US3637609A - Preparation of sodium polymaleate - Google Patents
Preparation of sodium polymaleate Download PDFInfo
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- US3637609A US3637609A US42542A US3637609DA US3637609A US 3637609 A US3637609 A US 3637609A US 42542 A US42542 A US 42542A US 3637609D A US3637609D A US 3637609DA US 3637609 A US3637609 A US 3637609A
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- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 title description 14
- 239000011734 sodium Substances 0.000 title description 14
- 229910052708 sodium Inorganic materials 0.000 title description 14
- 238000002360 preparation method Methods 0.000 title description 2
- -1 POLY(MALEIC ACID) Polymers 0.000 abstract description 55
- 229920001444 polymaleic acid Polymers 0.000 abstract description 21
- 150000003839 salts Chemical class 0.000 abstract description 17
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 16
- 239000002002 slurry Substances 0.000 abstract description 15
- 239000003599 detergent Substances 0.000 abstract description 10
- 239000007864 aqueous solution Substances 0.000 abstract description 8
- 229920000141 poly(maleic anhydride) Polymers 0.000 abstract description 7
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 abstract description 6
- 229910001948 sodium oxide Inorganic materials 0.000 abstract description 6
- 238000004061 bleaching Methods 0.000 abstract description 5
- 230000003301 hydrolyzing effect Effects 0.000 abstract description 3
- NOJNFULGOQGBKB-UHFFFAOYSA-M sodium;3-[3-tert-butylsulfanyl-1-[[4-(6-ethoxypyridin-3-yl)phenyl]methyl]-5-[(5-methylpyridin-2-yl)methoxy]indol-2-yl]-2,2-dimethylpropanoate Chemical compound [Na+].C1=NC(OCC)=CC=C1C(C=C1)=CC=C1CN1C2=CC=C(OCC=3N=CC(C)=CC=3)C=C2C(SC(C)(C)C)=C1CC(C)(C)C([O-])=O NOJNFULGOQGBKB-UHFFFAOYSA-M 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 32
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 18
- 239000002253 acid Substances 0.000 description 13
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 12
- 239000000047 product Substances 0.000 description 12
- 238000000034 method Methods 0.000 description 11
- 239000003513 alkali Substances 0.000 description 8
- KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical compound CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 description 6
- 239000000460 chlorine Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- 239000007844 bleaching agent Substances 0.000 description 4
- 239000005708 Sodium hypochlorite Substances 0.000 description 3
- 239000003518 caustics Substances 0.000 description 3
- 239000012153 distilled water Substances 0.000 description 3
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 239000011541 reaction mixture Substances 0.000 description 3
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- YNJSNEKCXVFDKW-UHFFFAOYSA-N 3-(5-amino-1h-indol-3-yl)-2-azaniumylpropanoate Chemical compound C1=C(N)C=C2C(CC(N)C(O)=O)=CNC2=C1 YNJSNEKCXVFDKW-UHFFFAOYSA-N 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 229920000388 Polyphosphate Polymers 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 description 2
- 238000003556 assay Methods 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 238000004737 colorimetric analysis Methods 0.000 description 2
- 238000006114 decarboxylation reaction Methods 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 235000021317 phosphate Nutrition 0.000 description 2
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 2
- 239000001205 polyphosphate Substances 0.000 description 2
- 235000011176 polyphosphates Nutrition 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 159000000000 sodium salts Chemical class 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- VSYMNDBTCKIDLT-UHFFFAOYSA-N [2-(carbamoyloxymethyl)-2-ethylbutyl] carbamate Chemical compound NC(=O)OCC(CC)(CC)COC(N)=O VSYMNDBTCKIDLT-UHFFFAOYSA-N 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 239000012736 aqueous medium Substances 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000000383 hazardous chemical Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 229910000031 sodium sesquicarbonate Inorganic materials 0.000 description 1
- 235000018341 sodium sesquicarbonate Nutrition 0.000 description 1
- 235000019832 sodium triphosphate Nutrition 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000000271 synthetic detergent Substances 0.000 description 1
- UNXRWKVEANCORM-UHFFFAOYSA-I triphosphate(5-) Chemical compound [O-]P([O-])(=O)OP([O-])(=O)OP([O-])([O-])=O UNXRWKVEANCORM-UHFFFAOYSA-I 0.000 description 1
- WCTAGTRAWPDFQO-UHFFFAOYSA-K trisodium;hydrogen carbonate;carbonate Chemical compound [Na+].[Na+].[Na+].OC([O-])=O.[O-]C([O-])=O WCTAGTRAWPDFQO-UHFFFAOYSA-K 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
- C11D3/16—Organic compounds
- C11D3/37—Polymers
- C11D3/3746—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C11D3/3757—(Co)polymerised carboxylic acids, -anhydrides, -esters in solid and liquid compositions
- C11D3/3761—(Co)polymerised carboxylic acids, -anhydrides, -esters in solid and liquid compositions in solid compositions
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F8/00—Chemical modification by after-treatment
Definitions
- the sodium salt of poly(maleic acid), useful as a detergent builder is prepared by hydrolyzing poly(maleic anhydride) with water at 60 to 80 C., and simultaneously adding the aqueous solution and a source of sodium oxide into a heel of water at pH 9.2 to 10.6, maintaining this pH throughout the addition, then bleaching the slurry, and recovering the salt.
- the commonly used detergent compositions include soaps and synthetic detergents, mixed with compounds known as builders, which act both to improve the detergent power of the primary detergents, and to reduce the cost of the over-all compositions.
- the inorganic polyphosphates such as sodium and potassium tripolyphosphate, have been almost universally used as the bulk of the builder constituents in such compositions.
- polyphosphates such as sodium and potassium tripolyphosphate
- Any such detergent builder must, of course, have optimum economics, and should not produce different environmental hazards than do the phosphates.
- Nitrilotriacetic acid which is currently being used commercially as a substitute for phosphates, is both more expensive and potentially dangerous, in that it can keep quantities of heavy metals in solution in water.
- Other available builders are either much more costly, or have other serious drawbacks.
- a potentially interesting group of possible detergent builders comprises the alkali metal salts of poly(carboxylic acid)s as described in Diehl U.S. Pat. 3,308,067, issued Mar. 7, 1967.
- This patent describes the use, as builders, of the Water-soluble salts of poly(c-arboxylic acid)s, the simplest and least expensive of which are the sodium salts of various poly(maleic acid)s.
- the salts of poly(maleic acid) are made by homopolymerizing maleic anhydride, hydrolyzing the poly(maleic anhydride) to poly(maleic acid) in an aqueous medium and neutralizing the acid to form the salt, as described, for example, in Berry U.S. Pat. 3,359,246 of Dec. 19', 1967.
- the neutralization is apparently a simple step, but difficulties are encountered in attempting to prepare a white sodium polymaleate which is acceptable for use in household detergents. -If alkali is added to water solutions of the acid, as described in U.S. Pat. 3,359,246, there is a marked tendency for salt to precipitate in lumps which occlude acid, unless the salt is kept in solution during the addition of alkali by using sufficient water. Since the solubility of sodium polymaleate is of the order of under 1%, the cost of recovery of salt makes such a dilution uneconomic. If the reverse procedure is used, adding the poly(maleic acid) solution to the alkali solution, the salt precipitates nicely as fine yellow particles; but the produc- 3,637,609 Patented Jan. 25, 1972 tion of white material therefrom with bleach is extremely diflicult and expensive.
- the object can be attained by (1) preparing an aqueous solution of poly(maleic acid) at a temperature not in excess of about C.; (2) preparing an aqueous solution of a source of sodium oxide to react with the acid; (3) feeding the two solutions into a heel of water at pH about 9.2 to 10.6 and maintaining the reaction mixture within that pH range and at a temperature not above about 80 C. throughout the addition, to obtain a slurry of salt in a solution thereof; (4) bleaching the slurry while maintaining the pH range; and (5 recovering bleached salt from the reaction mixture.
- maleic anhydride the basic raw material for the process of this invention, is prepared in known manner, as described in Berry U.S. Pat. 3,359,246, or more preferably by the methods described in the Blumbergs et a1.
- the poly(maleic anhydride)s produced will have an average of from at least 3 units per molecule to about 500, with typical molecular weights of the order of about 5,500 to 25,000.
- the first step in the process involves hydrolysis of the poly(maleic anhydride) to poly(maleic acid). This can be done by using water at temperatures near the boiling point for a short period of time, for example 30 minutes at C., as described in U.S. Pat. 3,359,246. We prefer to operate at about 60 to 80 C. for 1 to 2 hours, in order to reduce decarboxylation which we have found occurs at temperatures near the boiling point. Maleic anhydride can be kept at C.
- the solutions of poly(maleic acid) prepared should be sufliciently concentrated to permit economic operation.
- the rather concentrated acid solution is then run into a heel of water at pH about 9.2 to 10.6, at the selected temperature; the pH is maintained through the reaction, and the temperature is kept below 80 C. Simultaneously, an aqueous alkali is added, to maintain the pH within the above limits.
- the amounts of water in the heel and in the alkali are kept minimal for cost reasons; we prefer that the final concentration of salt is at least 10%. At this concentration and at these temperatures, almost all of the salt precipitates, to form an aqueous slurry, in the form of finely divided pale yellow particles.
- sodium hydroxide, sodium carbonate and sodium sesquicarbonate as sodium oxide sources in our work.
- the slurry is then treated with a bleach, such as hydrogen peroxide, peracetic acid, sodium hypochlorite, perbenzoic acid or ozone, and bleached to a whiteness of at least 90% as measured by photoelectric tristimulus colorimetry with a magnesium oxide standard, with a Zeiss Elrepho colorimeter.
- a bleach such as hydrogen peroxide, peracetic acid, sodium hypochlorite, perbenzoic acid or ozone
- the bleach is conducted within the same pH limits as the precipitation, i.e. 9.2 to 10.6. Since the solid salt does not decarboxylate readily, any convenient bleaching temperature may be used.
- the slurry is evaporated to dryness to obtain the desired end product.
- the slurry may be evaporated to dryness at room temperature, or under vacuum, or it can be spray dried if desired.
- the salt must be bleached and not the poly- (maleic acid).
- bleaches 70% hydrogen peroxide, sodium hypochlorite with 5.5% of available chlorine, 40% assay peracetic acid, 33% assay perbenzoic acid in tertbutanol, and ozone
- salts were obtained with the very poor reflectance rtaing of 49 to 62%.
- EXAMPLE 1 One hundred grams of poly(maleic anhydride) obtained by homopolymerization of maleic anhydride in the presence of maleyl-acetyl peroxide and boric acid as described in Blumbergs et al. patent application S.N. 862,059, filed Sept. 29, 1969 were dissolved in 400 ml. of distilled water at 60 to 70 C. and kept at this temperature for 2 hours.
- Sodium hydroxide solution was prepared in another beaker by dissolving 77 g. of NaOH pellets in 180 ml. of distilled water. Both solutions were simultaneously charged into a beaker, equipped with a laboratory stirrer and containing 100 ml. of distilled water, maintaining the pH in the range of 9.2 to 10.6. This was easily achieved by measuring the pH while regulating the flow rates of sodium hydroxide solution and poly(maleic acid) solution.
- the whiteness of this product was measured by the method of photoelectric tristimulus colorimetry, employing the Elrepho instrument, manufactured by Carl Zeiss in Germany. About 5 to g. of the product were made in a tablet, 45 mm. in diameter and 5 mm. thick, with the Elrepho powder press 45. After the tablet was made, it was placed on the measuring aperture and the reflectance value was read, using magnesium oxide tablet as the primary standard. The reflectance value of this sample was 94.2.
- Run A (for comparison) The same as Example 1, only the mode of addition of the solutions was different.
- the poly(maleic acid) solution was charged into the caustic solution with good stirring.
- the pH of the mixture changed from 14 to 11 during the addition time.
- 5 g. of 70% hydrogen peroxide were added and the stirring continued for an additional hour.
- the color of the slurry changed from yellow to pale yellow.
- 158 g. of cream-color solids were obtained.
- the whiteness of the product was 82.
- Run B (for comparison) The same as Example 1, only the mode of addition of the solutions was changed.
- the caustic solution was charged into the poly(maleic acid) solution with good stirring while measuring the pH.
- the product precipitated out as large, gummy and sticky lumps. These lumps did not break down even by increased stirring speed. Up to this point, the pH showed a change from 2.3 to 7.0.
- EXAMPLE 2 The same as Example 1, only the 5 g. of hydrogen peroxide were replaced with 10 g. of sodium hypochlorite solution having 5.5% of available chlorine. The whiteness of the product obtained was 92.8.
- EXAMPLE 3 The same as Example 1, except that the 5 g. of hydrogen peroxide were replaced with 10 g. of 40% commercial peracetic acid. In this case, a small amount of sodium hydroxide solution was required to adjust the pH to 10.0. The whiteness of the product obtained was 93.9.
- Run C (for comparison) The same as Example 1, only the addition of the hydrogen peroxide bleaching agent was omitted and the slurry was evaporated on a Rinco under reduced pressure without bleaching. The whitness of the product obtained was 56. The product was too dark to be used as a detergent builder.
- the method of making white finely divided sodium polymaleate which comprises (a) preparing an aqueous solution of poly(maleic acid) at a temperature not in excess of C.; (b) preparing an aqueous solution of a source of sodium oxide capable of reacting with the poly(maleic acid) to form sodium polymaleate; (c) feeding the two solutions into an aqueous liquor at a pH of 9.2 to 10.6 and maintaining the reaction mixture within that pH range and at a temperature not above 80 C.; (d) precipitating sodium polymaleate in said aqueous liquor to form a slurry; (e) bleaching the precipitated sodium polymaleate in said slurry while maintaining said pH range and (f) recovering bleached sodium polymaleate from the slurry.
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- Chemical Kinetics & Catalysis (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Wood Science & Technology (AREA)
- General Chemical & Material Sciences (AREA)
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- Detergent Compositions (AREA)
Abstract
THE SODIUM SALT OF POLY(MALEIC ACID), USEFUL AS A DETERGENT BUILDER, IS PREPARED BY HYDROLYZING POLY(MALEIC ANHYDRIDE) WITH WATER AT 60 TO 80*C., AND SIMULTANEOUSLY ADDING THE AQUEOUS SOLUTION AND A SOURCE OF SODIUM OXIDE INTO A HEEL OF WATER AT PH 9.2 TO 10.6, MAITAINING THIS PH THROUGHOUT THE ADDITION THEN BLEACHING THE SLURRY, AND RECOVERING THE SALT.
Description
United States Patent Office 3,637,609 PREPARATION OF SODIUM POLYMALEATE John H. Blumbergs, Highland Park, Joseph H. Finley, Metuchen, and John J. Rizzo, Trenton, N.J., assignors to FMC Corporation, New York, N.Y. No Drawing. Filed June 1, 1970, Ser. No. 42,542 Int. Cl. C08f 27/04 U.S. Cl. 26078.4 R Claims ABSTRACT OF THE DISCLOSURE The sodium salt of poly(maleic acid), useful as a detergent builder, is prepared by hydrolyzing poly(maleic anhydride) with water at 60 to 80 C., and simultaneously adding the aqueous solution and a source of sodium oxide into a heel of water at pH 9.2 to 10.6, maintaining this pH throughout the addition, then bleaching the slurry, and recovering the salt.
BACKGROUND OF THE INVENTION The commonly used detergent compositions include soaps and synthetic detergents, mixed with compounds known as builders, which act both to improve the detergent power of the primary detergents, and to reduce the cost of the over-all compositions. The inorganic polyphosphates, such as sodium and potassium tripolyphosphate, have been almost universally used as the bulk of the builder constituents in such compositions. However, there has beena growing resistance to the use of polyphosphates, on the ground that they induce the build-up of undesirable vegetation in waters into which the detergents wastes are eventually discharged, and there 'has been a growing demand for detergent builders which would not cause this difficulty. Any such detergent builder must, of course, have optimum economics, and should not produce different environmental hazards than do the phosphates.
Many such builders have been suggested, but all have substantial disadvantages. Nitrilotriacetic acid, which is currently being used commercially as a substitute for phosphates, is both more expensive and potentially dangerous, in that it can keep quantities of heavy metals in solution in water. Other available builders are either much more costly, or have other serious drawbacks.
A potentially interesting group of possible detergent builders comprises the alkali metal salts of poly(carboxylic acid)s as described in Diehl U.S. Pat. 3,308,067, issued Mar. 7, 1967. This patent describes the use, as builders, of the Water-soluble salts of poly(c-arboxylic acid)s, the simplest and least expensive of which are the sodium salts of various poly(maleic acid)s. The salts of poly(maleic acid) are made by homopolymerizing maleic anhydride, hydrolyzing the poly(maleic anhydride) to poly(maleic acid) in an aqueous medium and neutralizing the acid to form the salt, as described, for example, in Berry U.S. Pat. 3,359,246 of Dec. 19', 1967.
The neutralization is apparently a simple step, but difficulties are encountered in attempting to prepare a white sodium polymaleate which is acceptable for use in household detergents. -If alkali is added to water solutions of the acid, as described in U.S. Pat. 3,359,246, there is a marked tendency for salt to precipitate in lumps which occlude acid, unless the salt is kept in solution during the addition of alkali by using sufficient water. Since the solubility of sodium polymaleate is of the order of under 1%, the cost of recovery of salt makes such a dilution uneconomic. If the reverse procedure is used, adding the poly(maleic acid) solution to the alkali solution, the salt precipitates nicely as fine yellow particles; but the produc- 3,637,609 Patented Jan. 25, 1972 tion of white material therefrom with bleach is extremely diflicult and expensive.
OBJECT OF THIS INVENTION STATEMENT OF THE INVENTION We have found that the object can be attained by (1) preparing an aqueous solution of poly(maleic acid) at a temperature not in excess of about C.; (2) preparing an aqueous solution of a source of sodium oxide to react with the acid; (3) feeding the two solutions into a heel of water at pH about 9.2 to 10.6 and maintaining the reaction mixture within that pH range and at a temperature not above about 80 C. throughout the addition, to obtain a slurry of salt in a solution thereof; (4) bleaching the slurry while maintaining the pH range; and (5 recovering bleached salt from the reaction mixture.
DETAILED DESCRIPTION OF THE INVENTION Poly (maleic anhydride), the basic raw material for the process of this invention, is prepared in known manner, as described in Berry U.S. Pat. 3,359,246, or more preferably by the methods described in the Blumbergs et a1. applications S.N. 758,678, filed Sept. 10, 1968-and S.N. 862,059, filed Sept. 29,1969. The poly(maleic anhydride)s produced will have an average of from at least 3 units per molecule to about 500, with typical molecular weights of the order of about 5,500 to 25,000.
The first step in the process involves hydrolysis of the poly(maleic anhydride) to poly(maleic acid). This can be done by using water at temperatures near the boiling point for a short period of time, for example 30 minutes at C., as described in U.S. Pat. 3,359,246. We prefer to operate at about 60 to 80 C. for 1 to 2 hours, in order to reduce decarboxylation which we have found occurs at temperatures near the boiling point. Maleic anhydride can be kept at C. for an hour in a 21% aqueous solution with a loss of only 0.02 mol percent of CO In contrast, a typical poly(maleic acid) will lose 1.6 mol percent under the same conditions, and a partially neutralized poly(maleic acid) (pH 4.75) will lose 4.3 mol percent of CO At 50 C., the losses are one-third of what they are at 100 C.
The solutions of poly(maleic acid) prepared should be sufliciently concentrated to permit economic operation. We prefer to operate as close to the solubility limit of the acid at the temperatures of operation as is technically feasible. Since solubility increases with temperature, we prefer to operate close to 80 C., this upper limit being selected, as indicated above, to minimize decarboxylation of the product. In this temperature range, about 20% solutions of the acid represent a convenient concentration. We can, of course, operate at much lower concentrations, of the order of a few percent, since the salt has a solubility of under 1% in water; but operations at lower concentrations are, of course, more expensive. Operations at temperatures below 60 C. are feasible, and we have operated to below ambient temperatures; but since the solubility of the poly(maleic acid) drops, we prefer to operate between 60 and 80 C.
The rather concentrated acid solution is then run into a heel of water at pH about 9.2 to 10.6, at the selected temperature; the pH is maintained through the reaction, and the temperature is kept below 80 C. Simultaneously, an aqueous alkali is added, to maintain the pH within the above limits. The amounts of water in the heel and in the alkali are kept minimal for cost reasons; we prefer that the final concentration of salt is at least 10%. At this concentration and at these temperatures, almost all of the salt precipitates, to form an aqueous slurry, in the form of finely divided pale yellow particles. We have used sodium hydroxide, sodium carbonate and sodium sesquicarbonate as sodium oxide sources in our work.
The slurry is then treated with a bleach, such as hydrogen peroxide, peracetic acid, sodium hypochlorite, perbenzoic acid or ozone, and bleached to a whiteness of at least 90% as measured by photoelectric tristimulus colorimetry with a magnesium oxide standard, with a Zeiss Elrepho colorimeter. The bleach is conducted within the same pH limits as the precipitation, i.e. 9.2 to 10.6. Since the solid salt does not decarboxylate readily, any convenient bleaching temperature may be used.
Finally, the slurry is evaporated to dryness to obtain the desired end product. The slurry may be evaporated to dryness at room temperature, or under vacuum, or it can be spray dried if desired.
It should be noted that the sequence of reaction is most important. If the alkali solution is added to the acid solution, gummy, sticky lumps begin to precipitate when the pH reaches about 7.0, when about half the alkali has been added, If the acid is added to the alkali, a fine yellowish precipitate is obtained, which is very difiicult to bleach. Direct comparison on a number of trials gave creamy products with a whiteness of the order of 75 to 85, as against 92 to 95 for products produced from the identical raw materials, concentrations and temperatures using the simultaneous controlled addition technique of this invention.
Moreover, the salt must be bleached and not the poly- (maleic acid). Using a variety of bleaches (70% hydrogen peroxide, sodium hypochlorite with 5.5% of available chlorine, 40% assay peracetic acid, 33% assay perbenzoic acid in tertbutanol, and ozone) on the acid, salts were obtained with the very poor reflectance rtaing of 49 to 62%.
SPECIFIC EXAMPLES OF THE INVENTION The following examples of the invention are given by way of illustration and not by way of limitation.
EXAMPLE 1 One hundred grams of poly(maleic anhydride) obtained by homopolymerization of maleic anhydride in the presence of maleyl-acetyl peroxide and boric acid as described in Blumbergs et al. patent application S.N. 862,059, filed Sept. 29, 1969 were dissolved in 400 ml. of distilled water at 60 to 70 C. and kept at this temperature for 2 hours. Sodium hydroxide solution was prepared in another beaker by dissolving 77 g. of NaOH pellets in 180 ml. of distilled water. Both solutions were simultaneously charged into a beaker, equipped with a laboratory stirrer and containing 100 ml. of distilled water, maintaining the pH in the range of 9.2 to 10.6. This was easily achieved by measuring the pH while regulating the flow rates of sodium hydroxide solution and poly(maleic acid) solution.
After all the solutions were charged into the beaker, 5 g. of 70% hydrogen peroxide were added and the stirring continued for an additional hour at 60 to 80 C. The slurry changed from pale yellow to white during this time. Then the slurry was evaporated and the solids were dried under reduced pressure. There were obtained 160 g. of white sodium polymaleate product.
The whiteness of this product was measured by the method of photoelectric tristimulus colorimetry, employing the Elrepho instrument, manufactured by Carl Zeiss in Germany. About 5 to g. of the product were made in a tablet, 45 mm. in diameter and 5 mm. thick, with the Elrepho powder press 45. After the tablet was made, it was placed on the measuring aperture and the reflectance value was read, using magnesium oxide tablet as the primary standard. The reflectance value of this sample was 94.2.
Run A (for comparison) The same as Example 1, only the mode of addition of the solutions was different. In this case, the poly(maleic acid) solution was charged into the caustic solution with good stirring. The pH of the mixture changed from 14 to 11 during the addition time. After all of the poly(maleic acid) solution was added, 5 g. of 70% hydrogen peroxide were added and the stirring continued for an additional hour. The color of the slurry changed from yellow to pale yellow. After evaporation under reduced pressure, 158 g. of cream-color solids were obtained. The whiteness of the product was 82.
Run B (for comparison) The same as Example 1, only the mode of addition of the solutions was changed. In this case, the caustic solution was charged into the poly(maleic acid) solution with good stirring while measuring the pH. After about a half of the caustic solution was consumed, the product precipitated out as large, gummy and sticky lumps. These lumps did not break down even by increased stirring speed. Up to this point, the pH showed a change from 2.3 to 7.0.
Also by adding additional sodium hydroxide solution, the lumps did not break down, but, on the contrary, increased in size. The product lumps were collected and analyzed and were found to be a mixture of sodium polymaleate and poly(maleic acid). No pure sodium polymaleate product was obtained by this procedure.
EXAMPLE 2 The same as Example 1, only the 5 g. of hydrogen peroxide were replaced with 10 g. of sodium hypochlorite solution having 5.5% of available chlorine. The whiteness of the product obtained was 92.8.
EXAMPLE 3 The same as Example 1, except that the 5 g. of hydrogen peroxide were replaced with 10 g. of 40% commercial peracetic acid. In this case, a small amount of sodium hydroxide solution was required to adjust the pH to 10.0. The whiteness of the product obtained was 93.9.
Run C (for comparison) The same as Example 1, only the addition of the hydrogen peroxide bleaching agent was omitted and the slurry was evaporated on a Rinco under reduced pressure without bleaching. The whitness of the product obtained was 56. The product was too dark to be used as a detergent builder.
Obviously, the examples can be multiplied indefinitely without departing from the spirit of the invention as defined in the claims.
Pursuant to the requirements of the patent statutes, the principle of this invention has been explained and exemplified in a manner so that it can be readily practiced by those skilled in the art, such exemplification including what is considered to represent the best embodiment of the invention. However, it should be clearly understood that, within the scope of the appended claims, the invention may be practiced by those skilled in the art, and having the benefit of this disclosure, otherwise than as specifically described and exemplified herein.
What is claimed is:
1. The method of making white finely divided sodium polymaleate which comprises (a) preparing an aqueous solution of poly(maleic acid) at a temperature not in excess of C.; (b) preparing an aqueous solution of a source of sodium oxide capable of reacting with the poly(maleic acid) to form sodium polymaleate; (c) feeding the two solutions into an aqueous liquor at a pH of 9.2 to 10.6 and maintaining the reaction mixture within that pH range and at a temperature not above 80 C.; (d) precipitating sodium polymaleate in said aqueous liquor to form a slurry; (e) bleaching the precipitated sodium polymaleate in said slurry while maintaining said pH range and (f) recovering bleached sodium polymaleate from the slurry.
2. The method of claim 1 in which the acid solution is near saturation at the temperature employed.
3. The method of claim 1 in which the temperature during acid solution and precipitation is kept between 60 and 80 C.
4. Process of claim 1 wherein said aqueous solution of poly(maleic acid) and the sodium oxide solutions are added continuously to said aqueous liquor, a portion of said slurry is continuously removed and bleached while maintaining its pH range of 9.2 to 10.6, and bleached sodium polymaleate is continuously recovered from its aqueous mother liquor.
5. Process of claim 1 wherein said aqueous liquor is a heel of water.
References Cited UNITED STATES PATENTS JOSEPH L. SCHOFER, Primary Examiner I. KIGHT, Assistant Examiner US. Cl. X.R. 252152
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US4254270A | 1970-06-01 | 1970-06-01 |
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US3637609A true US3637609A (en) | 1972-01-25 |
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Application Number | Title | Priority Date | Filing Date |
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US42542A Expired - Lifetime US3637609A (en) | 1970-06-01 | 1970-06-01 | Preparation of sodium polymaleate |
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Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4182807A (en) * | 1977-04-25 | 1980-01-08 | Solvay & Cie. | Process for the manufacture of salts of hydroxycarboxylated polymers of reduced molecular weight |
US4182806A (en) * | 1977-04-25 | 1980-01-08 | Solvay & Cie. | Process for the manufacture of salts of poly-alpha-hydroxyacrylic acids |
US4668735A (en) * | 1982-10-06 | 1987-05-26 | Kao Corporation | Process for producing polymaleate |
US4797223A (en) * | 1988-01-11 | 1989-01-10 | Rohm And Haas Company | Water soluble polymers for detergent compositions |
US4818794A (en) * | 1986-09-19 | 1989-04-04 | Basf Aktiengesellschaft | Slightly crosslinked, water-soluble polymaleic acid, its preparation and its use |
EP0404377A1 (en) * | 1989-06-06 | 1990-12-27 | Ausidet S.R.L. | Water soluble copolymers of maleic anhydride |
US5126069A (en) * | 1989-10-13 | 1992-06-30 | Basf Aktiengesellschaft | Water-soluble or -dispersible, oxidized polymer detergent additives |
-
1970
- 1970-06-01 US US42542A patent/US3637609A/en not_active Expired - Lifetime
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4182807A (en) * | 1977-04-25 | 1980-01-08 | Solvay & Cie. | Process for the manufacture of salts of hydroxycarboxylated polymers of reduced molecular weight |
US4182806A (en) * | 1977-04-25 | 1980-01-08 | Solvay & Cie. | Process for the manufacture of salts of poly-alpha-hydroxyacrylic acids |
US4668735A (en) * | 1982-10-06 | 1987-05-26 | Kao Corporation | Process for producing polymaleate |
US4818794A (en) * | 1986-09-19 | 1989-04-04 | Basf Aktiengesellschaft | Slightly crosslinked, water-soluble polymaleic acid, its preparation and its use |
US4886859A (en) * | 1986-09-19 | 1989-12-12 | Basf Aktiengesellschaft | Slightly crosslinked, water-soluble polymaleic acid, its preparation and its use |
US4797223A (en) * | 1988-01-11 | 1989-01-10 | Rohm And Haas Company | Water soluble polymers for detergent compositions |
EP0404377A1 (en) * | 1989-06-06 | 1990-12-27 | Ausidet S.R.L. | Water soluble copolymers of maleic anhydride |
US5126069A (en) * | 1989-10-13 | 1992-06-30 | Basf Aktiengesellschaft | Water-soluble or -dispersible, oxidized polymer detergent additives |
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