Terpolymers of maleic anhydride, scale prevention

[Detailed Description of the Invention]

This invention relates to the scale formation prevention method which uses the hydrolyzed type of the 3 yuan copolymer of a maleic anhydride. Rapid shortage of drinking water is considered for sea water to be solution to a problem, an intermediary cage, and it all over the world. However, it is interfered by the technical problem which Attribution changing this into fresh water with various desalting methods in the character of the mineral salt contained in salt water. These have the low solubility over water, and these precipitation may check the used mechanism or method of a specific desalting method, and has the blockade of the semipermeable membrane of the dialyzing method, and the fall of heat movement of the distilling method as an example of such influence. Whether this lowering desalination efficiency, stopping a desalting method ultimately, and purifying a device and the operation aggravation which must be exchanged are caused. These salt precipitation is usually known as scale (scale), and the foundation has set the chemicals medicine with which scale control research controls scale deposition, and usual to use of a polymer. But among these, a certain thing contained the surface-active agent. The common use feature of almost all the control agent is that the ratio of a medicine versus mineral salt required to control precipitation and delay it is very low. Therefore, it is suggested that it is not what depends this control effect on complex-ization in the crystal growing point which does not allow ON intermediary Core nucleus to come near, and is depended on chelation of the inorganic cation of salt. The most ordinary polymer chosen as using as a scale control agent is a copolymer with a monomer like polymethacrylic acid, polyacrylic acid, poly maleic acid and these acryl amide, or acetic acid vinyl. Anhydrous poly maleic acid which was developed more recently and which was hydrolyzed as an example of a scale control copolymer (U.S. Pat. No. 3810832), Maleic anhydride-acetic acid vinyl copolymer (U.S. Pat. No. 3715307), A maleic anhydride and a mono-ethylene system unsaturated monomer, or the hydrolysis copolymer of the mixture (British patent No. 1414918), A maleic anhydride copolymer and a 3 yuan copolymer (Netherlands patent application O.I.N.7506874), An acrylic acid polymer (U.S. Pat. No. 3514375), a methacrylic acid polymer (U.S. Pat. No. 3444054), A maleic acid copolymer (U.S. Pat. No. 3617577), a styrene maleic anhydride copolymer (U.S. Pat. No. 3289734), polyacrylic acid (U.S. Pat. No. 3293152), etc. are mentioned. If the molar ratio of a monomer portion besides the maleic anhydride partial pair in the copolymer composed in this way when the scale control activity indicated with the character of a polymer and the prior art reference hung up upwards was compared, or a 3 yuan copolymer is lowered, it will be suggested that both charge density and scale control activity fall. For example, To the polymer of the British patent No. 1414918 A set of activities to which activity [ as opposed to calcium carbonate precipitation in the indicated scale control data ] related from the maleic anhydride single polymer to maleic anhydride-acetic acid vinyl ethyl acrylate copolymer of 3 yuan through the maleic anhydride-acrylamide copolymer Falling is shown as it progresses. The same tendency is clear from the correlation of the scale control activity of the polymer of Netherlands patent Suspended application No. 7506874. the application -- therefore, if the ratio of a monomer portion besides a maleic anhydride partial pair in the manufactured examination polymer is made low, the activity to calcium carbonate precipitation will fall. Thus, if literature manufactures the polymer of mixed composition by using a non-carboxylic monomer in combination with a maleic anhydride monomer, it will teach that the scale control activity of the polymer may fall compared with the hydrolyzed poly maleic anhydride. The method used for most polymers manufacturing a scale control polymer so that that may be right is used, and affects the character and activity regardless of the relative ratio of a monomer. The general approach which manufactures a scale control polymer is indicated in U.S. Pat. No. 3755264 and U.S. Pat. No. 3359246 in addition to the method included in the patent which has indicated the use in the top. Although information abundant about how this prior art reference actually manufactures a maleic anhydride and/or an acrylic acid polymer is provided, These manufacturing methods often cause the size of gelling of the polymer under an uncontrollable rate of polymerization, the Trommsdorff (Tromsdorff) effect, and polymerization, gum-izing, and a polymer molecular weight, the loss of control of the range, impractical long polymerization time, and the non-safety of a reaction. Monomer composition by the present invention when the manufacturing method and the active suggestion by a prior art are taken into consideration, It is surprising for having found out the new granular maleic anhydride copolymer of 3 yuan which has the molecular weight range by which the interaction of temperature and a reaction solvent was controlled, and has the scale control activity near it of the poly maleic anhydride hydrolyzed although the content of the maleic anhydride was also low. According to the present invention, it is a structural formula.<img file="JPS6133640B2_D0001.tif" />[Inside R of a formula [Formula]

(CH₃)₂CHCH₂COCH₂- or [Formula]

Come out, it is and; end group Z is a formula (1). of unsaturated (meta) acryl amide, the Maleyl machine of a formula (2) [Formula]

[Formula]

Or it is hydrogen, S is 1-Al Ken of styrene, alpha-methylstyrene, or carbon number 4~10, and it is;R.₁Is H or CH₃It comes out, and it is and;a, b, and c exist by the ratio of a/b/c/d=25-55/25-50/5-15/5-15. The scale formation prevention method at the time of heating or desalting this water is provided by mixing the alkaline metal of the 3 yuan copolymer denoted by ], or the 3 yuan copolymer, amine, and ammonium salt at the concentration of at least 2 ppm in the water containing scale formation impurities. The 3 yuan copolymer whose third monomer (inside S of the above-mentioned formula) is styrene is preferred. This is because scale control activity and hydrolysis type hydrophobicity are balanced preferably. In b+c, 30~50 and a+c are [ 40~55 and d of the desirable monomer ratio of this 3 yuan copolymer ] 5~15. b+c of especially a desirable thing is a molar ratio whose 45~49 and d 41~45 and a+c are 9~13. The method of the present invention is useful as prevention from scale formation at the time of heating or desalting the water containing scale formation impurities like sea water, boiler water, calcium, magnesium positive ion content water, and the impure water same in addition to this. The 3 yuan copolymer used for the method of the present invention is generated by contacting 30~55-mol% of a maleic anhydride, and 30~65-mol% of acryl amide, or methacrylamide in a suitable reaction medium, and also making it hydrolyze. A mixture is heated to a suitable temperature, an uncombined radical initiator, and% of the 5~15-mol third monomer mentioned above are respectively dissolved in a reaction solvent, and it adds at speed which completes addition in 15~180 minutes preferably to a reaction mixture. The usual addition time is about 30~60 minutes. A reaction is preferably performed in an inactive atmosphere, for example, nitrogen. The scrambling of a reaction mixture maintains with every [ the inside of a reaction process ] by churning, blowing in, etc. preferably. All of the employable standard art known for this field can attain isolation of a weight object. There is the usual method by slurry-ization of concentration of the reaction solvent by evaporation, a fault, and the fault solid by the cold water for dissolving an unreacted monomer succeedingly. Thereby, the polymer which does not contain an unreacted monomer substantially is obtained. It includes washing the reaction substance passed as other methods with an organic solvent like ether, a tetrahydro franc, chloroform, a carbon tetrachloride, the same non-polarity, and non-hydroxy Based organic solvent. Subsequently, a polymer can be used now for a scale control use by hydrolyzing by flowing-back underwater. The method of converting an insoluble polymer into the polymer into which solubility was hydrolyzed is required for 6~10 hours. Or a polymer can be hydrolyzed by agitating with about 0.1~4-mol sodium hydroxide solution at the temperature of the range of 25~100 degreeC. Hydrolysis type alkaline metal amine of the 3 yuan copolymer of a maleic anhydride and ammonium salt are generable by using a base for adding an alkali-metal-salt machine, ammonia, or organic amine in above-mentioned hydrolysis type solution, or hydrolyzing the copolymer unhydrolyzed [ of 3 yuan ] directly. Subsequently, although desired 3 yuan copolymer salt can be isolated by evaporating water, it may use directly as solution, without isolating this. Sodium hydroxide, a potassium hydrate, and lithium hydroxide are mentioned to the alkali-metal-salt machine often used. As the ammonium salt machine often used and amine, Monod who has 1~5 carbon atoms, G, trialkylamine, pyridine, morpholine, and Lutidine are mentioned to ammonium hydroxide, ammonia, and each Alkyl machine. The 3 yuan copolymer into which the solid state was hydrolyzed, or its salt can carry out addition directly so that it may become water containing scale formation impurities with the underwater concentration of at least 2 ppm. Or the hydrolyzed 3 yuan copolymer or its salt may be added using the concentration solution in the water which contains scale formation impurities so that it may become the underwater concentration of at least 2 ppm. This processing is performed as understood by the person skilled in the art by the method used for water disposal, and the arbitrary methods of making compatible. For example, when time part type desalination operation is used, the scale control agent of the present invention is added by a time quantity. when continuation type desalination operation is used on the other hand, even if it adds a scale control agent continuously for the re-circulation pipe system of the water containing scale formation impurities -- the maintenance tub of continuation desalination -- it may add to intermediary Source. The scale control in a boiler use can also be attained by the same method. In order to remove the concentration impurities suspended by the control agent in A pot or a boiler so that I may be easily understood by the person skilled in the art, operation must be interrupted occasionally. However, this pure operation is not required difficult cleaning operation, when it is usually performed by A pot, easy drainage of a boiler, or flash washing and removes a scale sediment. It determined by measuring the quantity of the precipitation formed when the standard solution of the synthetic sea water which carries out addition content of the copolymer scale depressant of 3 yuan for the hydrolyzed scale depressant activity of a 3 yuan copolymer which is used by the method of the present invention was heated under pressurization. The method and the result were shown in Example 7, and it decided for the thing for which these did not use two kinds of contrast for, and one did not use a depressant, and another side to compare with what used poly maleic acid (it manufactures by the method given by the British patent No. 1414918). Although the electric charge short density of the hydrolyzed 3 yuan copolymer which these results use by the method of the present invention is falling as compared with it of poly maleic acid and the hydrophobicity is increasing, It is shown that the hydrolyzed 3 yuan copolymer which is used by the method of the present invention has remarkable scale control activity almost equal to it of poly maleic acid. The hydrolyzed 3 yuan copolymer which is used by the method of the present invention, It controls that a crystal [ in / in combination with the 3 yuan copolymer and crystal-nucleus growing point which were hydrolyzed / the point ] further grows, Taking effect according to the marginal mechanism containing the inorganic ion which the hydrophobicity of the third monomer (S in the above-mentioned formula) contained in boundary the copolymer of 3 yuan dissolved of the scale formation of not allowing an ON intermediary come polarity water cage to come near is guessed. The following reference examples 1~7 only illustrate the present invention, and do not limit a claim. (Method A is a comparative example.) Especially all temperature is ambient air temperature, unless it specifies by Centigrade. The infrared spectrum was obtained with the Perkin-Elmer (Perkin-Elmer) IR-21-step type spectrum photometer, and was listed per micron. By using the solution which dissolved a 0.5-g polymer into 100 ml of dimethyl sulfoxide by 25 ±0.01-degreeC, the viscosity measurement used for measuring the molecular weight of a polymer is a standard method using the Ubbelohde (Ubbelohde) viscosity meter, and is It was done. The measured viscosity is relative viscosity (nu) and this is defined as nu=t/to [however, inside t of a formula is the flow time (second) of polymer solution, and to is the flow time (second) of a solvent]. Method A The maleic anhydride manufactured by the method of the British patent No. 1414918, and the copolymer (A) of acryl amide It agitated and heated the solution which consists of a 46.5 g (0.474-mol and 71.4-mol %) maleic anhydride and toluene (13.5g (0.190-mol and 28.6-mol %) and 143.0g) until it reached temperature of 70 degreein nitrogen atmosphere C. Subsequently, 12.0 g (20wt%) of benzoyl peroxide was dissolved in 70 g of toluene, and this solution took solution for 5 minutes, and it added in it. Subsequently, solution was flowed back by 110~113 degreeC for 6 hours. Toluene solution was removed from the resin-like substance by the Decantation method after cooling, and it refined by grinding this substance with benzene. Copolymer A which has relative temperature 1.04 by this was obtained by yield 63%. Composition of copolymer A determined with the CHN analysis method 58.4-mol % Maleic anhydride 41.7-mol % Acryl amide reference example 1 It is 150.0g (1.53 mol) to the 4-poem 2000-ml round bottom flask provided with the 3 yuan copolymer (1) reflux condenser and mechanical stirrer of a maleic anhydride, acryl amide, and styrene. 45-mol% of a maleic anhydride, 108.8 g (1.53-mol and 45-mol %) of acryl amide, 235.0 g of methyl isobutyl ketone, and 235.0 g of xylene were added. Nitrogen was blown into this system and it put in Oil bath which held the flask to 150 degreeC. Solution generated as the reaction mixture was warmed. When flowing back [ Mitigation ] was attained at the reaction mixture temperature of 126~130 degreeC, the uncombined radical initiator solution which consists of 14.71 g of peroxidation G t-butyl, 16.0 g of methyl isobutyl ketone, and 16.0 g of xylene was continuously added at speed which addition completes in 30 minutes. The solution of the third monomer that consists of 35.4 g (0.340-mol and 10-mol %) of styrene, 29.0 g of methyl isobutyl ketone, and 29.0 g of xylene simultaneously was continuously added at speed which addition completes in 60 minutes. The polymer precipitated as fluid reaction slurry under the third monomer addition and after that. After the polymerization was completed substantially, the reaction mixture was cooled and passed to room temperature 2 hours afterward, precipitation was washed by diethylether and vacuum oven drying was carried out by 80 degreeC for 17 hours. Or vacuum oven drying of the precipitation may be washed and carried out. The generated smooth brown powder copolymer of 3 yuan was obtained by yield of 87.6%, and had the relative viscosity of 1.04. Composition of 3 yuan copolymer 1 determined with the CHN analysis method 43-mol % Maleic anhydride 46-mol % Acryl amide 11-mol % Styrene IR (KBr) 2.94, 3.02, 5.42, 5.64, 5.80, 5.86, 6.05, 6.22, and 8.40. Reference example 2 the method of 3 yuan copolymer (2) reference example 1 of a maleic anhydride, acryl amide, and styrene -- therefore, the 1-mol% of monomers -- copolymer 2 of 3 yuan was manufactured by replacing the solvent ratio of reference example 1 with 75wt% methyl isobutyl ketone and 25-% of the weight xylene, using a ratio. Smooth powder copolymer 2 of 3 yuan which has the relative viscosity of 1.04 was obtained by yield of 87.5%. Composition of 3 yuan copolymer 2 determined with the CHN analysis method 43-mol % Maleic anhydride 47-mol % Acryl amide 10-mol % Styrene The IR spectrum (KBr) was in agreement with the thing of copolymer 1 for 3 yuan. Reference example 3 the method of 3 yuan copolymer (3) reference example 1 of a maleic anhydride, acryl amide, and styrene -- therefore, copolymer 3 of 3 yuan was manufactured by replacing the monomer molar ratio of reference example 1 with a 55 mol % maleic anhydride, 35 mol % acryl amide, and 10 mol % styrene. granular 3 yuan copolymer 3 which the relative viscosity of 1.04 has and which was boiled smoothly and carried out was obtained by yield of 88.1%. Composition % of 50.98 mol of 3 yuan copolymer 3 determined with the CHN analysis method 35.5 mol of maleic anhydride % Acryl amide 13.4-mol % Styrene It is the same as that of the thing of 3 yuan copolymer 1, and an IR spectrum (KBr) is Oh. Reference example 4 the method of 3 yuan copolymer (4) reference example 1 of a maleic anhydride, acryl amide, and styrene -- therefore, copolymer 4 of 3 yuan was manufactured by replacing by dicumyl peroxide on the Mol [ butyl / peroxidation G t-] standard, using the same monomer molar ratio. 1.03₉The granular 3 yuan copolymer which has Relative viscosity was obtained by yield of 88.2%. Composition of 3 yuan copolymer 4 determined with the CHN analysis method 44.5-mol % Maleic anhydride 44.6-mol % Acryl amide 10.9-mol % Styrene The IR spectrum (KBr) was in agreement with it of copolymer 1 for 3 yuan. Reference example 5 It is 183.4g (1.871 mol) to the 3 yuan copolymer (5) flask of a maleic anhydride, acryl amide, and 1-Octene. 55-mol% of a maleic anhydride, 72.5 g (1.021-mol and 30-mol %) of acryl amide, 215.0 g of methyl isobutyl ketone, and 215.0 g of xylene were added. Nitrogen was blown into the system for 1.5 hours, and it put into Oil bath subsequently to 150 degreeC held. When flowing back [ Mitigation ] was attained at the reaction mixture temperature of 126~130 degreeC, the solution which consists of 31.3-g peroxidation Dicumel, 36.0 g of methyl isobutyl ketone, and 36.0 g of xylene was required for 1 hour, and was dropped. The solution which consists of 57.3 g (0.51-mol and 15-mol %) 1-Octene, 47.0 g of methyl isobutyl ketone, and 47.0 g of xylene simultaneously was required for 0.5 hour, and was dropped. After the polymerization was completed substantially, the reaction thing was cooled 4 hours afterward. The copolymer was Take(ed) granular 3 yuan, and it washed by superfluous diethylether, and carried out vacuum oven drying by about 90 degreeC. 1.04₀Smooth brown powder copolymer 5 of 3 yuan which has Relative viscosity was obtained by yield of 56%. Composition of 3 yuan copolymer 5 determined with the CHN analysis method 50.9-mol % Maleic anhydride 41.2-mol % Acryl amide 7.85 mol % 1-Octene It is the same as that of it of 3 yuan copolymer 1, and an IR spectrum (KBr) is Oh. Reference example 6 following the method of 3 yuan copolymer (6) reference example 1 of a maleic anhydride, methacrylamide, and styrene -- the 1-mol % -- methacrylamide was used instead of acryl amide by the ratio, and copolymer 6 of 3 yuan was manufactured. 1.05₃Granular 3 yuan copolymer 6 which has Relative viscosity was obtained by yield 95%. Composition of the 3 yuan copolymer determined with the CHN analysis method 42.8-mol % Maleic anhydride 46.7-mol % Methacrylamide 10.3-mol % Styrene Reference example 7 following the method of 3 yuan copolymer (7) reference example 1 of a maleic anhydride, acryl amide, and alpha-methylstyrene -- the 1-mol % -- alpha-methylstyrene was used instead of styrene by the ratio, and copolymer 7 of 3 yuan was manufactured. 1.04₆Granular 3 yuan copolymer 7 which has Relative viscosity was obtained by yield 89.4%. Composition of 3 yuan copolymer 7 determined with the CHN analysis method 44.5-mol % Maleic anhydride 44.9-mol % Acryl amide 10.9-mol % Alpha-methylstyrene example 1 Artificial sea water was manufactured by dissolving the mineral salt of the weight of the hydrolyzed type scale suppressor effect following of the polymer of reference example 1~7 in the distilled water of 1. NaCl 26.5g, MgCl₂2.4 g, MgSO₄3.3 g, CaCl₂1.1 g, KCl 0.72g, NaHCO₃0.245g and NaBr0.08g. In order to examine, they are 166-ml artificial sea water and 6.45 cm about the 1.0-ml aliquot of hydrolysis type (that which heated the 3 yuan copolymer of the reference example underwater for a short time and to which it hydrolyzed the maleic anhydride unit) 0.1% solution of each polymer.²It added to the beaker containing the monel metal foil of (a 1-inch square). 1.0 ml of 0.1% solution of this examination beaker, 166 ml of sea water, and poly maleic acid (the method of the British patent No. 1414918 therefore manufacture), and 6.45 cm²The positive contrast beaker containing the monel metal foil of (a 1-inch square) was put in in the autoclave (pressurized container) containing the 10% chlorination lithium solution which can be agitated. It is 0.703kg/cm about the pressure open valve of autoclave.²Fixed to (10 psi), it is made for the boiling point of a sea water sample to go up to 115degreeC, and autoclave was closed, and it heated until vapor began to have escaped from an open valve (20~30 minutes). Autoclave was cooled after continuing heating for 45 minutes. The internal pressure of autoclave was reduced to atmospheric pressure, contrast and a sample beaker were taken out, and it cooled by bathing of 25 degreeC. Each beaker was analyzed separately as follows. Monel metal foil was removed and all the scales formed by washing by 50-ml 6NHCl were removed. The last volume of sea water was measured and the quantity which evaporated was calculated. Sea water was passed with the 0.2micro cellulose system membrane filter, generation precipitation was collected, and precipitation was slowly washed for the acid used in order to wash monel metal foil through the filter. Subsequently, the quantity of the calcium and/or the magnesium compound which measured the volume of acid solution and precipitated was measured by EDTA titration of the aliquot of acid cleaning liquid. 4 times of test samples and 4 times of positive control samples were examined in all, and an average and standard deviation were calculated. The amount of losses of water was also equalized and standard deviation was obtained. This was computed as % of the whole quantity and expressed as a % evaporation rate. It compared with the table of the scale deposition pair % evaporation rate in the case of the poly maleic acid which has the same type and source as the 3rd table that includes the average of positive contrast, and its % evaporation rate herein. This comparison was used in order to guarantee that abnormalities did not arise during the examination. The average result of the scale control examination using the various reference example polymers of each was combined with the result of having examined and obtained zero contrast (examination which did not use a scale control polymer), and was recorded all over the 2nd table as a millimeter equivalent amount (meq) of EDTA, and the calcium/magnesium complex-ized. % evaporation rate of the 1st table was recorded combining the average scale result. It is required in confirming what kind of influence an amount of evaporation has to scale deposition first in order to compare the scale control activity of an examination polymer with it of positive contrast and poly maleic acid, and Oh. It is assumed that the positive standard for comparison is poly maleic acid, and % evaporation rate is not mainly a function by the difference between Then and a scale control agent with a device and the function of a test condition, It is It was done about such a determination by repeating and examining poly maleic acid as a scale control agent by the experimental condition mentioned above. The amount of scale deposition of each examination which enters in the increase part in a 0.6% evaporation rate respectively on the basis of an evaporation rate 12% was equalized, and the average deviation of each average was computed. These averages, and these each ranges of evaporation were shown in the 2nd table. The performance as a hydrolysis type scale control agent of a reference example polymer can be measured with the performance of poly maleic acid using the data of the 2nd table. After choosing a part for the increase in a range of % evaporation rate from the 2nd table containing taken-up hydrolysis type % evaporation rate of one reference example polymer, the average scale for this increase in a range is compared with the sample average scale of the hydrolysis type of that taken-up reference example polymer from the 1st table from the 2nd table. If the hydrolysis type "sample average scale (Sample Auerage Scale)" value of a reference example polymer is lower than the average scale value of corresponding poly maleic acid, the hydrolyzed type of a reference example polymer will be an existing scale control agent more active than poly maleic acid. When considering this comparison, in order to carry out the comparison judging of the advantage as a hydrolysis type scale control agent of a reference example polymer with the advantage of the poly maleic acid which is positive contrast, a spread of a sample average scale value and poly maleic acid scale value both must be taken into consideration.

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