CA1173631A

CA1173631A - Use of polyethyleneimine for absorbing odorous substances

Info

Publication number: CA1173631A
Application number: CA000392735A
Authority: CA
Inventors: Holger Meyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-12-18
Filing date: 1981-12-18
Publication date: 1984-09-04
Also published as: IT8125684A0; IT1142135B; WO1982001993A1; GB2102292B; NL8120479A; ES508649A0; GB2102292A; SE448148B; BR8108919A; FR2497670A1; AU7934582A; GR76970B; CH658392A5; SE8204681D0; FI822843L; FI822843A0; SE8204681L; AU550277B2; DE3047774C2; FI76495C

Abstract

USE OF POLYETHYLENEIMINE FOR ABSORBING
ODOROUS SUBSTANCES

ABSTRACT

A method is disclosed for absorption of odorous substances comprising binding the odorous substance to polyethyleneimine. The polyethyleneimine may be in the form of an aqueous solution containing 0.1 to 10%
polyethyleneimine and the polyethyleneimine may be used in combination with other odor absorbing substances.

Description

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USE OF POLYETHYI.ENEIMINE FOR ABSORBING
ODOROUS SUBSTANCES
_ _ _ _ The present invention relates to the use of polyethyleneimine for absorbing odorous substances.
It is known in the art that various compounds, such as esters of acrylic acid and fumaric acid, with long chain polyterpene alcohols are capable of binding a large number of compounds with olfactory activity in complex or chemically bound form and therefore are suitable as odor adsorbers. It is also known that zinc ions and zinc compounds, such as zinc ricinoleate, can enter into stable bonds with mercaptans and amines. Additionally, bactericides have been used in various areas for eliminating odor forming microorganisms.
It has now been found :that polyethyleneimine is excellently suitable ~or orming stable absorption -compounds with fatty acids, aldehydes and ketones, thus causing them to be non-odorous.
It is an object of the present invention to provide polyethyleneimine for use in absorbing odorous substances.
The most important requirements for an odor absorption agent are good efficacy at low application levels, economy, freedom from inherent odor, toxicologic safety, compatibility with the materials to be treated an~ biodegradability. These requirements are ideally fulfilled by polyethyleneimine.

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Polyethyleneimine is produced by polymerization of ethyleneimine. The degree of polymerization of the poly-ethyleneimine used in accordance with the invention must be sufficiently high that the polyethyleneimine is toxicologically unobjectionable. With an increasing degree of polymeriæation, the water solubility of the polyethyleneimine decreases.
Although the degree of polymerization of the polyethylene-imine used in accordance with the invention is subject to no restrictions other than the previously mentioned minimum .
O degree of polymerization, ethyleneimine polymers which have adequate water solubility are preferred for reasons of ease of handling. Suitable polyethyleneimines are commercially available and their characteristics are sufficiently known to those skilled in the art. (See, for example, Ullman 1 5 'o Encyclopedia of Industrial Chemistry, 3rd ed., p. 144, col. 3, e.g. Polymin P, BASF trademark.) The use of polyethyleneimine in accordance wlth the present invention may be accomplished in various ways.
The amount of polyethyleneimine to be used is dependent _0 upon the concentration of the odorous substance to be absorbed in the medium to be treated. For ease of handling, the u~se of aqueous polyethyleneimine solutions is preferred. Althou$h the polyethyleneimine concentration of the solution is not critical, a polyethyleneimine concentration in the range ~~ of about 0.1 to 10% is preferable from an economic point of view and a concentration of 1-3% is more preferable.
However, good results are obtainable at polyethyleneimine concentrations in the range of 0.01%.

"' Solutions of polyethyleneimine in water or other solvents, as well as mixtures thereof, suitable for spraying or misting are preferably used in the present invention. Another 3~)3~

preferred embodiment of the present invention involves im-pregnating materials which come in contact with odorous substances with polyethyleneimine. Materials which may be impregnated with polyethyleneimine include fabrics, filters or filter masses, objects such as shoe insoles and the like.

r:xperiments performed have shown that polyethyleneimine binds almost completely with fatty acids, aldehydes and ketones, even when only short contact times are available.
~erein this-specification reference is made to a binding of the odorous subs~ance to the polyethyleneimine, the word "binding" is intended to apply broadly to situations involving chemical reaction, addition reactions, formation of complexes or any other reaction involving a combination of the odorous substance with the polyethyleneimine. In contrast, the absorption of amines and sulfides is less vigorous and longer contact time is required for fully satisfactory results. Therefore, it is frequently advantageous to use the polyethyleneimine employed in accordance wlth the present invention with other odor ab-sorbing means to ensure that compounds such as amines and sulfides are also completely absorbed when contact time is short. Thus, the polyethyleneimine can be used alone or in combination with other odor absorbing agents, and depending on the intended use, in combination with other customary substances.

Polyethyleneimine may be used for absorption of odorous substances in almost every circumstance where odor elimination is desired. Preferred areas of application include cosmetics and hygiene, industrial odor control and home air deodorization.
For example, polyethyleneimine can be used in deodorants For the human body. As another example, shoe insoles can be im- 7 pregnated with polyethyleneimine. The use of polyethylene-imine for odor control in sewage treatment plants is of particular importance, especially for treatment of the effluent air produced in such plants. The use of polyethylene-imine in accordance with the present invention, particularly - provides a municipality with means for freeing neighbors of r ~ 36~

municipal sewage treatment plants from the oten highly un-pleasant odor stress in a simple and inexpensive manner.
Additional application areas suitable for odor elimination with polyethyleneimine include barns, animal rearing units, hospitals and chemical plants.

Another important area for the use of polyethyleneimine as an odor absorber in accordance with the presen~ invention is as a room~air deodorizer. For exa~ple, polyethyleneimine solutions can be sprayed into ducts, conduits and shafts of ) air conditioning and air eirculating systems, resulting in continuous elimination of troublesome and undesirable odorous substances. As another area of use, filters impreg-nated with polyethyleneimine can be used in plants, such as the sewage treatment and chemical plants previously mentioned, ~5 and in effluent air purification plants. Such use reduces the required fresh air supply, which in turn leads to energy sav-ings. In private households the use of polyethyleneimine solutions in the form of sprays for odor improvement is par-ticularly useful in such areas as bathrooms and kitchens.

:~0 Example 1 The absorption of a series of odorous materials using poly-ethyleneimine was investigated. For this purpose, about 50 g. of absorbent cotton was saturated with 100 ml. of a 1.5% aqueous polyethyleneimine solution, then air dried for ~5 24 hours. The treated ~aterial was introduced into a closed system with a volume of about 300 ml. The air present in the closed system was circulated by means of an integrated membrane pump. In each case, 0.01 g. of an odorous material, as listed in Table I was supplied into the system.

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The gas stream in each case was examined by gas chromo-tography and organoleptically before and after being passed over the polyethyleneimine impregnated absorbent ootton.
The results obtained are summarized in Table I

Table I
Odorous ~laterial Absorption Or~an~lep~c (V/ ) P~esul~ s '~

Butyraldehyde 97 O
Iso~utyraldehyde . 91 Formalàehyàe 95 Diacetyl 92 0 Acetone 100 O
Propionic acid 100 O
Butyric acid 100 O
~7alerianic acid 100 O
Isovalerianic acid 85 Mlethylamine 32 3 Ethylamine 35 3 ' Propylamine 42 3 ~~ Butylamine 51 4 Mlethyl sulfide . 16 4 Ethyl sulfide 22 4 Butyl sulfide . 31 ~O = odorless

2~ . 1 = b~rely perceptible 2 = typically pérceptible

3 = highly perceptible

4 = very highly perceptible . . ....... ............... , .. ................... - . . ..... -.. . .

The experimental results in Table I demonstrate that fatty acids, aldehydes and ketones are almost completely bound by polyethyleneimine, while amines and sulfides are only partly bound. With longer residence times of the gases in the absorber phase, however, these substances can also be removed to a great extent, resulting in organoleptic fincdings of between 0 and 2.
Example 2 The eficacy of polyethyleneimine can be supplemented by adding other absorbents, such as zinc sulfate, zinc ricinoleate, soda and zinc carbonate. The emerging air mixture, as described in Example 1, is then free from all~odorous substances used.
A typical formulation may be composed as follows:

1.5 g. polyethyleneimine .5 g. Na2C03 94 g. water About 50 g. absorbent cotton were saturated with the above mixture, then dried. The cotton mass treated in this manner was sufficient to purify lnO0 m3 of air containin~ 200 ppm of o~orous substances.
The cotton, saturated with oclorous substances, can be destroyed in an environmentally safe manner hy burning.

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Example 3 For use in air filters suitable substrates like cotton mats, felt mats, paper, and plastic mats are treated with an aqueous solution containing 1 to 2% by weight of polyethyleneimine and positioned in an air flow.
Alternatively, activated charcoal is treated (soaked or sprayed) with said solution and put into a suitable frame which again is positioned in an air flow.

Example 4 An aqueous solution containing 0.1 to 2.0 % by - weight polyethyleneimine is introduced into an airflow cycle or an air outlet (e.g. air-conditioning, effluent air) by atomization or such solution is sprayed onto the surface of a sewage clearing bath or introduced into the air-suction of such a bath.

~xample 5 Formulations for cosmetic applications:
a) Deodorant-spray 1.0 weight % polyethyleneimine 0.2 weight % isopropylmyristate 0.2 weight % perfume oil 7.6 weight % ethanol 91.0 weight % distilled water ~liS composition is filled as a pump spray using , a "press-pack" - system or propellant.

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b) Roll-on-Deodorant 1.5 weight % polyethyleneimine 7.0 weight ~ ethanol 3.0 weight % glycerine 2.5 weight ~ cellulose ester 0.3 weight % perfume oi.1 85.7 weight % distilled water c) Compositions a) and b) can be added in the production of soap, especlally the finishing of soap.
Example 6 Useful formulations for room air deodorization are the follow~ng compositions:

A B

1.0 2.5 weight % polyethyleneimine 0.5 1.0 weight ~ perfume oil 2.0 4.0 weight % emulsiier - 96.5 92.5 weight ~ distilled water 100.0100.0 Formulation A is filled using a "press-pack"-system, w~lile formulation B is illed together with propellant in a weight ratio of 70:30.
Example 7 Polyethyleneimine is put into plasticoam or plasticparts at 0.1 % to 2 % by weight.

In all examples polyethyleneimine so called Polymin P and Polymin SK from the company l'BASF" has been used.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method for absorption of odorous substances comprising contacting said odorous substances with a solution containing polyethyleneimine and binding the odorous substance to said polyethyleneimine, the polyethyleneimine being polymerized to a sufficiently high degree to be toxicologically unobjectionable.

2. A method according to claim 1, wherein an aqueous solution containing 0.1 to 10% by weight of said polyethyleneimine is used.

3. A method according to claim 1, wherein an aqueous solution containing 1 to 2% by weight of said polyethylene-imine is used.

4. A method according to claim 1, 2 or 3, wherein a solution of said polyethyleneimine in the form of a spray mist is used.

5. A method according to claim 1, 2 or 3, wherein said odorous substances are contacted with a material which is impregnated with said polyethyleneimine solution.

6. A method according to claim 1, 2 or 3, wherein said odorous substances are contacted with a filtering material which is impregnated with said polyethyleneimine solution.

7. A method according to claim 1, wherein said polyethyleneimine is used in combination with other odor absorbing substances.

8. A method according to claim 7, wherein said other absorbing substances are selected from the group consisting of zinc sulfate, zinc ricinoleate, soda and zinc carbonate.

9. In a method of deodorizing a substance which in-cludes an odorous organic component, the step which comprises contacting said component with polyethyleneimine solution in an amount and for a time to cause said odorous component to combine with said polyethyleneimine, the polyethyleneimine being polymerized to a sufficiently high degree to be toxicologically unobjectionable.

10. A method according to claim 1 wherein said polyethyleneimine is used in combination with other odor absorbing substances and perfume.

11. A method according to claim 10 wherein said other absorbing substances are selected from the group consisting of zinc sulfate, zinc ricinoleate, soda and zinc carbonate.