per million parts of water, and preferably from about 1.0 to 100 parts per million of water contained in the aqueous system to be treated. The polymers may be added directly into the desired water system in a fixed quantity and in the state of an
3~ aqueo~s solution, con~inuously or intermittently.
The polymers of the present invention are not limited to use in any speoific cate~ory of water system. For instance, in addition to boiler and covling water systems, the polymers may also ` ~2~2 be effectively utilized in scrubber systems and the like wherein the formation and deposition of scale forming salts is a problem. Other possible environments in wh;ch the inventive polymers may be used include heat distribution type sea water desalting apparatus and dust collection systems in iron and steel manufacturing industries and as a dispersant in the pulp and paper processing industries.
Also the polymers could be used as mineral beneficiation aids such as in iron ore, phosphate, ancl potash recovery.
Examples 1~ The inYention will now be further described with reference to a nu~ber of specific examples which are to be regarded solely as illustrative, and not as restricting the scope of the invention.
Example 1 - Preparation of 1-propane phosphite, 2-hydroxy-3-(2-propenyloxy)-monosodium salt, ~Monosodium ~ y-loxyhydroxypropyl Phosphite) and GAE mixed monomer sol Uti on A suitable reaction flask was equipped with a reflux condenser, an addition funnel, an ov~rhead stirrer, a thermometer and a nitrogen inlet. 1609 of 50% sodium hydroxide (2 mol) and 1239 of deionized water were charged to the flask. 1649 of phosphorous acid (2 mol) were then slowly added to the caustic solution under a nitrogen blanket. The reac~ion was maintained below 50C. After this addition, the resulting solution was heated to 95-99C. 228g of allyl glycidyl ether (AGE, 2 mol) were added to the flask in 3 hours. After this addition, the mixture was stirred for an additional 15 minutes at 99C and then the volatiles were removed at
The polymers of the present invention are not limited to use in any speoific cate~ory of water system. For instance, in addition to boiler and covling water systems, the polymers may also ` ~2~2 be effectively utilized in scrubber systems and the like wherein the formation and deposition of scale forming salts is a problem. Other possible environments in wh;ch the inventive polymers may be used include heat distribution type sea water desalting apparatus and dust collection systems in iron and steel manufacturing industries and as a dispersant in the pulp and paper processing industries.
Also the polymers could be used as mineral beneficiation aids such as in iron ore, phosphate, ancl potash recovery.
Examples 1~ The inYention will now be further described with reference to a nu~ber of specific examples which are to be regarded solely as illustrative, and not as restricting the scope of the invention.
Example 1 - Preparation of 1-propane phosphite, 2-hydroxy-3-(2-propenyloxy)-monosodium salt, ~Monosodium ~ y-loxyhydroxypropyl Phosphite) and GAE mixed monomer sol Uti on A suitable reaction flask was equipped with a reflux condenser, an addition funnel, an ov~rhead stirrer, a thermometer and a nitrogen inlet. 1609 of 50% sodium hydroxide (2 mol) and 1239 of deionized water were charged to the flask. 1649 of phosphorous acid (2 mol) were then slowly added to the caustic solution under a nitrogen blanket. The reac~ion was maintained below 50C. After this addition, the resulting solution was heated to 95-99C. 228g of allyl glycidyl ether (AGE, 2 mol) were added to the flask in 3 hours. After this addition, the mixture was stirred for an additional 15 minutes at 99C and then the volatiles were removed at
4 ~m Hg and a pot temperature of 120~C. This resulted in a thick, white slurry, The slurry was cooled to room temperature and 250 ml of acetone were added. The mixture was stirred fnr 1 hour and filtered. The filtrate solution was vacuum distilled to remove the acetone. A thick, slightly yellow solution (2359) was obtained.
The solution contained the desired phosphite product and 6 glyceryl allyl ether (GAE a hydrolysate of AGE) as verified by 31p NMR and IR spectroscopy. The solution was further purified by a continuous water/e~hyl acetate extraction. The product was a viscous yellow liquid and weighed 133.29. The purity of this material was approximately 90~.
The 31p NMR spectrum showed two major resonances at 8.7 ppm and 7.3 ppm downfield from external phosphoric acid. These were assigned to the primary and secondary monosodium allyloxyhydroxy-propyl phosphites ~AHPP), respectively. The P-H coupling constant was approximately 620 H A trace of insrganic phosphite was noted at 4.3 ppm. Tne 13C NMR showed the AHPP at 64.5, 68.9, 70.3, 71.8, 11~.1 and 133.8 ppm downfield from external dioxane. The gl~ceryl allyl ether was detected at 63.2, 70.4, 70.8 and 71.6 ppm.
- The IR spectrum showed an intense P-H stret:ch at 2380 cm 1 and P=0 stretch at 1210 cm ~.
2~ Example 2 - Mixed Monomer Solution Preparation Utili~inq the apparatus and procedure described in Example 1, 160g of 50X sodium hydroxide ~2 mol), 1649 of phosphorous acid ~2 mol~ and 1209 of deionized water were charged to the reaction flask. 2289 of AGE ~2 mol) were then added over 3 1/2 hours at 97C. This resulted in a clear, dark yellow solution.
~ater was then removed by ~acuum distillation. The reaction mixture was cooled and 300 ml of ethyl acetate were added and stirred for 1 ~2~72 hour. The mixture was then filtered to remove the inorganic material. The filtrate was stripped of ethyl acetate. 310g of a thick, yellow material were obtained.
The structure of this material was verified by 13C NMR
and 31p NMR. The product contained about 30b (by weight) of the two AHPP isomers, 67% glyceryl allyl ether and 3~ monosodium phosphite.
~xample 3 - Mixed Monomer Solution Preparation Utilizing the apparatus and procedure described in 10 Example 1, 40.09 of sodium hydroxide (1 mol), 829 of phosphorous acid (1 mol~ and 91.19 of deionized water was charged to the flask.
1149 of AGE (1 mol) was then added over 2 1/2 hours while the temperature was maintained around 37~C. After stirring for an additional 25 minutes, the reaction mixture was distilled under vacuum to remove 1539 oF distillate. The resulting thick slurry was diluted to 40.3~ solids by the addition of deionized water. A clear - yellow solution was obtained.
The structure of the material obtained was determined by 13C NMR and 31p NMR. The material contained 3~ (by weight~ of the two AHPP isomers, 23~ glyceryl allyl ether and 42~ monosodium phosphite.
Example 4 - Mixed Monomer Solution Preparation Utilizing the apparatus and procedure described in Example 1, 50g of 50% sodium hydroxide (9.625 mol), 70.29 of 2~ potassium hydroxide (1.27 mol~, 102.59 of phosphorous acid (1.25 72~
mol) and 4509 of deionized water were charged to the reaction flask. 128.39 of AGE (1.125 mol) were then added over 90 minutes at room temperature. The reaction mixture was then heated to 80C and maintained for 3 1/2 hours resulting in a clear yellow solution.
The product was identified by 13C NMR and 31P NMR as containing mainly the primary AHPP isomer (70X yield), some unreacted AGE, glyceryl allyl ether and sodium-potassium phosphite.
Example 5 - Preparation of Acrylic Acid/Glycer 1 Allyl Ether/
Monosodium Allyloxy Hydroxypropyl ~ osphite Terpolymer Molar Ratio of 3i.2/1 A suitable flask was equipped with a condenser, addition funnel, overhead stirrer, thermometer, nitrogen blanket and an inlet for the initiator. 33.59 of acrylic acid (.465 mol) was placed into the additional funnel. 1009 of the mixed monomer solution of Example 1 (33.8g~ 0.155 mol), 1049 of deionized water and 13.49 of isopropanol were charged to the flask. The resulting solution was then heated ~o reflux under a nitrogen blanket. An initiator solution containing 31% sodium persulfate in deionized water was prep?red separately and sparged with nitrogen. The initiator 2Q solution (9.9g) was then added to the reaction flask along with the acrylic acid over a period of 2 hours. One hour after th;s addition was complete, 0.19 of 70~ t-butylhydrogen peroxide dissolved in 0.99 of deioni~ed water was added to the reaction mixture. The resulting mixture was heated for one more hour at reflux (89C) followed by 2.~ ~he r~moval of 43.19 of an isopropanol/~ater azeotrope. The reaction mixture was then cooled to room temperature and 19.09 of a 50~ caustic solution were added.
~2~7~Z
The copolymer solution, after being diluted with water to 25% solids had a Brookfield viscosity of 11.~ cps. The resulting product was a slightly yellow clear solution. The structure of the terpolymer was verified by 13C NMR. The spectrum was characterized by a broad, poly (acrylic acid)-type backbone and complex C-O region (62-74 ppm) and contained no evidence of unreacted monomers. The lp NMR spectrum was similar to that described in Example 1 except there was a broadening in the width of the peaks which indicates that the AHPP was incorporated into the 1 0 polymerO
Example 6 - M/GAE/AHPP Molar Ratio of 3/1/.3 Utilizing the apparatus and procedur~ as described in Example 5, 70g of the product recovered in Example 2 were dissolved in 2369 of water and added to the flask. 72g of acrylic acid (1 ~5 mol) and 21.39 of the initiator solution were used to complete the polymerization. The polymer solution, after being diluted to 25%
solids, had a Brookfield viscosity of 14.5 cps. The structure of the terpolymer was verified by 13C NMR.
Example 7 - AA/GAF/A~PP Molar Ratio of 4/1/2 Utilizing the apparatus and procedure as described in Example 5, 507~7g of the product recovered in Example 4 were added to the flask ~o additional water was necessary and the isopropanol was reduced to 35g. 72.19 o~ acrylic acid ~1.0 mol) and 21.3g of the in~tiator solution were used to complete the polymerization.
The polymer solution, after being diluted to 25~ solids, had a Brookfield viscosity of 11.0 cps. The structure of the terpolymer was Yerified b~ 13C NMR. Low levels of unreacted monomer could a7so be detected.
`~ 2 ~ 7~ Z
Example 8 - M/GAE/AHPP Molar Ratio of_6.7/1/1 Utilizing the apparatus and procedure as described in Example 5, 113.69 of the product from Example 3 (40.3% solids) was dissolved in 69.99 of water and added to the flask. 369 of acrylic acid (0.5 mol) and 13.39 of the initiator solution were used to complete the polymerization.
The polymer solution, after being diluted to 25% solids, had a Brookfield viscosity of 13.0 cps. The structure of the terpolymer was verified by 13C NMR and 31p NMR. The inorganic monosodium phosphite accounted for 20~ of the solids present.
Deposit Control Activity One method of evaluating deposit control activity of a material consists of measuring its ability to prevent bulk phase precipitation of a salt at conditions for which the salt would normally precipitate. It is additionally important to recognize that the material being evaluated is tested at "substoichiometric"
concentrations. That is, typical molar ratios of precipitating cation to the material being evaluated are on the order of 20:1 and much greater. Consequently, stoichiometric sequestration is not the route through which bulk phase precipitation is prevented. This well known phenomenon i5 also called "threshold" treatment and is widely practiced in water treatment technologw for the prevention of scale (salt) deposits from forming on various surfaces. In the results that follow, calcium phosphate and calcium carbonate salts commonly found in industrial water systems under various conditions have been selected as precipitants. The polymers of the present 7;~9~
invention have been evaluated for their ability to prevent precipi-tation (i.e., inhibit crystallization) of these salts. The results are expressed as "percent inhibition", positive values indicate that the stated percentage of precipitate was prevented from being formed. Except as where noted to the contrary, the following conditions, solutions, and testing procedure were utilized to perform the inhibition tests, the results of which are reported herein in Tables I and II.
3~2~72~
CALCIUM CARBONATE INHIBITION
Conditions Solutions pH = 9.0, 8.5 3.25g CaC122H20/liter DI H20 T = 70C 2.489 Na2C03/liter DI H20 17 hour equilibrium 1,105 ppm Ca+2 as CaC03 702 ppm C03 Procedure 1) Add 50 ml CaC12 2H20 pre-adjusted to pH 9Ø
2) Add treatment.
3) Add 50 ml Na2C03 pre-adjusted to pH 9Ø
43 Heat 5 hours at 70C water bath. Remove and cool to room ~emperature.
The solution contained the desired phosphite product and 6 glyceryl allyl ether (GAE a hydrolysate of AGE) as verified by 31p NMR and IR spectroscopy. The solution was further purified by a continuous water/e~hyl acetate extraction. The product was a viscous yellow liquid and weighed 133.29. The purity of this material was approximately 90~.
The 31p NMR spectrum showed two major resonances at 8.7 ppm and 7.3 ppm downfield from external phosphoric acid. These were assigned to the primary and secondary monosodium allyloxyhydroxy-propyl phosphites ~AHPP), respectively. The P-H coupling constant was approximately 620 H A trace of insrganic phosphite was noted at 4.3 ppm. Tne 13C NMR showed the AHPP at 64.5, 68.9, 70.3, 71.8, 11~.1 and 133.8 ppm downfield from external dioxane. The gl~ceryl allyl ether was detected at 63.2, 70.4, 70.8 and 71.6 ppm.
- The IR spectrum showed an intense P-H stret:ch at 2380 cm 1 and P=0 stretch at 1210 cm ~.
2~ Example 2 - Mixed Monomer Solution Preparation Utili~inq the apparatus and procedure described in Example 1, 160g of 50X sodium hydroxide ~2 mol), 1649 of phosphorous acid ~2 mol~ and 1209 of deionized water were charged to the reaction flask. 2289 of AGE ~2 mol) were then added over 3 1/2 hours at 97C. This resulted in a clear, dark yellow solution.
~ater was then removed by ~acuum distillation. The reaction mixture was cooled and 300 ml of ethyl acetate were added and stirred for 1 ~2~72 hour. The mixture was then filtered to remove the inorganic material. The filtrate was stripped of ethyl acetate. 310g of a thick, yellow material were obtained.
The structure of this material was verified by 13C NMR
and 31p NMR. The product contained about 30b (by weight) of the two AHPP isomers, 67% glyceryl allyl ether and 3~ monosodium phosphite.
~xample 3 - Mixed Monomer Solution Preparation Utilizing the apparatus and procedure described in 10 Example 1, 40.09 of sodium hydroxide (1 mol), 829 of phosphorous acid (1 mol~ and 91.19 of deionized water was charged to the flask.
1149 of AGE (1 mol) was then added over 2 1/2 hours while the temperature was maintained around 37~C. After stirring for an additional 25 minutes, the reaction mixture was distilled under vacuum to remove 1539 oF distillate. The resulting thick slurry was diluted to 40.3~ solids by the addition of deionized water. A clear - yellow solution was obtained.
The structure of the material obtained was determined by 13C NMR and 31p NMR. The material contained 3~ (by weight~ of the two AHPP isomers, 23~ glyceryl allyl ether and 42~ monosodium phosphite.
Example 4 - Mixed Monomer Solution Preparation Utilizing the apparatus and procedure described in Example 1, 50g of 50% sodium hydroxide (9.625 mol), 70.29 of 2~ potassium hydroxide (1.27 mol~, 102.59 of phosphorous acid (1.25 72~
mol) and 4509 of deionized water were charged to the reaction flask. 128.39 of AGE (1.125 mol) were then added over 90 minutes at room temperature. The reaction mixture was then heated to 80C and maintained for 3 1/2 hours resulting in a clear yellow solution.
The product was identified by 13C NMR and 31P NMR as containing mainly the primary AHPP isomer (70X yield), some unreacted AGE, glyceryl allyl ether and sodium-potassium phosphite.
Example 5 - Preparation of Acrylic Acid/Glycer 1 Allyl Ether/
Monosodium Allyloxy Hydroxypropyl ~ osphite Terpolymer Molar Ratio of 3i.2/1 A suitable flask was equipped with a condenser, addition funnel, overhead stirrer, thermometer, nitrogen blanket and an inlet for the initiator. 33.59 of acrylic acid (.465 mol) was placed into the additional funnel. 1009 of the mixed monomer solution of Example 1 (33.8g~ 0.155 mol), 1049 of deionized water and 13.49 of isopropanol were charged to the flask. The resulting solution was then heated ~o reflux under a nitrogen blanket. An initiator solution containing 31% sodium persulfate in deionized water was prep?red separately and sparged with nitrogen. The initiator 2Q solution (9.9g) was then added to the reaction flask along with the acrylic acid over a period of 2 hours. One hour after th;s addition was complete, 0.19 of 70~ t-butylhydrogen peroxide dissolved in 0.99 of deioni~ed water was added to the reaction mixture. The resulting mixture was heated for one more hour at reflux (89C) followed by 2.~ ~he r~moval of 43.19 of an isopropanol/~ater azeotrope. The reaction mixture was then cooled to room temperature and 19.09 of a 50~ caustic solution were added.
~2~7~Z
The copolymer solution, after being diluted with water to 25% solids had a Brookfield viscosity of 11.~ cps. The resulting product was a slightly yellow clear solution. The structure of the terpolymer was verified by 13C NMR. The spectrum was characterized by a broad, poly (acrylic acid)-type backbone and complex C-O region (62-74 ppm) and contained no evidence of unreacted monomers. The lp NMR spectrum was similar to that described in Example 1 except there was a broadening in the width of the peaks which indicates that the AHPP was incorporated into the 1 0 polymerO
Example 6 - M/GAE/AHPP Molar Ratio of 3/1/.3 Utilizing the apparatus and procedur~ as described in Example 5, 70g of the product recovered in Example 2 were dissolved in 2369 of water and added to the flask. 72g of acrylic acid (1 ~5 mol) and 21.39 of the initiator solution were used to complete the polymerization. The polymer solution, after being diluted to 25%
solids, had a Brookfield viscosity of 14.5 cps. The structure of the terpolymer was verified by 13C NMR.
Example 7 - AA/GAF/A~PP Molar Ratio of 4/1/2 Utilizing the apparatus and procedure as described in Example 5, 507~7g of the product recovered in Example 4 were added to the flask ~o additional water was necessary and the isopropanol was reduced to 35g. 72.19 o~ acrylic acid ~1.0 mol) and 21.3g of the in~tiator solution were used to complete the polymerization.
The polymer solution, after being diluted to 25~ solids, had a Brookfield viscosity of 11.0 cps. The structure of the terpolymer was Yerified b~ 13C NMR. Low levels of unreacted monomer could a7so be detected.
`~ 2 ~ 7~ Z
Example 8 - M/GAE/AHPP Molar Ratio of_6.7/1/1 Utilizing the apparatus and procedure as described in Example 5, 113.69 of the product from Example 3 (40.3% solids) was dissolved in 69.99 of water and added to the flask. 369 of acrylic acid (0.5 mol) and 13.39 of the initiator solution were used to complete the polymerization.
The polymer solution, after being diluted to 25% solids, had a Brookfield viscosity of 13.0 cps. The structure of the terpolymer was verified by 13C NMR and 31p NMR. The inorganic monosodium phosphite accounted for 20~ of the solids present.
Deposit Control Activity One method of evaluating deposit control activity of a material consists of measuring its ability to prevent bulk phase precipitation of a salt at conditions for which the salt would normally precipitate. It is additionally important to recognize that the material being evaluated is tested at "substoichiometric"
concentrations. That is, typical molar ratios of precipitating cation to the material being evaluated are on the order of 20:1 and much greater. Consequently, stoichiometric sequestration is not the route through which bulk phase precipitation is prevented. This well known phenomenon i5 also called "threshold" treatment and is widely practiced in water treatment technologw for the prevention of scale (salt) deposits from forming on various surfaces. In the results that follow, calcium phosphate and calcium carbonate salts commonly found in industrial water systems under various conditions have been selected as precipitants. The polymers of the present 7;~9~
invention have been evaluated for their ability to prevent precipi-tation (i.e., inhibit crystallization) of these salts. The results are expressed as "percent inhibition", positive values indicate that the stated percentage of precipitate was prevented from being formed. Except as where noted to the contrary, the following conditions, solutions, and testing procedure were utilized to perform the inhibition tests, the results of which are reported herein in Tables I and II.
3~2~72~
CALCIUM CARBONATE INHIBITION
Conditions Solutions pH = 9.0, 8.5 3.25g CaC122H20/liter DI H20 T = 70C 2.489 Na2C03/liter DI H20 17 hour equilibrium 1,105 ppm Ca+2 as CaC03 702 ppm C03 Procedure 1) Add 50 ml CaC12 2H20 pre-adjusted to pH 9Ø
2) Add treatment.
3) Add 50 ml Na2C03 pre-adjusted to pH 9Ø
43 Heat 5 hours at 70C water bath. Remove and cool to room ~emperature.
5) Filter 5 mls through 0.2u filters.
63 Adjust samples to pH 1.0 with conc. HCl ( 19 Conc. HCl~.
7) Allow to stand at least 15 minutes.
8~ Dilute to 50 mls with DI H20.
~ Bring pH to 12.0 with NaOH.
10~ Add Ca+2 indicator (1 level).
2~ Titrate with EDTA to purple-violet endpoint.
Calculation:
ml EDTA titrated (treated) - ml 'DTA titrated ~control) Inhi~ition ml EDTA titrated ~Ca 2 stock-ml EDTA titrated (control) x 100 1 2 ~7 CALCIUM PHOSPHATE INHIBITION PROCEDURE
Conditions Solutions T = 70C 3S.76 CaC12 2H20/liter DIH20 pH = 8.5 0.4482g Na2HP04/li~er DIH20 17 hour equilibration Ca+2 = 250 ppm as CaC03 P04 ~3 = 6 ppm Procedure 1~ To about 1800 ml DIH20 in a 2 liter volumetric flask, add 20 ml of CaC12 2H20 solution followed by 2 drops of conc.
HCl.
2) Add 40 ml of Na2HP04 solution.
3) Bring volume to 2 liters with DI water.
4) Place 100 ml aliquots of solution in 4 oz glass bottles.
5) Add treatment.
63 Adjust samples to pH 1.0 with conc. HCl ( 19 Conc. HCl~.
7) Allow to stand at least 15 minutes.
8~ Dilute to 50 mls with DI H20.
~ Bring pH to 12.0 with NaOH.
10~ Add Ca+2 indicator (1 level).
2~ Titrate with EDTA to purple-violet endpoint.
Calculation:
ml EDTA titrated (treated) - ml 'DTA titrated ~control) Inhi~ition ml EDTA titrated ~Ca 2 stock-ml EDTA titrated (control) x 100 1 2 ~7 CALCIUM PHOSPHATE INHIBITION PROCEDURE
Conditions Solutions T = 70C 3S.76 CaC12 2H20/liter DIH20 pH = 8.5 0.4482g Na2HP04/li~er DIH20 17 hour equilibration Ca+2 = 250 ppm as CaC03 P04 ~3 = 6 ppm Procedure 1~ To about 1800 ml DIH20 in a 2 liter volumetric flask, add 20 ml of CaC12 2H20 solution followed by 2 drops of conc.
HCl.
2) Add 40 ml of Na2HP04 solution.
3) Bring volume to 2 liters with DI water.
4) Place 100 ml aliquots of solution in 4 oz glass bottles.
5) Add treatment.
6) Adjust pH as desired.
7~ Place in 70C water bath and equilibrate for 17 hours.
8) Remove samples and filter while hot through 0.2 u filters.
9) Cool to room temperature and take Absorbance measurements using Leit~ photometer (640nm).
Preparation for Leitz a. 5 mls filtrate b. 10 mls Molybdate Reagent ~ 7 2 c. 1 dipper Stannous Reagent d. Swirl 1 minute, pour into Leitz curvette; wait 1 minute before reading.
Preparation for Leitz a. 5 mls filtrate b. 10 mls Molybdate Reagent ~ 7 2 c. 1 dipper Stannous Reagent d. Swirl 1 minute, pour into Leitz curvette; wait 1 minute before reading.
10) Using current calibration curve (Absorbance vs ppm P04~3) find ppm P04-3 of each sample.
Calculation:
Inhibition = ppm P04~3 (treated) - ppm P04~3 (control) x 100 ppm P04~3 (stock) - ppm P04~3 (control) Table I
Calcium Phosphate Inhibition Conditions: 600 ppm Ca as CaC03, 12 ppm P04~3, pH 7.0, 70C, 17 Hour Equil,bration, 2mM NaHC03 ~ Inhibition Treatment Concentrations (ppm active) Treatment 5 10 20 . Copolymer Example 5 13.3 13.7 91.5 Example 6 10.0 7.9 89.6 Example 7 4.4 10.7 3?,9 Example 8 2.0 6.2 28.1 ?O Polyacylic Acid mw = 5,000 4.7 9.7 53.8 ~ 7~ 2 Table II
Calcium Carbonate Inhibition Conditions: 1105 ppm Ca+2 as CaC03, 702 ppm C03 -2, pH 9.0, 70C, 17 Hour Equilibration % Inhibition Treatment Concentrations (ppm active) Treatment 5 10 20 Copolymer Example 5 7.4 27.5 44.2 Example 6 2.2 19.1 37.2 Example 7 6.9 9.3 26.6 Example 8 7.8 18.0 35.9 Polyacrylic Acid mw = 5,000 15.3 30.5 41.5 In order to demonstrate the effectiveness of the polymers o~ the invention in dispersing suspended particulate matter, the follo~ing procedures, using Fe203 and montmorillonmite clay as suspended solids, were undertaken. Results appear in Tables III
and IY. In the results, it is noted that increasing A ~T values indicate better treatment as more.particles remain suspended in the 2U aqueous medium.
~2~2~
Fe203 Dispersion Procedure Conditions: Solutions:
T = 25C 0.1% solution Fe203 in D.I. H20 pH = 7.5 3.68g CaC12 2H2O/100 ml DI H20 Procedure ( 1) Prepare a suspension of 0.1% Fe203 in DI H20.
2) Adjust hardness to 200 ppm Ca~2 as CaC03 using CaC12 -2H20 solution - 8 ml/1000 ml of Fe203 solution.
( 3) Using overhead mixer, mix suspension 1/2 hour at 1000 rpms.
0 ( 4) Remove solution to magnetic stirrer and adjust to pH 7.5 (about 20 minutes to stabilize pH).
( 5) Return solution to overhead mixer.
I 6) Take 90 ml aliquots of suspension and place 4 oz. glass bottle.
~ 7) Add treatment and DI water to bring total volume to 100 ml.
5 1 8) Cap bottle, invert several times and place on reciprocating shaker at a moderate speed of about 40 spm for 1/2 hour.
9) Place on vibration-proof surface and allow to stand 18 hours.
(10) ~ithout disturbing settled phase, pipet the top 40 mls off the sample. Place in a cell and read ~T tat 415 nm).
Calculation ~T = ~T (control) - ~T (treated) 7~
Montmorillonite Dispersion Procedure Similar to that repor~ed hereinabove for Fe203 wi~h the obvious exception that montmorillonite clay was substituted for Fe203 ~
Table III
Montmorillonite Dispersions Conditions: 200 ppm Ca2~ as CaC03, pH 7.0, 1000 ppm Montmorillonite, 17 hour equilibration ~ % Transmittance -Treatment Concen~rations (ppm ac~ive~
Trea~lent 5 10 ?0 Copolymer Example 510.0 28.8 35.8 Example 65.5 20.8 36.5 Example 73.5 9.0 17.3 Example 314.5 26.0 33.3 Polyacylic Acid - mw = 5~000 15.3 22.0 29.0 Table IY
Ferric Oxide Dis~rsions Conditions- 200 ppm Ca as CaC03, 300 ppm Fe203, 45~C, pH 7.0 18 Hour Equilibration, 10 mM NaHC03 ~,24729h - 2~ -L~% Transmittance ..
Treatment Concentrations (ppm active) Treatment 5 10 20 Copolymer S Example 5 8.3 10.5 12.5 Example 6 6.8 9.3 11.3 Example 7 3.3 10.0 12.8 Example 8 7.0 9.3 12.0 Polyacrylic Acid mw = 5,000 4.3 8.5 16.5 Discussion The examples demonstrate that the polymers of the presen~
invention are effectiYe in inhibiting the formation of calcium phospha~e and calciwm carbonate, both o~ which are commonly encountered in industrial water systems, such as cooling water systems. Further, the polymers effectively disperse iron oxide and clay which are sometimes encountered as troublesome fouling species.
Passivation -Although preliminary data suggests that the polymers oi the inYention, when used singly, may not adequately inhibit corrosion, ~he demonstrated efficacy sf the polymers in inhibiting calcium phosphate precipitation is very important. For instance, one successfully established cooling water treatment method provides a passi~ated oxide film on metal surfaces in contact with the aqueous medium via addition of orthophosphate, organo-phosphonate and an acrylic acid/hydroxylated alkyl acrylate copolymer. Deta~ls o~ such method are disclosed in U.S. Patent 4,303,5~8 (May et al).
'72~3~
The entire content of this patent is hereby incorporated by reference. Based upon the deposit control efficacy shown by the instant copolymers, as well as the minimum corrosion rates displayed herein in the recirculator studies, it is thought that the subject copolymers can be substituted for the polymers disclosed in the aforementioned May et al patent so as to proYide the important passivated oxide film on the desired metal surfaces.
As is stated in that patent, the passive oxide film is provided on metal surfaces in contact with the aqueous medium without substantial attendant deposition formed thereon. A
composition containing polymer and orthophosphate and optionally but preferably a phosphonate, polyphosphate and copper corrosion inhibitors is used in order to achieYe such passivation. A typical composition contains on a weight ratio basis of polymer to orthophosphate expressed as P04 ~ of about 1:8 to 4:1 and preferably about 1:6 to 2:1. When a polyphosphate* is included, the weight ratio of orthophosphate to polyphosphate on a P04 basis is 15:1 to 1:3, and preferably 2.3:1 to 1:1. Similarly, if ~ the organo-phosphonate is included, the ratio of the orthophosphate to-the phosphonate expressed as P4 to po4 is 1:2 to 13:1, and pre~erably 2:1 to 8:1. Any copper corrosion inhibitor may be incl~ded in the composition (o.01 to 5~ by weight) in an amount ~hich will be effective for controlling the copper corrosion in a given system: 0.05 to 10 parts per million and preferably 0.5 to 5 2.5 parts per million. Similarly, zinc salts may be included if addi~ional protection is needed.
*Betz Handbook of Industrial Water Conditioning, ~th edition, 1962, pages 3g4-396, 8etz Laboratories, Inc., Trevose, PA.
~72~
In treating the aqueous systems to provide such passiva-tion, the following dosages in parts per million parts of water in said aqueous systems of the respective ingredients are desirable, with the dosages, of course, being based upon the severity of the corrosion problem foreseen or experienced:
orthophosphate (expressed as P04 ): 2 to 50 parts per million parts of water (ppm) and preferably 6 to 30 ppm;
polymer: 0.3 to 120 ppm and preferably 3 to 25 ppm;
polyphosphate (expressed as P04 ): 0.1 to 30, and preferably 3 to 10, parts per million parts of water, phosphonate (expressed as P04 ): 0.04 to 20, and preferably 1 to 6, parts per million parts of water.
The preferred rate of application of this treatment to cooling water systems and the ratios of various components depends on the calcium concentration of the cooling water. The treatment is preferably applied in waters having between 15 ppm and 1,000 ppm calcium. Within this range the weight ratio of calcium to orthophosphate is varied from 1:1 to 83.3:1, the ~eight ratio of 2~ polymer to orthophosphate is varied from 1:3 to 1.5:1.
The orthophosphate which is critical to passivation aspect of the present invention is generally obtained by direct addition. However, it is understood that ~he orthophospha~e can also arise due to reversion of either inorganic polyphosphates or the organo-phosphonates, or any other appropriate source or precursor thereof.
~ 7 2 The above dosages represent the most desirable ranges since most systems will be ~reatable therewith. Higher dosages are permissible when the situation demands, but of course are most costly. The effectiveness of the inventive treatments are dependent 5 upon the aqueous medium having a pH of 5.5 and above, and preferably 6.5 to 9.5, and containing calcium ion concentrations, preferably about 15 parts per million parts of water. Below this range, it may be necessary for overall effectiveness to add metallic ions such as zinc, nickel, chromium, etc. as described in column 3, lines 4 to 24 of U.S. Pat. No. 3,837,803.
Comparative Example The specific product of U.S. Patent 4,500,693 Example 2, was prepared as follows: 70.64g of allyl glyceryl ether (0.535 mol3 were charged to a reaction flask under nitrogen. 38.09 of phosphorus pentoxide (0.268 mol) were then added over 65 minutes.
The reaction mixture was warmed to 65C over 20 minutes and maintained at that temperature for 160 minutes. The product was cooled to room temperature followed by the addition of 1759 of deionized water. 70.59 of this prsduct were then copolymerized with 404.~g of a 3P~ potassium methacrylate solution. This was done by adding the monomers simultaneously with 185.19 of a 3% ammonium persulfate solution to a flask con~aining 73.99 sf water under nitrogen a~mosphere. The addition took 3 1/2 hours and was carried out at 90~. The yellow brown colored copolymer solution had a 2~ Brookfield viscosity of 23.5 cps at 20.8~ solids.
This polymer was then tested for calcium phosphate inhibition and was contrasted to the Example 6 polymer of the present invention.
~2~1'7Z~
COMPARATIVE TEST
Calcium Phosphate Inhibition 600 ppm Ca as CaC03, 12 ppm P04, pH 7, 2mM NaHC03, 70C, 18 hours equilibrium 5 Treatment % Inhibition 5 ppm 10 ppm 15 ppm20 ppm Active Active Active Active Acryl ic Acid/2-hydroxypropyl Acrylate Mn ~ 2~000 M:HPA molar ratio 3:1 14~3 42.9 92.9 100.0 xample 6 11.0 41.8 99.8 lOO.U
U.S. Patent 4,500,693 Example 2 13.7 36.8 62.6 73. 7 While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications ~hich are within the true spirit and scope of ~he - 2a present inven~ion.
Calculation:
Inhibition = ppm P04~3 (treated) - ppm P04~3 (control) x 100 ppm P04~3 (stock) - ppm P04~3 (control) Table I
Calcium Phosphate Inhibition Conditions: 600 ppm Ca as CaC03, 12 ppm P04~3, pH 7.0, 70C, 17 Hour Equil,bration, 2mM NaHC03 ~ Inhibition Treatment Concentrations (ppm active) Treatment 5 10 20 . Copolymer Example 5 13.3 13.7 91.5 Example 6 10.0 7.9 89.6 Example 7 4.4 10.7 3?,9 Example 8 2.0 6.2 28.1 ?O Polyacylic Acid mw = 5,000 4.7 9.7 53.8 ~ 7~ 2 Table II
Calcium Carbonate Inhibition Conditions: 1105 ppm Ca+2 as CaC03, 702 ppm C03 -2, pH 9.0, 70C, 17 Hour Equilibration % Inhibition Treatment Concentrations (ppm active) Treatment 5 10 20 Copolymer Example 5 7.4 27.5 44.2 Example 6 2.2 19.1 37.2 Example 7 6.9 9.3 26.6 Example 8 7.8 18.0 35.9 Polyacrylic Acid mw = 5,000 15.3 30.5 41.5 In order to demonstrate the effectiveness of the polymers o~ the invention in dispersing suspended particulate matter, the follo~ing procedures, using Fe203 and montmorillonmite clay as suspended solids, were undertaken. Results appear in Tables III
and IY. In the results, it is noted that increasing A ~T values indicate better treatment as more.particles remain suspended in the 2U aqueous medium.
~2~2~
Fe203 Dispersion Procedure Conditions: Solutions:
T = 25C 0.1% solution Fe203 in D.I. H20 pH = 7.5 3.68g CaC12 2H2O/100 ml DI H20 Procedure ( 1) Prepare a suspension of 0.1% Fe203 in DI H20.
2) Adjust hardness to 200 ppm Ca~2 as CaC03 using CaC12 -2H20 solution - 8 ml/1000 ml of Fe203 solution.
( 3) Using overhead mixer, mix suspension 1/2 hour at 1000 rpms.
0 ( 4) Remove solution to magnetic stirrer and adjust to pH 7.5 (about 20 minutes to stabilize pH).
( 5) Return solution to overhead mixer.
I 6) Take 90 ml aliquots of suspension and place 4 oz. glass bottle.
~ 7) Add treatment and DI water to bring total volume to 100 ml.
5 1 8) Cap bottle, invert several times and place on reciprocating shaker at a moderate speed of about 40 spm for 1/2 hour.
9) Place on vibration-proof surface and allow to stand 18 hours.
(10) ~ithout disturbing settled phase, pipet the top 40 mls off the sample. Place in a cell and read ~T tat 415 nm).
Calculation ~T = ~T (control) - ~T (treated) 7~
Montmorillonite Dispersion Procedure Similar to that repor~ed hereinabove for Fe203 wi~h the obvious exception that montmorillonite clay was substituted for Fe203 ~
Table III
Montmorillonite Dispersions Conditions: 200 ppm Ca2~ as CaC03, pH 7.0, 1000 ppm Montmorillonite, 17 hour equilibration ~ % Transmittance -Treatment Concen~rations (ppm ac~ive~
Trea~lent 5 10 ?0 Copolymer Example 510.0 28.8 35.8 Example 65.5 20.8 36.5 Example 73.5 9.0 17.3 Example 314.5 26.0 33.3 Polyacylic Acid - mw = 5~000 15.3 22.0 29.0 Table IY
Ferric Oxide Dis~rsions Conditions- 200 ppm Ca as CaC03, 300 ppm Fe203, 45~C, pH 7.0 18 Hour Equilibration, 10 mM NaHC03 ~,24729h - 2~ -L~% Transmittance ..
Treatment Concentrations (ppm active) Treatment 5 10 20 Copolymer S Example 5 8.3 10.5 12.5 Example 6 6.8 9.3 11.3 Example 7 3.3 10.0 12.8 Example 8 7.0 9.3 12.0 Polyacrylic Acid mw = 5,000 4.3 8.5 16.5 Discussion The examples demonstrate that the polymers of the presen~
invention are effectiYe in inhibiting the formation of calcium phospha~e and calciwm carbonate, both o~ which are commonly encountered in industrial water systems, such as cooling water systems. Further, the polymers effectively disperse iron oxide and clay which are sometimes encountered as troublesome fouling species.
Passivation -Although preliminary data suggests that the polymers oi the inYention, when used singly, may not adequately inhibit corrosion, ~he demonstrated efficacy sf the polymers in inhibiting calcium phosphate precipitation is very important. For instance, one successfully established cooling water treatment method provides a passi~ated oxide film on metal surfaces in contact with the aqueous medium via addition of orthophosphate, organo-phosphonate and an acrylic acid/hydroxylated alkyl acrylate copolymer. Deta~ls o~ such method are disclosed in U.S. Patent 4,303,5~8 (May et al).
'72~3~
The entire content of this patent is hereby incorporated by reference. Based upon the deposit control efficacy shown by the instant copolymers, as well as the minimum corrosion rates displayed herein in the recirculator studies, it is thought that the subject copolymers can be substituted for the polymers disclosed in the aforementioned May et al patent so as to proYide the important passivated oxide film on the desired metal surfaces.
As is stated in that patent, the passive oxide film is provided on metal surfaces in contact with the aqueous medium without substantial attendant deposition formed thereon. A
composition containing polymer and orthophosphate and optionally but preferably a phosphonate, polyphosphate and copper corrosion inhibitors is used in order to achieYe such passivation. A typical composition contains on a weight ratio basis of polymer to orthophosphate expressed as P04 ~ of about 1:8 to 4:1 and preferably about 1:6 to 2:1. When a polyphosphate* is included, the weight ratio of orthophosphate to polyphosphate on a P04 basis is 15:1 to 1:3, and preferably 2.3:1 to 1:1. Similarly, if ~ the organo-phosphonate is included, the ratio of the orthophosphate to-the phosphonate expressed as P4 to po4 is 1:2 to 13:1, and pre~erably 2:1 to 8:1. Any copper corrosion inhibitor may be incl~ded in the composition (o.01 to 5~ by weight) in an amount ~hich will be effective for controlling the copper corrosion in a given system: 0.05 to 10 parts per million and preferably 0.5 to 5 2.5 parts per million. Similarly, zinc salts may be included if addi~ional protection is needed.
*Betz Handbook of Industrial Water Conditioning, ~th edition, 1962, pages 3g4-396, 8etz Laboratories, Inc., Trevose, PA.
~72~
In treating the aqueous systems to provide such passiva-tion, the following dosages in parts per million parts of water in said aqueous systems of the respective ingredients are desirable, with the dosages, of course, being based upon the severity of the corrosion problem foreseen or experienced:
orthophosphate (expressed as P04 ): 2 to 50 parts per million parts of water (ppm) and preferably 6 to 30 ppm;
polymer: 0.3 to 120 ppm and preferably 3 to 25 ppm;
polyphosphate (expressed as P04 ): 0.1 to 30, and preferably 3 to 10, parts per million parts of water, phosphonate (expressed as P04 ): 0.04 to 20, and preferably 1 to 6, parts per million parts of water.
The preferred rate of application of this treatment to cooling water systems and the ratios of various components depends on the calcium concentration of the cooling water. The treatment is preferably applied in waters having between 15 ppm and 1,000 ppm calcium. Within this range the weight ratio of calcium to orthophosphate is varied from 1:1 to 83.3:1, the ~eight ratio of 2~ polymer to orthophosphate is varied from 1:3 to 1.5:1.
The orthophosphate which is critical to passivation aspect of the present invention is generally obtained by direct addition. However, it is understood that ~he orthophospha~e can also arise due to reversion of either inorganic polyphosphates or the organo-phosphonates, or any other appropriate source or precursor thereof.
~ 7 2 The above dosages represent the most desirable ranges since most systems will be ~reatable therewith. Higher dosages are permissible when the situation demands, but of course are most costly. The effectiveness of the inventive treatments are dependent 5 upon the aqueous medium having a pH of 5.5 and above, and preferably 6.5 to 9.5, and containing calcium ion concentrations, preferably about 15 parts per million parts of water. Below this range, it may be necessary for overall effectiveness to add metallic ions such as zinc, nickel, chromium, etc. as described in column 3, lines 4 to 24 of U.S. Pat. No. 3,837,803.
Comparative Example The specific product of U.S. Patent 4,500,693 Example 2, was prepared as follows: 70.64g of allyl glyceryl ether (0.535 mol3 were charged to a reaction flask under nitrogen. 38.09 of phosphorus pentoxide (0.268 mol) were then added over 65 minutes.
The reaction mixture was warmed to 65C over 20 minutes and maintained at that temperature for 160 minutes. The product was cooled to room temperature followed by the addition of 1759 of deionized water. 70.59 of this prsduct were then copolymerized with 404.~g of a 3P~ potassium methacrylate solution. This was done by adding the monomers simultaneously with 185.19 of a 3% ammonium persulfate solution to a flask con~aining 73.99 sf water under nitrogen a~mosphere. The addition took 3 1/2 hours and was carried out at 90~. The yellow brown colored copolymer solution had a 2~ Brookfield viscosity of 23.5 cps at 20.8~ solids.
This polymer was then tested for calcium phosphate inhibition and was contrasted to the Example 6 polymer of the present invention.
~2~1'7Z~
COMPARATIVE TEST
Calcium Phosphate Inhibition 600 ppm Ca as CaC03, 12 ppm P04, pH 7, 2mM NaHC03, 70C, 18 hours equilibrium 5 Treatment % Inhibition 5 ppm 10 ppm 15 ppm20 ppm Active Active Active Active Acryl ic Acid/2-hydroxypropyl Acrylate Mn ~ 2~000 M:HPA molar ratio 3:1 14~3 42.9 92.9 100.0 xample 6 11.0 41.8 99.8 lOO.U
U.S. Patent 4,500,693 Example 2 13.7 36.8 62.6 73. 7 While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications ~hich are within the true spirit and scope of ~he - 2a present inven~ion.
Claims (44)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Composition comprising a water soluble polymer, said polymer comprising repeat units characterized by the structure wherein E in the above formula is the residue obtained after polymerization of an .alpha.,B ethylenically unsaturated compound, R1 is a hydroxy substituted lower alkylene group having from about 1 - 6 carbon atoms or a non-substituted lower alkylene group having from about 1 - 6 carbon atoms; M is a water soluble cation or hydrogen, and the molar ratio g:h of about 30:1 to 1:20.
2. Composition as recited in claim 1 wherein E
comprises the residue remaining after polymerization of a compound or compounds selected from the group consisting of acrylic acid, acrylamide, maleic acid or anhydride, itaconic acid, methacrylic acid, lower alkyl (C1 - C6) ester or hydroxylated lower alkyl (C1 - C6) ester of said acids.
comprises the residue remaining after polymerization of a compound or compounds selected from the group consisting of acrylic acid, acrylamide, maleic acid or anhydride, itaconic acid, methacrylic acid, lower alkyl (C1 - C6) ester or hydroxylated lower alkyl (C1 - C6) ester of said acids.
3. Composition as recited in Claim 2 wherein E
comprises acrylic acid residue and 2-hydroxypropylacrylate residue.
comprises acrylic acid residue and 2-hydroxypropylacrylate residue.
4. Composition as recited in Claim 1 comprising another repeat unit comprising the structure wherein R2 comprises a hydroxylated lower alkyl (C1 - C6) group and the molar percentage of g in said polymer being between about 40 - 90 molar %, the molar percentage of h being between about 2 - 40 molar % and the molar percentage of i in said polymer being between about 1 - 35 molar %, the total of 9, h, and i equalling 100 molar %.
5. Composition as recited in Claim 4 wherein E
comprises acrylic acid residue, R1 comprises 2-hydroxypropylene and R2 comprises 2,3-dihydroxypropyl.
comprises acrylic acid residue, R1 comprises 2-hydroxypropylene and R2 comprises 2,3-dihydroxypropyl.
6. Composition as recited in Claim 1 further comprising a water soluble orthophosphate compound said composition comprising, on a weight ratio basis from about 1:8 to about 4:1 polymer:ortho-phosphate.
7. Composition as recited in Claim 6 further comprising a water soluble polyphosphate compound, the weight ratio of orthophosphate:polyphosphate being in the range of about 15:1 to 1:3.
8. Composition as recited in Claim 1 wherein M
comprises a member selected from the group consisting of H, Na, K, NH4+, an organic amine group, or an alkyl group having from 1 to 3 carbon atoms.
comprises a member selected from the group consisting of H, Na, K, NH4+, an organic amine group, or an alkyl group having from 1 to 3 carbon atoms.
9. Method of controlling the deposition of scale imparting precipitates on the structural parts of a system exposed to an aqueous medium containing scale imparting precipitates under deposit forming conditions, said method comprising adding to said aqueous medium, an effective amount for the purpose of an effective water soluble polymer characterized by the structure:
wherein E in the above formula is the residue obtained after polymerization of an .alpha., B ethylenically unsaturated compound, R1 is a hydroxy substituted lower alkylene group having from about 1 - 6 carbon atoms or a non-substituted lower alkylene group having from about 1 - 6 carbon atoms; M is a water soluble cation or hydrogen, and the molar ratio g:h of about 30:1 to 1:20.
wherein E in the above formula is the residue obtained after polymerization of an .alpha., B ethylenically unsaturated compound, R1 is a hydroxy substituted lower alkylene group having from about 1 - 6 carbon atoms or a non-substituted lower alkylene group having from about 1 - 6 carbon atoms; M is a water soluble cation or hydrogen, and the molar ratio g:h of about 30:1 to 1:20.
10. Method as recited in Claim 9 wherein E comprises the residue remaining after polymerization of a compound or compounds selected from the group consisting of acrylic acid, acrylamide, maleic acid or anhydride, itaconic acid, methacrylic acid, lower alkyl (C1 - C6) ester or hydroxylated lower alkyl (C1 - C6) ester of said acids.
11. Method as recited in Claim 10 wherein E comprises acrylic acid residue and 2-hydroxypropylacrylate residue.
12. Method as recited in Claim 9 wherein said polymer comprises another repeat unit comprising the structure wherein R2 comprises a hydroxylated lower alkyl (C1 - C6) group and the molar percentage of g in said polymer being between about 40 - 90 molar %, the molar percentage of h being between about 2 - 40 molar % and the molar percentage of i in said polymer being between about 1 - 35 molar %, the total of g, h, and i equalling 100 molar %.
13. Method as recited in Claim 12 wherein E comprises acrylic acid residue, R1 comprises 2-hydroxypropylene and R2 comprises 2,3-dihydroxypropyl.
14. Method as recited in Claim 9 wherein M comprises a member selected from the group consisting of H, Na, K, NH4+, an organic amine group, or an alkyl group having from 1 to 3 carbon atoms.
15. Method as recited in Claim 9 wherein said water soluble polymer is added to said aqueous medium in an amount of from about 0.1 - 500 parts polymer based upon 1 million parts of said aqueous medium.
16. Method as recited in Claim 9 wherein said aqueous medium comprises a steam generating system.
17. Method as recited in Claim 9 wherein said aqueous medium comprises a cooling water system.
18. Method as recited in Claim 9 wherein said aqueous medium comprises a gas scrubbing system.
19. Method as recited in Claim 9 wherein said scale imparting precipitates comprise calcium phosphate or calcium carbonate.
20. Method as recited in Claim 17 wherein said scale imparting precipitates comprises calcium phosphate and wherein E
comprises acrylic acid or water soluble salt thereof, and R1 comprises 2-hydroxypropylene.
comprises acrylic acid or water soluble salt thereof, and R1 comprises 2-hydroxypropylene.
21. Method of dispersing and maintaining dispersed suspended particulate matter in an aqueous medium, said particulate matter being selected from the group consisting of clay and iron oxide and mixtures thereof, said method comprising adding to said aqueous medium an effective amount of an effective water soluble polymer for the purpose, said polymer characterized by the formula:
wherein E in the above formula is the residue obtained after polymerization of an .alpha., .beta. ethylenically unsaturated compound, R1 is a hydroxy substituted lower alkyl group having from about 1 - 6 carbon atoms or a non-substituted lower alkyl group having from about 1 - 6 carbon atoms; M is a water soluble cation or hydrogen, and the molar ratio g:h of about 30:1 to 1:20.
wherein E in the above formula is the residue obtained after polymerization of an .alpha., .beta. ethylenically unsaturated compound, R1 is a hydroxy substituted lower alkyl group having from about 1 - 6 carbon atoms or a non-substituted lower alkyl group having from about 1 - 6 carbon atoms; M is a water soluble cation or hydrogen, and the molar ratio g:h of about 30:1 to 1:20.
22. Method as recited in Claim 21 wherein E comprises the residue remaining after polymerization of a compound or compounds selected from the group consisting of acrylic acid, acrylamide, maleic acid or anhydride, itaconic acid, methacrylic acid, lower alkyl (C1 - C6) ester or hydroxylated lower alkyl (C1 - C6) ester of said acids.
23. Method as recited in Claim 22 wherein E comprises acrylic acid residue and 2-hydroxypropylacrylate residue.
24. Method as recited in Claim 21 wherein said polymer comprises another repeat unit comprising the structure wherein R2 comprises a hydroxylated lower alkyl (C1 - C6) group and the molar percentage of g in said polymer being between about 40 - 90 molar %, the molar percentage of h being between about 2 - 40 molar % and the molar percentage of i in said polymer being between about 1 - 35 molar %, the total of g, h, and i equalling 100 molar %.
25. Method as recited in Claim 24 wherein E comprises acrylic acid residue, R1 comprises 2-hydroxypropylene, and R2 comprises 2,3-dihydroxypropyl.
26. Method as recited in Claim 21 wherein M comprises a member selected from the group consisting of H, Na, K, NH4+, an organic amine group, or an alkyl group having from 1 to 3 carbon atoms.
27. Method as recited in Claim 21 wherein said polymer is added to said aqueous medium in an amount of from about 0.1 - 500 parts polymer based upon 1 million parts of said aqueous medium.
28. Method of inhibiting the corrosion of metal parts in contact with an aqueous medium, said method comprising a) assuring that the pH of said aqueous medium is 5.5 or above b) assuring that the aqueous medium contains a calcium or other appropriate ion concentration selected from the group consisting of zinc, nickel, and chromium and mixtures thereof, and c) adding to said aqueous medium a water soluble polymer, said polymer comprising repeat units characterized by the structure wherein E in the above formula is the residue obtained after polymerization of an .alpha., .beta. ethylenically unsaturated compound, R1 is a hydroxy substituted lower alkyl group having from about 1 - 6 carbon atoms or a non-substituted lower alkyl group having from about 1 - 6 carbon atoms; M is a water soluble cation or hydrogen, and the molar ratio g:h of about 30:1 to 1:20, and also adding to said aqueous medium a water soluble orthophosphate compound.
29. Method as recited in Claim 28 wherein the weight ratio of said polymer to said orthophosphate expressed as PO4-3 is from about 1:6 to about 4:1.
30. A method according to Claim 28 wherein the weight ratio of said polymer to said orthophosphate expressed as PO4---is from about 1:6 to about 2:1.
31. A method according to Claim 28, wherein the orthophosphate (expressed as PO4---) is added to said aqueous medium in an amount of about 6 to 30 parts per million parts of water and said polymer is added in an amount from 3 to 25 parts per million parts of water.
32. A method according to Claim 30, wherein the orthophosphate (expressed as PO4---) is added to said aqueous medium in an amount of about 6 to 30 parts per million parts of water and said polymer is added in an amount from 3 to 25 parts per million parts of water.
33. A method according to claim 32, wherein the pH is maintained or adjusted within the range of 6.5 to 9.5 and said calcium ion concentration is 15 parts per million parts of water or above.
34. A method according to claim 28, wherein a water-soluble organo phosphonic acid compound or its water-soluble salt is added to said aqueous medium.
35. A method according to claim 34, wherein the weight ratio of compounds and polymer are added as follows:
said polymer to said orthophosphate compound expressed as PO4--- is from about 1:6 to about 2:1; and said orthophosphate expressed as PO4--- to said organo phosphonic acid compound expressed as PO4---is from about 2:1 to about 8:1
said polymer to said orthophosphate compound expressed as PO4--- is from about 1:6 to about 2:1; and said orthophosphate expressed as PO4--- to said organo phosphonic acid compound expressed as PO4---is from about 2:1 to about 8:1
36. A method according to claim 35, wherein the compounds and polymer are added to said aqueous medium as follows:
orthophosphate compound expressed as PO4---: 6 to 30 parts per million parts of water;
organo phosphonic acid compound expressed as PO4---:
1 to 6 parts per million parts of water; and polymer: 3 to 25 parts per million parts of water.
orthophosphate compound expressed as PO4---: 6 to 30 parts per million parts of water;
organo phosphonic acid compound expressed as PO4---:
1 to 6 parts per million parts of water; and polymer: 3 to 25 parts per million parts of water.
37. A method according to Claim 35 wherein the pH of the aqueous medium is adjusted or maintained at about 605 to 9.5 and the calcium ion concentration is 15 parts per million parts of water or above.
38. A method according to claim 28, wherein the aqueous medium is contained in a cooling water system.
39. A method as recited in claim 28 wherein E comprises the residue remaining after polymerization of a compound or compounds selected from the group consisting of acrylic acid, acrylamide, maleic acid or anhydride, itaconic acid, methacrylic acid, lower alkyl (C1 - C6) ester or hydroxylated lower alkyl (C1 - C6) ester of said acids.
40. Method as recited in Claim 39 wherein E comprises acrylic acid residue and 2-hydroxypropylacrylate residue.
41. Method as recited in Claim 28 wherein said polymer comprises another repeat unit comprising the structure wherein R2 comprises a hydroxylated lower alkyl (C1 - C6) group and the molar percentage of g in said polymer being between about 40 - 90 molar %, the molar percentage of h being between about 2 - 40 molar % and the molar percentage of i in said polymer being between about 1 - 35 molar %, the total of g, h, and i equalling 100 molar %.
42. Method as recited in Claim 41 wherein E comprises acrylic acid residue, R1 comprises 2-hydroxypropylene and R2 comprises 2,3-dihydroxypropyl.
43. Method as recited in Claim 29 further comprising adding a water soluble polyphosphate compound to said aqueous medium wherein said orthophosphate to polyphosphate (both expressed as PO4-3) is about 25:1 to about 1:1.
44. Method as recited in claim 43 wherein the compounds and the polymer are added to the aqueous medium in the following amounts:
orthophosphate expressed as PO4-3: 6 to 30 parts per million parts of water;
polymer: 3 to 25 parts per million parts of water polyphosphate expressed as PO4-3: 3 to 10 parts per million parts of water.
orthophosphate expressed as PO4-3: 6 to 30 parts per million parts of water;
polymer: 3 to 25 parts per million parts of water polyphosphate expressed as PO4-3: 3 to 10 parts per million parts of water.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/816,173 US4659480A (en) | 1983-10-26 | 1986-01-03 | Water treatment polymers and methods of use thereof |
| US816,173 | 1986-01-03 |
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| Publication Number | Publication Date |
|---|---|
| CA1247292A true CA1247292A (en) | 1988-12-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000525311A Expired CA1247292A (en) | 1986-01-03 | 1986-12-15 | Water treatment polymers and methods of use thereof |
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| CA (1) | CA1247292A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114084969A (en) * | 2021-11-16 | 2022-02-25 | 常州市武进盛源化工有限公司 | Cooling water scale inhibitor and application thereof |
-
1986
- 1986-12-15 CA CA000525311A patent/CA1247292A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114084969A (en) * | 2021-11-16 | 2022-02-25 | 常州市武进盛源化工有限公司 | Cooling water scale inhibitor and application thereof |
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