AU640622B2 - Gel-form deodorizer containing chlorine dioxide - Google Patents

Description

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p( OPI DATE 26/06/9i AOJP DATE 08/08/91 JAPPLN. ID 46389 89) PUT1 NUMBER PCT/JP89,'01215 (51) 004r: 5 (1 MJW O9/79 A61lL 9/01 AlWO9/79 (43) 99IJE 1991*6 M 138 (13. 06. 1991) (21) 9M!1f~ (22) [E tb F POT/JP89/01P1 19 89F1 2A4B( 04. 12. 89 j, 40 0 7-r f *kO1 (A IKOH- 0CO., LTD.)C J P/JP) T110 3K~83F1.MT134 Tokyo. (JP) (72) AW1 J6 ZU 944 (17/AH-ASHI, T ak a sh i) CJ P/JP) 7:229 jtPI1!A4Mqt1!Ml1"3T01 01174 Kanagawa. (JP) (74) ftg/k -*fIg± )A*Wf M. A YA I TA.Sh ig e ru e t at.I 7 10 5 W RUV1 IT 1 5-9- eAS1J Tokyo, UJP) (81) AMR JP, KR, SE(04,), US.

(54)TIt. '1RL-FORM DEODORIZER CONTAINING CHLORINE DIOXIDE (57) Abstract This invention provides a gei-form deodorizer containing chlorine dioxide prepared by the gelation of a stabilized aqueous chlorine dioxide solution using both a polyethyleneimide of a molecular weight of ten to hundred thousand and an epoxide crosslinking agent. This deodorizer is useful for deodorizing sulfur compounds and has a high strength, a long-term stability and a good handlability including exchange thereof because of the solid gel form thereof.

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la THIS INVENTION relates to the gelation of a stabilised chlorine dioxide. The gel thus formed has an excellent capacity for oxidizing a wide range of odour producing sources, both industrial and domestic, particularly acidic odour-generating substances, namely sulfur-containing compounds such as hydrogen sulfide and mercaptan, and is useful in making such sources entirely odourless. When the stabilised chlorine dioxide is converted to the gel by gelation, it has the advantage of good handlability when used as a deodorizer, namely a deodorant composition, and the advantage that the time when it is necessary to replace the deodorant composition with a new one can be visually determined because the gel becomes smaller in volume as time passes.

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There are many known processes for deodorizing bad odours. These may be mainly classified into the four methods mentioned below: Physical methods utilizing adsorbers, for example active carbon (adsorption mechanism).

(ii) Methods which rely on chemical reactions such as oxidation and neutralization with chemical substances.

(iii) Biological methods utilizing microorganisms.

(iv) Masking methods utilizing fragrances.

The deodorization mechanism of chlorine dioxide is believed to be an oxidLizing reaction which falls within method (ii) above. The existence of chlorine dioxide was first mentioned in a publication by R. Chen-vix in 1802 and its actual preparation was reported in 1815/1816. Chlorine dioxide is a very explosive and corrosive compound and is difficult to store and transport. Therefore, when required for use, chlorine dioxide had to be produced directly by the user. However, in view of it's excellent properties, such as oxidizing, bleaching and antibacterial, extensive studies were conducted with chlorine dioxide in an attempt to find a product which could be easily handled by everyone. As a result of such studies, stabilised chlorine dioxide was prepared which incorporated a stabilising agent, such as an alkali or an alkaline earth compound. The aqueous stabilised chlorine dioxide solution was adjusted to a pH of from 7.5 to 10.0 and made acidic or neutral by the addition of an acidic substance. It is believed that the antibacterial activity of stabilised chlorine dioxide is better in an acidic range than in an alkaline range. General considerations on the effect and activity of stabilised chlorine dioxide are disclosed in several articles see J. Odor Research and Eng. vol. 19, pages 328 to 331 (1988); vol. 20, pages 81 to 85 (1989)].

Commercially available aqueous stabilised chlorine dioxide solution has a concentration of about 50,000 ppm o (approximately at its maximum. This is the product which was employed in this invention.

Stabilised chlorine dioxide has mainly been used in liquid form. A solid stabilised chlorine dioxide is known in which a stabilised chlorine dioxide solution is adsorbed on and impregnated into a solid carrier such as zeolite, silica gel, calcium silicate, or the like see Japanese Patent KOKAI No. 63-147468). In the case of aqueous stabilised 3 chlorine dioxide solution, it is used in a conventional manner, e.g. by spraying. It is therefore inconvenient to use the liquid chlorine dioxide domestically since it exerts a strong and irritating chlorine smell. In the case of solid stabilised chlorine dioxide adsorbed on and impregnated into a solid carrier such as zeolite, used, for example, for the deodorization of refrigerators, it is difficult to ascertain when the deodorizing activity thereof has diminished.

Furthermore, the solid form has stability problems.

In view of the prior art teaching see Japanese Patent Publr. No. 1-38151), it was observed that a storage period of more than one month was not possible for solid stabilised chlorine dioxide which was obtained by adsorbing on and impregnating into a solid carrier such as zeolite and silica gel, followed by the addition of an acidic substance to the stabilised chlorine dioxide for the activation of the latter. Typical examples of acidic substances include solid acids such as alumina and silica-alumina, mineral acids such as hydrochloric acid and sulfuric acid, and organic acids such as oxalic acid and citric acid.

We, the present inventors, have undertaken extensive research in an attempt to resolve said technical problems, and *0 we have now found that the aqueous stabilised chlorine dioxide solution can be gelled with the combined use of a polyethylene-imine having a molecular weight of from 19C00 to *0 100,000 and an epoxide crosslinking agent, and that the transparent gelled product which is obtained has increased

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strength, io entirely free of the smell of, and has long-term 4 stability.

According to the present invention, there is provided a deodorant composition in the form of gel containing chlorine dioxide, which composition is prepared by gelling ai\ aqueous solution of stabilised chlorine dioxide with from 1 to by weight of a polyethylene-imine having a molecular 10,000 weight of fromXZ to 100,000 and from 0.5 to 15% by weight of an epoxide crosslinking agent.

Characteristically, to have effective antibacterial and oxidizing activity, the aqueous chlorine dioxide solution is maintained at a pH value between neutral and acidic.

However, because of this acidity, the chlorine dioxide evaporates and is carried into the air which means that the solution has very Fpor preservative properties. On the other hand, an aqueour solution of polyethylene-imine is alkaline, that is, it has a pH of about 11 at 5% by weight solution because of the presence of nitrogen atoms within the molecules, and the use of a polyethylene-imine solution is therefore very convenient for the storage of the chlorine doxide solution. The polyethylene-imine used according to e this invention has a molecular weight range of from 10,000 to 00,000 and preferably from 20,000 to 70,000.

Regarding the lower molecular weight limit of the polyethylene-imine, it is possible to carry out the gelation of the stabilised chlorine dioxide by using a polyethylene- *9* imine having a still lower molecular weight of about 1,000, but it then becomes necessary to use a larger volume of polyethylene-imine, for example in an amount of 30% by weig polyethylene-imine, for example in an amount of 30% by weight or more, and this has the disadvantage that it results in a brittle gel which is of little practical use. On the other hand, when gelation of the stabilised chlorine dioxide is effected using polyethylene-imine having a molecular weight of more than 10,000 and less than 100,000 in an amount of 20% by weight, the resulte.nt gel is particularly suitable for the deodorization of bad odours. With regard to the upper molecular weight limit for the polyethylene-imine to be used, commercially available polyethylene-imirve in Japan h.as a molecular weight of 100,000.

Typical examples of epoxide crosslinking agents include compounds containing two or more epoxide groups such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, polyglycerol polyglycidyl ether, glycerol polyglycidyl ether and diglycerol polyglycidyl ether.

As previously noted, the polyethylene-imine compound S and the epoxide compound are used in amounts of 1 to 25% by S weight and 0.5 to 15% by weight, respectively. In an amount less than the lower limit thereof, the degree of gelation is insufficient, and in an amount higher than the upper limit thereof, the degree of curing is in excess of that desired, :25: and the rate of deodorization reaction decreases. In both cases, therefore, the resultant gel product does not have any practical utility.

practical utility.

000*** 0 0 U, A{ i/t r ,I rc2 The deodorant gel composition according to this 6 invention can be prepared by admixing together 2 to by weight, preferably 2 to 87.5% by weight of an aqueous stabilised chlorine dioxide solution, 1 to 25% by weight, preferably 2 to 20% by weight, of a polyethylene-imine having a molecular weight of from 10,000 to 100,000, and 0.5 to by weight, preferably 1.5 to 10% by weight, of an epoxide crosslinking agent, optionally in an aqueous medium, at ambient temperature and under normal pressure in a reaction container made of glass, polyvinyl chloride or stainless steel.

e e o* *oo eo *o* *ooo i f v oo 7. J a '7 In preparing the gel-form deodorant composition of this invention, the crosslinking reaction, namely gelation reaction between po lyethylene-imine and enoxide compound is, as an example, deemed to proceed with as follows.

Thme nolyetnvlene-irnine to be used contains >1N NH and -NH 2 groaps within the molecular backbone thereof. Amongst those grollos, >'NH and -NH 2 groups react with enDoxide riLngs in the epoxide compound to co'duct an additon 'ec; on between them as represente b h olwn reaction formula: .NH NH

CH

2

CH

2

CH-CH

2 O-4-OH 2

CH

2 O--CH2 CHCH9 CH 2 0 0

CH

2 CH 2 NH (polyethvleneglycol diglycidyl ether) NH

CH

2 CH 2 CH? C= 2 (a portion of polyethylene- (a portion of polvezhhylrenei mine molecule) \aY mine molecule) N CH9 CHCH 2 0 -{CH 2

CH

2 0 H CH-CH 2

N

OH

2 OH OH- CH?

CH

2

CH

2 NH NH

CH

2

CH

2

OH

2 CH 2 9 The resulting gel product according to this invention may be used as deodorizer, but the present invention also includes within the ragne thereof such gel product when used for other utilities, e.g. used for antibacterial purpose.

The present invention is now illustrated by the follwing Examples which are illustrative of the gelation reaction with using an aqueous stabilised chlorine dioxide solution having a concentration of 50,000 ppm and which demonstrate the deodorization activity of acidic odor with use of the resulting gel typed deodorant composition.

Example 1 Each ingredient mentioned below was homogeneously mixed together in a suitable reactor and allowed to stand at ambient temperature (about 25 0 After the lapse of 30 minutes the gelation proceeded and after about one hour the reaction mixture was completely free of fluidity and produced a desired gel aqueous stabilized chlorine dioxide 10% by weigh solution at 50,000 ppm polyethylene-imine of molecular 2% by weighweight 70,000 polyethylenglycol diglycidyl ether of 1.5% by weic molecular weight 490 t t ght water 86,5% by weight 10 Example 2 Each ingredient mentioned below was uniformly mixed together and allowed to stand at ambient temperature (about 25 0 After the lapse of 10 minutes the gelation proceeded and after about 20 minutes the reaction mixture entirely lost its fluidity and produced a desired gel.

aqueous stabilised chlorine lioxide 10% by weight solution at 50,000 ppm polyethylene-imine of molecular 8% by weight weight 70,000 polyglycerol polyglycidyl ether of by weight molecular weight 742 (3 epoxide groups per molecule) water 79% by weight Example 3 Each component mentioned below was uniformly admixed together and allowed to stand at ambient temperature (about 25 0 After the lapse of 2 to 3 minutes, the gelation occurred and after about 7 minutes no fluidity was found in the reaction mixture and a desired gel was obtained.

aqueous stabilised chlorine dioxide 10% by weight solution at 50,000 ppm polyethylene-imine of molecular 20% by weight weight 20,000 11 polypropylene glycol diglycidyl 10 by weight ether of molecular weight 304 water 60 by weight Example 4 Each ingredient mentioned below was uniformly mixed together and allowed to stand at ambient temperature (about 25 0 After the lapse of 10 minutes the gelation of the reaction mixture took place and after about minutes no fluidity was found in the reaction mixture and a desired gel product was obtained.

aqueous stabilised chlorine dioxide 30% by weight solution at 50,000 ppm polyethylene-imine of molecular 5% by weight weight 100,000 polyethylene glycol diglycidyl ether of 2.5% by weight molecular weight 490 water 62.5% b- weight Example Each component mentioned below was throughly admixed together and allowed to stand at ambient temperature (about 25 0 After the lapse of 10 minutes, the gelation of the reaction mixture proceeded and after about minutes the reaction mixture lost its fluidity perfectly and there was afforded a desired gel product.

aqueous stabilised chlorine dioxide 87.5% by weight solution at 50,000 ppm polyethylene-imine of molecular 10% by weight weight 100,000 polyethylene glycol diglycidyl ether of 2.5% by weight molecular weight 490 water 0% by weight Example 6 Each component mentioned below was uniformly mixed together and allowed to stand at ambient temperature (about 0 After the lapse c 10 minutes, the gelation of the reaction mixture occurred and after about 30 minutes, the reaction mixture lost entirely its fluidity and there was obtained a desired gel product.

aqueous stabilised chlorine dioxide 2% by weight solution at 50,000 ppm polyethylene-imine of molecular 20% by weight weight 10,000 polyethylene glycol diglycidyl ether of 10% by weight molecular weight 490 water 68% by weight Example 7 Now the gel products obtained according to Examples 1 to 6 respectively were used for the deodorization test against acidic malodor gases, methylmercaptan and hydrogen V- .A

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i M sulfide.

The deodorization test was carried out according to the known head space method and there was used a 500 m2 conical flask fitted with a plug at the top thereof, thrcagh which two glass tubes having cocks and (b) were passed.

The test procedure employed and the test result obtained were as follows: Test procedure i) A gel sample (1 g) in a cubic form was hung on a hook located on the plug within the flask. Now the cocks ana were being closed.

ii) The cock was opened, the flask subjected to reduced pressure of about 3 mm Hg by a vacuum pump and l, then the cock closed.

iii) A gas collecting bag, i.e. Tedlar* bag into which a concentration-adjusted gas (methylmercaptan 45 ppm; hydrogen sulfide 500 ppm) was charged was connected to a gas introduction part upstream of the cock on the 2C plug. The cock was opened to introduce the malodor gas into the flask and then the cock closed and the Tedlar be removed from the introduction part.

*Tedlar is a trade name of polyvinyl fluoride.

iv) After the lapse of predetermined period, the cock was opened. Then odor gas concentration within the 14 flask was determined by means of Kitagawa typed detecting tube which had been connected to the rubber tube positioned at the end of the cock The detector then started to suck up the malodor gas optionally present in the flask preceding to the opening of the cock (a) Test results i) Methylmercaptan (ppm) Time 0.5 hr 2 hr 4 hr 6 hr Blank figure 45 42 40 37 Example 1 13 5 1 *ND Example 2 13 6 1 ND Example 3 15 5 1 ND Example 4 3 0.8 ND ND Example 5 ND ND ND ND Example 6 25 12 7 1 The gel sample prepared 15 6 1 NE from -Ltmple 1 was allowed to stand at ambient temperature (25 to 30 0 C) for a period of 6 months and the resultant aged product used for this test.

ND means not detected ii) Hydrogen sulfide (ppm) Time 0.5 hr 1 hr 2 hr Blank figure 500 500 460 Example 1 10 ND ND Example 2 10 ND ND Example 3 9 ND ND Example 4 4 ND ND Example 5 ND ND ND Example 6 150 45 Trace The gel sample prepared 10 ND ND from Exa:tple 1 was allowed to stand at ambient temperature (25 to 30 0 C) for a period of 6 months and the resultant aged product used for this test.

INDUSTRIAL UTILIZATION FIELD From the results of L. series of deodorization tests as mentioned above, it is clear that the gel-formed deodorant composition according to this invention is very effective for decdorization against acidic odor-generating substances such as hydrogen sulfide and methylmercaptan and further that even the gel product which had been allowed to stand at ambient temperature (25 to 30 0 C) for a period of 6 months showed no reduction in deodorization activity, namely had an excellent storage-stability. Accordingly, the gel-formed deodorant composition according to this invention can be used usefully to deodorize acidic malodors 16 generating from sulfur-containing compounds, which are evolved in wide-spread fields ranging from the industrial world to standard households, and is stable for a prolonged period of time because of its solid gel form as well as very easy to handle including the time of exchanging the deodorizer for another.

Claims (4)

1. A deodorant composition in the form of a gel containing chlorine dioxide, which composition is prepared by gelling an aqueous solution of stabilised chlorine dioxide with from 1 to 25% by weight of a polyethylene-imine having a molecular weight of from 10,000 to 100,000 and from 0.5 to by weight of an epoxide crosslink ng agent.

2. A deodorant composition as claimed in claim 1, wherein the polyethylene-imine has a molecular weight of from 20,000 to 70,000, and the epoxide deod, "izer is selected from the group consisting of ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, polyglycerol polyglycidyl ether, glycerol polyglycidyl ether and diglycerol polyglycidyl ether.

3. A deodorant composition substantially as herein described with reference to any one of Examples 1-6. :I DATED this 31st day of May 1993 .2a AIKOH CO., LTD. By their Patent Attorneys CULLEN CO. ABSTRACT This invention provides a deodorant 'omposition in the form of gel containing chlorine diox which comprises a gel product obtained by gelling in aqueous solution of stabilised chlorine dioxide with the use of both a polyethylene-imide having a molecular weight of from 10,000 to 100,000 and an epoxide crosslinking agent. The gel typed deodorant composition according to this invention is effective for deodorizing sulfur-containing compounds, has a high strength because of its solid gel form and a long-term stability, and is easy to handle including the time of exchanging the deodorant compositon for another one. I I INTERNATIONAL SEARCH REPORT International Application No PCT/JP8 9 /0 12 I. CLASSIFICATION OF SUBJECT MATTER (if several classification symbols apply, Indicate According to International Patent Classification (IPC) or to both National Classification and IPC Int. C15 A61L9/01 II. FIELDS SEARCHED Minimum Documentation Searched Classificaton System Classification Symbols IPC A61L9/01 Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included in the Fields Searched a III. DOCUMENTS CONSIDERED TO BE RELEVANT 9 Category Citation of Document, 11 with indication, where appropriate, of the relevant passages 2 Relevant to Claim No. 13 Y JP, A, 57-22102 (Daimaru Kogyo Kaisha Ltd.) 1, 2 February 1982 (05. 02. 82), (Family: none) Y JP, A, 50-26784 (Asahi Chemical 1, 2 Industry Co., Ltd.), 19 March 1975 (19. 03. Page 3, lower left column, line 8 to page 4, upper right column (Family: none) Y JP, A, 62-19171 (Hoechst Gosei 1, 2 Kabushiki Kaisha), 27 January 1987 (27. 01. 87), Page 3, upper left column, 5th '.ine from the bottom to lower left column, 6th line from the bottom and page 4, upper left column, lines 4 to 17 (Family: none) Special categories of cited documents: later document published after the international filing date or document defining the general state of the art which is not priority date and not In conflict with the application but cited to considered to be of particular relevance understand the principle or theory underlying the invention earlier document but published on or after the international document of particular relevance: the claimed invention cannot filing date be considered novel or cannot be considered to involve an inventive step document which may throw doubts n priority claims) or Y document of particular reevance thelamednvention canno which is cited to establish the publication date of another Y document of particular relevance the claimed nvention cannot citation or other special reason (as specified) be considered to involve an inventive step when the document is combined with one or more other such documents, such document referring to an oral disclosure, use. exhibition or combination being obvious to a person skilled in the art other means document member of the same patent family document published prior to the international filing date but later than the priority date claimed IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report February 19, 1990 (19. 02. 90) March 5, 1990 (05. 03. International Searching Authority Signature of Authorized Officer Japanese Patent Office Form PCT/ISA/210 (second sheet) (January 1985) I ~mmffimgPCT/JP 8 9/ 01 2159 Int. Cts A6 1 L9/01i IPC A6 1L9/0 I Y ,JP, A. 5 7-2 2 10 1. 2 2A~. 19 82 05. 0 2. 8 2) (7-7 L) 2 7. 1 A. 1 98 7 27. 0 1. 8 7), X 3 A L40iT 5 ff'- t:T 41T 6 ffAEF9

4 A F-4 4 B:f(7 z9- X 19.02.90CD 050390 El (N 0 =P F (ISA/JP) wmoz;bma WM: 93M I4,C 7 13 10 VgAPCT/lSA/210(W 2 91D)