NZ270467A

NZ270467A - Acrolein homopolymer with a mw of 2000 - 6000, its production and use as a biocide

Info

Publication number: NZ270467A
Application number: NZ270467A
Authority: NZ
Inventors: Peter Werle; Mathias Hopp; Oswald Helmling; Dietrich Arntz
Original assignee: Degussa
Priority date: 1994-02-11
Filing date: 1995-02-08
Publication date: 1995-11-27
Also published as: NO950512D0; CA2142220A1; EP0667358A3; DE4404404A1; NO950512L; KR950032328A; ZA951114B; AU1168695A; JPH07242710A; EP0667358A2

Description

<div class="application article clearfix" id="description"> New Zealand Paient Spedficaiion for Paient Number £70467 270 7 : luoi'Uy Dat*>(o): U:2:.S.hr.. ;"'~~1 ;Complete Specification Filed: ...5:.?:.'.?.^ ;! Class: (G)...£i.Vai'&tr;..... ;S 7 N O V 1995 ;Publication Date: P.O. Journal No: ;Patents Form No. 5 ;Our Ref: JB204165 ;NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION ;ACROLEIN POLYMER ;N.Z. PATENT OFFICE ;-8 FEB 1995 ;received ;We, DEGUSSA A.G., a German Corporation of Weissfrauenstrasse 9, D—60311 Frankfurt, Federal Republic of Germany hereby declare the invention, for which We pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: ;PT0526295 ;(followed by page la) ;- 1 - ;27 0 4 6 7 ;1<=< ;Acrolein polymer ;This invention relates to an acrolein hcmopolymer, to a process for the production thereof, to a process for the 5 preservation of materials using the acrolein polymer and to a biocidal agent which contains the acrolein polymer. ;It is known to use monomeric acrolein (2-propenal) as a highly effective biocide in water systems against unwanted 10 algal and plant growth. It may also be used to combat sulphate-reducing bacteria in petroleum exploration. ;Because of its high reactivity, no further applications for the biocidal action of monomeric acrolein have yet been 15 found. Due to its tendency when incorrectly handled to spontaneously and sometimes explosively polymerise, particular safety precautions are required for handling. It is highly irritant to the respiratory tract and eyes. Even when stabilised, acrolein may be stored for only a limited 20 period. ;It is known to use copolymers of acrolein with formaldehyde produced by condensation of -acrolein and formaldehyde in a molar ratio of between 1:1 and 1:10 in the presence of a 25 basic catalyst as biocides for aqueous systems ;(DE-B 32 05 487). The known copolymer of acrolein with formaldehyde has the disadvantage that it contains approximately 15% formaldehyde. ;3 0 It is known to use acrolein homopolymers as biocides ;(EP-A 0 33 9 044). Polymerisation is predominantly performed by free-radical or ionic means using a sodium hydroxide solution. ;35 Disadvantageously, free-radically polymerised homopolymer ;Off, ;of acrolein are virtually insoluble in organic media o water and exhibit only very low biological activity the ;(followed by page r^) ;27 0 4 6 7 ;10 ;15 ;form of an aqueous suspension. An aqueous suspension of the anionically polymerised acrolein described in example lb of EP-A 0 339 044 also exhibits only inadequate activity against microorganisms. ;For toxicological reasons, the described solution in methyl alcohol is not suitable for the production of products which may be handled. It also exhibits only moderate biocidal activity. ;The process described in EP-A 0 33 9 044 of adding a catalyst to an acrolein solution cannot be performed industrially due to the highly exothermic reaction which is spontaneously initiated. ;There is thus an object of providing an acrolein polymer which is toxicologically harmless and safe and exhibits elevated biocidal activity. ;2 0 The present invention provides an acrolein hcmopolymer, which is characterised in that it has the following physicochemical parameters: ;T n i Mi ^ ;Weight average ,—= Mw ;* E ni Mi wherein ni means number of mol and Mi means molecular weight 25 Mw: 2000 - 6000 D Carbonyl content: 0.5-5 mol/kg of polymer. The present invention also provides a process for the production of the acrolein polymer, which process is 3 0 characterised in that acrolein and catalyst are simultaneously added to a reaction medium in a vessel in such a manner that the temperature of the reaction medium does not exceed 25°C and the pH value of the reaction medium is 10 to 11, the mixture is stirred on completiq^of^F /X 3 5 addition and the acrolein polymer separated. 94 114 A C 2704 3 U In a preferred embodiment of the invention, water may be used as the reaction medium. An aqueous sodium hydroxide solution with a concentration of 0.01 to 10 mol/1 may be used as the catalyst. The temperature of the reaction 5 medium may preferably be 20 to 25°C. The ratio of acrolein to catalyst may be 1:0.0001 to 1:0.05. The stirring time may be 1 to 3 hours, preferably 1 to 2.5 hours. The solid may then be isolated from the resultant aqueous 10 polyacrolein dispersion with a content of approximately 5 -to approximately 30% at acceptable space-time yields if the pH is adjusted to the required range during the reaction. The polymer may readily be centrifuged in centrifuges of a conventional design and any residual acrolein may be 15 eliminated from it by careful washing with water. The still moist product discharged from the centrifuge, with a water content of approximately 35%, may readily be dissolved at 40 to 50°C within a short time in many 2 0 polyhydric alcohols, such as propylene glycol, butylene glycol as well as glycols of the general formula HO (CH2CH20) nH. Ethylene glycol and propylene glycol and the oligomers or ethers thereof are preferably used. The resultant solutions may have a polymer content of up to 25 30 wt.%. They are clear, colourless or slightly yellow in colour. These solutions in (HO (CH2CH20) nH) are furthermore non-toxic, virtually odourless and constitute effective biocides. 3 0 Dipolar aprotic solvents, such as acetone, dimethyl sulphoxide, methylpyrrolidone, dimethylformamide, tetramethylurea may also constitute good solvents for the polymer. 3 5 When used in many areas, such as the preservation of dye dispersions, glues, textile auxiliaries, wax emulsions, 94 114 Ac 270 wood protection lacquers and many others, these solutions may be homogeneously distributed by stirring. It is also technically possible to convert the moist 5 centrifuged product into a dry biocidally active powder, by using a disk drier preferably operated under a vacuum. Due to the low bed depth on the individual disks and careful movement by the raking arm, a very fine product may successfully be obtained. The drier is operated at 10 - temperatures of 20 to 50°C under a pressure of 1 to 100 mbar. Using a fluidised bed drier has been found to be another method of resolving the drying problem. Due to the elevated 15 air throughput and vigorous mechanical friction of the individual particles of the product against each other, this method yields an exceptionally finely divided powder which may be directly packed without further grinding. 20 In fluidised bed drying, it has been found to be advantageous to use a temperature program, wherein drying is initially started at a low temperature which is raised in stages. Drying is preferably begun at room temperature and the drying temperature is increased to up to 75°C. The 25 polymer obtained using this drying process is a slightly yellow powder with a primary particle size of a few micrometres. It is possible to use "the acrolein polymer according to the 3 0 invention as a preservative or biocide by direct incorporation, but the use of solutions in polyhydric alcohols of the type described above may here too be advantageous. When these solutions are poured into aqueous media, the polymer precipitates, which in the event of 3 5 inadequate homogenisation may lead to a loss of biocidal activity. 94 114 A\c 2704 5 It has surprisingly been found that by adding a small quantity of an inorganic or organic base to the alcoholic solutions it is possible to obtain water-dilutable or at least microdisperse systems with only a weak Tyndall 5 effect. 0.05 to 0.1 mol of base may be used for 1 kg of a 10 wt.% solution of the polymer. An aqueous solution of sodium hydroxide is customarily used. Na-alkylates may, however, also be used. In addition to improved solubility, a distinct increase in disinfective action has also been 10 found in short-term testing. The solutions may thus be stated to be activated by the hydroxyl ions. This property of the polyacrolein depends in a surprising and unpredictable manner upon the drying conditions. Products which have been dried at room temperature or <; 60°C and 15 optionally ground do not exhibit the solubilising effect due to the addition of a base. Only those preparations dried using the process according to the invention with a strong air current at final temperatures of > 60°C, preferably at 75°C, are alkali-soluble. 20 The present invention also provides a process for the preservation of materials, which is characterised in that the acrolein polymer according to the invention is added. 25 The acrolein polymer according to the invention may, in particular, be added to the following materials: plastic dispersions, anti-fungal treatment solutions for wood, cladding and walls, wall paints, dye pastes and the 3 0 like, sealing compounds, distempers, wood protection lacquers, adhesive emulsions, skin and leather glues, bone glues, starch glues, casein glues, dextrin adhesives, salted skins, pickling solutions, dried skins, tanning liquor, moist chromium leather, finished leather, spinning 35 baths, wax emulsions, wax raw materials, textile finish (anti-fungal), textile dressings, paper/paperboard (antifungal) , PVC coating (anti-fungal), drilling and cutting 270467 oils (diluted), drilling and cutting oils (concentrated), wood preservatives, cellulose fibres (rotproofing agent), grouting cement, marine paints or liquid cleansers. 5 The acrolein polymer according to the invention may here be added to the materials in quantities of 0.01 to 0.3 wt.%. The present invention also provides a biocidal agent which contains the acrolein polymer according to the invention. 10 The biocidal agent may here contain the acrolein polymer according to the invention dissolved in a polyhydric alcohol, for example ethylene glycol (for example as a 10% solution). The biocidal agent may additionally contain an oxidising agent, such as H202 or peracetic acid and 15 optionally an alkali metal hydroxide, such as NaOH. In another embodiment of the invention, the biocidal agent may contain an inorganic or organic base, such as for example NaOH or sodium alkylates (for example sodium 2 0 methylate). The biocidal agent may contain the acrolein polymer according to the invention in a 20% dispersi water. In predominantly aqueous systems and in the event 25 inadequate mixing during incorporation, the dissol polymer may precipitate in coarse particles and so rise to reduced biocidal activity. It has now been found that the polymer solutions containing 30 glycol may be modified by treatment with small quantities of oxidising agents, such as hydrogen peroxide or peracetic acid, with, optionally, subsequent addition of sodium hydroxide solution in such a manner that water-soluble or microdisperse systems are produced which do not exhibit the 35 possible disadvantages caused by precipitation. The added quantity of oxidising agents, used in a 10 wt.% polymer solution containing 100 g of solid polymer, may be 0.1 mol 94 114 AC 27 04 7 to 0.4 mol, preferably 0.2 mol to 0.3 mol of pure oxidising agent. The optionally added base solution is preferably used in quantities of 0.05 to 0.1 mol (as NaOH). 5 Examples Example 1 (comparative example) Example lb according to EP-A 0 339 044 is replicated and 10 the resultant dry polyacrolein is dissolved in methanol (10% active ingredient content). A portion of the solution is evaporated and redissolved in methanol (c.f. EP-A 0 399 044, example la): 15 The process described in EP-A 0 339 044 is ruled out for industrial use on safety grounds. If, in contrast, the catalyst, in general an aqueous inorganic base or a basic amine, is placed in the reaction vessel and the acrolein is added to it with vigorous external cooling in such a manner 2 0 that the temperature in the reaction vessel does not exceed 25°C, colourless to slightly yellow precipitates are obtained which are only sparingly or incompletely soluble in the solvents according to the invention. Insoluble fractions of polymer remain even at elevated temperatures 25 (80°C). Exposure to elevated temperatures moreover causes undesirable discoloration of these solutions. Example 2 (according to the invention) 30 330 ml of water and 2.0 ml of IN NaOH are introduced into the reaction vessel and 120 ml of acrolein and 6.8 ml of IN NaOH diluted with 60 ml of water are steadily apportioned over the course of approximately 3 0 minutes with cooling to 5 to 20°C. The mixture is stirred for a further 1 hour at 35 room temperature, the solid polymer separated, washed carefully with water and the polymer stirred into 700 g of ethylene glycol heated to 45 to 50°C. After approximately 94 114 AC 8 30 to 60 minutes, a light yellow, clear polymer solution with an active ingredient content of 10% is obtained. When this solution is poured into water, a heavy precipitate is formed. The polymer (dried under vacuum at room temperature after separation) has a carboxyl content of 0.7 mol/kg and a weight average of Mw = 3500 D. 10 Example 3 100 g of a polyacrolein solution produced according to example 2 are combined at 20 to 25°C with 4.5 ml of a 30 wt.% H202 solution and heated to 70 to 75°C. The solution 15 is held at this temperature for 1 to 2 hours. When such a solution is poured into water, only slight turbidity is now visible. Post-oxidation with H202 thus leads to improved solubility in aqueous systems. 20 Example 4 125 1 of water are introduced into a reaction vessel and combined with 5 1 of a 1% NaOH solution. The solution is cooled to +5°C. 25 1 of acrolein and 5 1 of 1% NaOH 25 solution are added in such a manner that the internal temperature does not rise above +25°C. The reaction mixture is stirred for a further 2 hours and then centrifuged. The solid is washed and cooled in the centrifuge. 3 0 24 kg of moist powder are obtained which are dried in two batches in a fluidised bed dryer using the following 5 program: 1 h 25°C 35 1 h 35°C 3 h 75 °C. 94 114 &C A-, „ 27O40 9 A total of 15 kg of dry polymer are obtained with a carbonyl content of 2.2 mol/kg and a weight average Mw of 4000 D. 5 Example 5 A polymer produced according to example 4 is dissolved in ethylene glycol with heating and 100 g of this 10% solution are combined with 200 mg of NaOH (dissolved in a little 10 water) or with 300 mg of solid NaOCH3. While the solution which had not been treated with alkali exhibited heavy precipitation of polymeric acrolein when poured into water, the solution treated with OH" exhibited only slight turbidity. This means that solubility in water is improved 15 by the addition of OH" ions. The microbicidal activity of the resultant preparation is determined using the so-called "time-kill-test" (TKT). In this test, which was performed following the 2 0 recommendations of the American Petroleum Institute (API, RP 38, 2nd ed., Dec. 1965), a highly concentrated microbial suspension (microbial count 106 to 108) is combined with the desired quantity of biocide and incubated for 24 hours at 25°C. The suspension is then inactivated and a geometric 25 dilution series of up to 6 is prepared; one 1 ml of each dilution is mixed with 10 ml of nutrient agar on plates and incubated for 48 hours at 37°C. The kill rate is calculated by counting the number of colonies. 30 The results are evaluated as follows: The arithmetic mean of 2 values (two determinations) is calculated. The microbial reduction value KRt per unit time in the TKT (24 h), also known as the rating value, is 35 calculated using the following equation: log CFU(controj) - log CFU(d) </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 94 114 AC 270 10 CFU(control) = the number of CFU/ml without the action of the preparation (also known as the blank sample) 5 CFU(D) = the number of CFU/ml after the action of the preparation. Good activity entails achieving reductions of at least 5 log increments. 10 Type of microbe: Pseudomonas aeruginosa ATCC 15442 15 Example n° Temp. pH Time [h] Cone. [ppm] KRt 1 25 6.5 24 500 2 . 8 (comparison) la 25 6.5 24 500 5 . 8 2 25 6.5 24 500 > 7.4 3 25 6.5 24 500 > 7.4 4 25 6.5 24 500 > 7.4 25 6 . 5 24 200 3 . 0 5 25 6.5 24 200 > 7.4 20 27 0 4 6 7 11 WHAT WE CLAIM IS:

1. Acrolein homopolymer which is characterised in that it has the following physicochemical parameters: Y1 T1 7 /W 7 ^ Weight average , = Mw 3 E ni Mi 5 wherein ni means number of mol and Mi means molecular weight Mw: 2000 - 6000 D Carbonyl content: 0.5 - 5 mol/kg of polymer. 10

2. Process for the production of the acrolein polymer according to claim 1, which process is characterised in that acrolein and catalyst are simultaneously added to a reaction medium in a vessel in such a manner that the temperature of the reaction medium does not exceed 15 . 25°C and the pH value of the reaction medium is 10 to 11, the mixture is stirred on completion of addition and the acrolein polymer separated.

3. Process for the preservation of materials, which is 20 characterised in that the acrolein polymer according to claim 1 is added to these materials.

4. Preservation process according to claim 3, characterised in that the acrolein polymer is added to 25 the following materials: plastic dispersions, anti-fungal treatment solutions for wood, cladding and walls, wall paints, dye pastes, sealinq compounds, distempers, wood 3 0 protection lacquers, adhesive emulsions, skin and leather glues, bone glues, starch glues, casein glues, dextrin adhesives, salted skins, pickling solutions, dried skins, tanning liquor, moist chromium leatheje^-^f" finished leather, spinning baths, wax emulsions,//wax / ' ^ I • 11 v. 35 raw materials, textile finish (anti-fungal), textile 270 12 dressings, paper/paperboard (anti-fungal), PVC coating (anti-fungal), drilling and cutting oils (diluted), drilling and cutting oils (concentrated), wood preservative, cellulose fibres (rotproofing agent), grouting cement, marine paints or liquid cleansers. Biocidal agent characterised in that it contains acrolein polymer according to claim 1. Biocidal agent according to claim 5, characterised in that the acrolein polymer is dissolved in a polyhydric alcohol. Biocidal agent according to claim 5 or claim 6, characterised in that it contains an oxidising agent and optionally sodium hydroxide solution. Biocidal agent according to claim 5 or claim 6, characterised in that it contains an inorganic or organic base. Acrolein homopolymer according to claim 1, substantially as herein described. Acrolein homopolymer according to claim 1, substantially as described with reference to any Example thereof. Process according to any one of claims 2-4, substantially as herein described. Process according to claim 2, substantially as described with reference to any Example thereof. Biocidal agent according to any one of claims 5-8, substantially as herein described. 270467 13 Biocidal agent according to claim 5, substantially as described with reference to any Example thereof. DBGPSSA A.G. / By its Attorneys TtAT.nwiN, SON & CAREY </div>