CS204262B1 - Method of preparing complex compounds of polyamides and polyamidamines for precipitation of lignine compounds from aqueous solutions - Google Patents

Description

The invention relates to a process for the preparation of complex polyamines and polyamidamines by reaction of these compounds, respectively. modified forms thereof, with salts of aluminum or iron (Fe and Fe ^{11 Ni)} for the purpose of precipitation of lignin compounds from aqueous solutions.

Chemical processing of water-soluble lignin compounds is one of the possibilities of complex wood processing in pulp production. This is associated with the problem of developing a suitable procedure for their isolation from aqueous solutions; The simplest way of performing this isolation is to precipitate lignin compounds dissolved in water with suitable substances.

In the available literature, some processes using precondensates of compounds with active hydrogen atom bonded to nitrogen and aldehyde to precipitate lignosulfonic acids are known. Lignosulfonic acid precipitates sulfite waste liquors using precondensates prepared by condensation of aldehydes and compounds of formula wherein X represents O or S or NH, R is H and R ₂ is H or NH ₂ or CN, or also X together with R and R ₂ represents the radical an amino-substituted triazine cycle. Also known are processes using polyethyleneimine, cyanuric chloride or compounds with isocyanate groups in the alkaline and hot (80 ° C) to precipitate lignin products from unused liquid from the production of vanillin. It is known that polyethyleneimine, resp. polyamines, mixed with lignosulfonates, is used to reduce kaolin wastewater pollution.

Verification of the above processes has shown that precipitation of the precondensate prepared directly in the sulphite liquor is uneconomical, condensation carried out separately in an alkaline medium with evaporation of water does not give good results with dilute lignosulfonic acids and is difficult to prepare precondensates. Polyethyleneimine, respectively. polyamines, do not normally precipitate lignosulfonates from aqueous solutions. Heating is uneconomical and practically impracticable for dilute waste water solutions.

The process for the preparation of complex polyamine and polyamidamine compounds for the precipitation of lignin compounds from the aqueous solutions according to the invention consists in the reaction of polyethyleneimines of the general formula

IN - CH3 --C - NH - (CH3 --C - NH) - KI ^{2 12} I n

R 2 R h R wherein R ₃ and R ₄ denote hydrogen or alkyl groups having 1 to 3 carbons, n is 2 to 5.10 ³ , R j denotes hydrogen or

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“Re Rm R * Rg nj = 0 to 1.10 ³ , where R ₅ denotes a bifunctional cross-linking radical

-C — A — C — NH-B — NH-C — A -

Η II N oo o or hydrogen, where A denotes bifunctional radicals aliphatic - (CH ₂ ) _k -, k = 1 to 10, -CH = CH-, O-, m-, ρ-phthaloyl and B denotes - [(CH ₂ ) _{X -} NH] _m - (CH ₂ ) _X - wherein m = 0-3, x = _2a R ₂ denotes hydrogen, R 1 or

R »Rft

H - (- (CH.) - NH - C - CH 2 - N 1 II

-R _e R * R, H where n ₂ = 0 to 1.10 ³ and R ₆ denote hydrogen, R ₅ or cross-linking bi- and multifunctional radicals from compounds such as epichlorohydrin, polyacrylamide derivatives, polyepoxides, dichlorobutene, dichlorobutane, dichlorethylene, dichlorohydrin or derivatives of diisocyanates and all compounds formed from urea, thiourea, guanidine or semicarbazide, thiosemicarbazide, dicyandiamide, melamine and their derivatives or mixtures thereof and lower aliphatic aldehydes of 1 to 4 carbons or dialdehydes of 2 to 4 carbons or fural and its derivatives, , and forming up to 50% aqueous solutions, with 10 ³ to 1 equivalents of Al contained in water-soluble salts at normal room temperature in an aqueous medium containing 10 ^-5 to 50% preferably 0.1 to 1% by weight of the above polyethyleneimines and pH 3 to 7.

In these reactions, the free electron pair on nitrogen connects to the coordination metal of the parent metal (Al, Fe) to form chelate complex compounds, which in the case of said polyelectrolytes are spatially arranged to form spatially cross-linked macromolecules! substances at higher concentrations up to gel-like structures (usually above 10% polyelectrolyte concentration) ·

The highly cationic polyelectrolytes thus prepared are generally used in concentrations of 0.1 to 1% by weight to precipitate lignin compounds, preferably lignosulfonic acids, from aqueous solutions. The precipitation of lignin compounds from aqueous solutions can be carried out over a wide pH range (1-12) and is also effective for solutions having a concentration of about 1 kg.m ^-3 .

The solution according to the invention makes it possible to eliminate the existing drawbacks when using precondensates of different types or some polyamines to precipitate lignin compounds, preferably lignosulfonic acids, from aqueous solutions. The advantage of this method lies mainly in the simplicity and speed of preparation of complex compounds of polyamine and polyamine diamines based on polyethyleneimines, which can be continuously prepared directly in the pulp and paper mill or sewage treatment plant, in instant precipitation and easy filterability of precipitation products, independent of precipitation on pH lignin compounds.

The following are examples of preparation and use:

Example 1

To 500 parts of a 50% aqueous ethyleneimine solution was added 4.5 parts of dichloroethylene with stirring for 1.5 hours. Thereafter, the temperature of the reaction mixture was raised to 100 ° C and maintained under constant stirring for 4 h. The solution thus prepared was diluted

2.5 X with water. From this solution, prepare 100 parts of 1% polyethyleneimine and add 20 parts of aluminum sulphate in a solution of 100 g Al ₂ (SO ₄ ) ₃ .18H ₂ O / l. A white precipitate of the polyelectrolyte complex compound A1 precipitates out of solution.

Example 2

The procedure is the same as in Example 1 except that 3.9 parts of dichlorobutane or 3.0 parts of dimethyl sulfate are used as catalysts. The polyethyleneimine solution thus obtained is reacted with aluminum sulphate in analogy to Example 1 to form a white precipitate.

Example 3

750 parts of ethyleneimine of about 50% aqueous solution are heated to 50 ° C and 7.5 dL of 34% HCl are added dropwise. After addition of the catalyst, the mixture was kept under stirring at 100 ° C for 4 h. After completion of the reaction and dilution to a 20% solution, the complex is prepared by reacting 20 parts of 100 g / l aluminum sulphate with 100 parts of 1% polyethyleneimine.

Example 4

150 parts of polyethyleneimines of a 50% solution prepared as described in Examples 1-3 are diluted with 350 parts of water and heated to 90-95 ° C with vigorous stirring. 11 parts of dichlorohydrin are then added successively. After 2 h, an additional 2 parts of dichlorohydrin were added and allowed to react for 0.5 h. After these additions of dichlorohydrin, the viscosity of the reaction mixture increased sharply and was stabilized by adding 100 parts of water and 4 parts of 50% NaOH solution. 10 parts are taken from the modified polyethyleneimine solution thus prepared, 190 parts water are added and mixed thoroughly. This solution is then mixed with 40 parts of 100 g / l of aluminum sulfate dissolved in water. A colorless viscous liquid having a pH of 5.5 to 6.0 is formed and can be used directly to precipitate lignin compounds from aqueous solutions.

Example 5

200 parts of polyethyleneimine, about 50% prepared by the procedures of Examples 1-3, are diluted with 300 parts of water and mixed with 1.5 parts of epichlorohydrin at room temperature. The temperature of the reaction mixture is then raised to 90-100 ° C and maintained under constant stirring for 2 hours. 190 parts of water are added to 10 parts of the solution, mixed and mixed with 40 parts of 100 g of aluminum sulphate dissolved in water. 1. A colorless viscous liquid of pH 5.5-6.0 is formed which precipitates the lignin compounds from their aqueous solutions.

Example 6

750 parts of about 50% ethylenimine are mixed with 50 parts of dimethylurea, heated to 50 ° C and 7.5 parts of 34% HCl are added dropwise. After addition of the catalyst, the reaction mixture is treated with 1200 parts of water. A viscous, yellowish liquid is formed. To the thus prepared 10 parts of modified polyethyleneimine, 190 parts of water are added, mixed and mixed with 40 parts of 100 g / l of aluminum sulphate dissolved in water. A colorless viscous liquid of pH = 5.5-6.0 is formed which precipitates the lignin compounds from their aqueous solutions.

Example 7

(a) 530 parts of water, 667 parts of a mixture consisting of 91,5% diethylenetriamine and 8,5% triethylenetetramine and 925 parts of adipic acid are mixed and heated in a nitrogen atmosphere at 150 ° C for 3.5 hours and maintained at that temperature for 5 hours until the water is distilled off. The polyamidamine formed is mixed at 1400C with 1400 parts of water (48.3% solids).

b) A resin solution containing 250 parts of 100% resin prepared according to 7a) is mixed with 16.5 parts of concentrated sulfuric acid and added at 80-85 ° C over 4 hours with 543 parts of a 50% aqueous solution of ethylenimine. After completion of the ethyleneimine dosing, the temperature of the reaction mixture was maintained at 80 ° C for 30 minutes. The dry weight of the material thus prepared is 50.2%, the specific gravity is 1.094.10 ³ kg.m ^-3, and the viscosity (measured on a HOPPLER viscometer at 25 ° C) is 753 mPa.s.

c) 750 parts of solution 7b) are diluted with an equal amount of water and 21.4 parts of epichlorohydrin are added over a period of 1.5 hours at 70 ° C. After stirring for another 1.5 h at 70 ° C, the reaction mixture had a viscosity (measured on a HOPPLER viscometer at 25 ° C and a dry weight of 20%) of 1.1 Pa.s, a specific gravity of 1% solution of 1.088.10 ³ kg.m ^-3 .

d) 190 parts of water are added to 10 parts of the resin prepared in 7c), mixed and mixed with 40 parts of 100 g / l of aluminum sulphate dissolved in water. A slightly yellowish viscous liquid is formed at pH = 5.5-6.0, allowing precipitation of the lignin compounds from its aqueous solutions.

Example 8 2 0 4 2 8 2 parts of cationic polyacrylamide are dissolved in 250 parts of water and 15 parts of conc. H ₂ SO ₄ diluted with 25 parts water. To this solution was then added 25 parts of a 50% aqueous solution of ethyleneimine and heated at 80-85 ° C for 2 h. After this time, 52 parts of epichlorohydrin were added to the reaction mixture and the mixture was heated at 80-85 for another 2 h. Deň: 32 ° C. The reaction mixture was then diluted by adding 300 parts of water.

parts of the above resin are diluted with 175 parts of water, mixed and mixed with 80 parts of 100 g / l of aluminum sulfate dissolved in water. A clear high-viscosity liquid is obtained which allows not only coagulation and flocculation of the suspended pulp and paper waste water but also precipitation of lignin compounds from the waste water.

Example 9

The resin prepared according to Example 7c) was diluted in a continuous mixer to a 0.5% solution. This solution is then continuously fed to a mixer where it is mixed 1: 1 with a 100 g / l aluminum sulfate solution (residence time of about 5 minutes to complete the reaction) and from there it is dosed directly into the mixer. waste water containing approximately 1% sulphite liquor. The dose is in the range of 3-5 liters of said solution per m ^{3 of} waste water. This results in a COD reduction of 25-40% and a lignin content of 30-70%, depending on the type of leachate contained in the waste water. The resulting precipitate has a granular character and is easily filterable.

Example 10

The modified polyethyleneimine prepared according to Example 6 and reacted with aluminum sulphate is metered into a 1% suspension containing sulphite pulp ground at 38 ° SR and 1 to 10% sulphite leach, calculated on the dry weight of the fibers used. The amount of the modified polyethyleneimine complex compound used according to Example 6 used is in the range of 0.3 to 3% dry matter per dry fiber. In tab. The mechanical properties of the sheets of papers made from such treated suspensions are shown. It can be seen from Table I that by applying the extract to the paper as a result of the chemical treatment of the wood, the mechanical properties of the paper such as tear, burst and tear strength are practically unchanged, but there is an increase in sizing, elongation and optical properties also vary (whiteness deteriorates), but only when using 5% or more dry matter of the sulphite liquor relative to the dry matter of the fibers.

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Table I

% leachate (% dry matter per fiber) coagulant basis weight g · m ^-2 marketable length m stand. stand. extend- getting married 0 / / 0 Noll sizing mm according to Ex. 6 (% dry per fiber) burst strength kPa tear strength mN - - 59 7813 110 980 2.55 0 1 0.3 57 7657 110 1020 2.70 0 1 3.0 58 6820 100 ALIGN! 940 2.57 0.4 10 3.0 59 7022 110 960 2.65 0.2

OBJECT OF THE INVENTION

Claims (1)

Process for the preparation of complex polyamine and polyamidamine compounds for the precipitation of lignin compounds from aqueous solutions, characterized in that the polyethylenimines of the general formula: R 3 R 3 R 3 IN— · CH5-C — NH— (cHs-C — Nil) —KI ^a 1 ² I n R 2 R 5 wherein R ₃ and R ₄ denote hydrogen or alkyl groups having 1 to 3 carbons, n is 2 to 5.10 ³ , R ³ denotes hydrogen or R »R _with H H - (CH - CH - NH - CH - CH - NH 11% 1 * 1) -R _e R 'R * R _a Π] = 0 to 1.10 ³ , where R ₅ denotes a bifunctional cross-linking radical - c — a — c —nh-b-nh-c-αν »» Or o where A is bifunctional radicals aliphatic - (CH ₂ ) _k -, k = 1 to 10, -CH = CH-, O-, m-, p-phthaloyl, and B is - (CH ₂ ) _X - NH / m - (CH ₂ ) _X -, wherein m = 0 to 3, x = 2 and R ₂ is hydrogen, R _t or R »R $ R H-NH-C-CH3) -NH-C-CH3-N1 -R _e R * R * H ₂ where n = 0 to 1.10, and R ³ _s are hydrogen, R ₅ or crosslinking bifunctional or polyfunctional radicals from compounds such as epichlorohydrin, derivatives of polyacrylamides, polyepoxides, dichlorobutene, dichlorobutane, dichloroethylene, or dichlorohydrin derivatives of diisocyanates and all compounds formed from urea, thiourea, guanidine or semicarbazide, thiosemicarbazide, dicyandiamide, melamine and their derivatives or mixtures thereof and lower aliphatic aldehydes of 1 to 4 carbons or dialdehydes of 2 to 4 carbons or fural and its derivatives, of formaldehyde, and forming up to 50% aqueous solutions, are reacted with 10 ^-3 to 1 equivalents of Al contained in water-soluble salts at normal temperature in an aqueous medium containing 10 ^-5 to 50%, preferably 0.1 to 1% by weight of the above polyethyleneimines and pH 3 to 7.