Articles comprising a cationic polysaccharide and silica

Details Articles comprising a cationic polysaccharide and silica Articles comprising a cationic polysaccharide and silica

2002-09-12

2004-12-21

Juska, Cheryl A. (Department: 1771)

Surgery

Means and methods for collecting body fluids or waste material

Absorbent pad for external or internal application and...

C442S121000, C442S096000, C604S359000

Reexamination Certificate

active

06833487

ABSTRACT:

CROSS REFERENCE TO RELATED REFERENCES
This is a continuation of International Application PCT/US01/13160 with an International filing date of Apr. 24, 2001.
FIELD OF THE INVENTION
This invention relates to articles, such as disposable absorbent articles, comprising a cationic polysaccharide, preferably chitosan material, together with silica.
BACKGROUND OF THE INVENTION
Malodors may be present in the environment from numerous sources both animate and inanimate. Many products and articles are available which aim to avoid or minimize the detection of such odors. In particular, it is particularly desirable to provide odor control materials to address the malodors which are generated by the human body, or from bodily fluids such as perspiration, urine, faeces, menstrual fluids, vaginal fluids and the like.
Articles like absorbent articles for example are designed to be worn by humans to absorb bodily fluids, such as urine, menstrual fluid and perspiration, etc. Examples of absorbent articles include sanitary napkins, pantiliners, disposable diapers, incontinence pads, tampons, perspiration pads, nursing pads and the like.
In use, the absorbent articles are known to acquire a variety of compounds, for example volatile fatty acids (e.g. isovaleric acid), ammonia, amines (e.g. triethylamine), sulphur containing compounds (e.g. mercaptans, sulphides), alcohols, ketones and aldehydes (e.g., furaldehyde) which release unpleasant odors. These compounds may be present in the bodily fluid or may be developed by chemical reactions and/or any fluid degradation mechanisms once the bodily fluid is absorbed into the absorbent article like for example a feminine pad. In addition bodily fluids usually contain micro-organisms and/or enzymes that can also generate malodorous by products as a result of degradation mechanisms like putrefactive degradation, acid degradation, proteins degradation, fat degradation and the like. Unpleasant odors, which emanate from absorbent pads when in use, may make the wearer feel self-conscious.
Various odor control materials have been disclosed in the art to combat some of the unpleasant odors referred to above. Indeed solutions have been provided that use different technical approaches like masking, i.e., covering the odor with a perfume, or absorbing the odor already present in the bodily fluids and those generated after degradation or preventing the formation of the odor.
Most of the focus in the prior art is found on the odor absorption technology. Examples of these types of compounds include activated carbons, clays, zeolites, silicas, starches, cyclodextrine, ion exchange resins and various mixture thereof as for example described in EP-A-348 978, EP-A-510 619, WO 91/12029, WO 91/11977, WO 89/02698, and/or WO 91/12030. All of these types of odor controlling agents are believed to control odor by mechanisms whereby the malodorous compounds and their precursors are physically absorbed by the agents and thus such agents hinder the exit of the odor from articles like absorbent articles. However, such mechanisms are not completely effective as the formation of the odor itself is not prevented and thus odor detection is not completely avoided. Some of the focus in the prior art has also been on the use of antimicrobial agents, amongst which chitosan and chitin based materials have been listed. For example WO 99/32697 discloses that chitosan and chitin-based polymers exhibit increased antimicrobial activity when coated onto the surface of a hydrophobic material such as polypropylene.
Although these materials provide some control of odors associated with bodily fluids, there still exists a need of further improvement in terms of odor control over a wide range of malodorous compounds.
There is ongoing work in this direction as illustrated in WO 99/61079. For example WO 99/61079 discloses odor reduction for products such as disposable diapers and training pants, sanitary napkins and tampons by the use of triglycerides and polyglycosides to enhance the malodor absorption properties of compositions and substrates such as naturally occurring polymers like chitosan or alginates and synthetic polymers treated with surfactants.
But there is still a need for further solutions to improve odor control performance of articles like disposable absorbent articles, beside the primary focus of such articles, which remain the ability of such articles to absorb and retain fluid.
Accordingly it is an object of the present invention to provide articles, especially disposable absorbent articles, which deliver outstanding odor control over a broad spectrum of malodors. More particularly it is an object to provide this benefit without impairing on the fluid handling properties of such articles, like fluid absorption and fluid retention.
It has now been found that the above needs can be addressed by combining a cationic polysaccharide together with silica, as the odor control system for an article, preferably a disposable absorbent article.
It has surprisingly been found that the combination of silica and a cationic polysaccharide, preferably chitosan material, in an article, like an absorbent article, typically coming into contact with bodily fluids, results in a synergistic effect in terms of odor control. Indeed this combination gives more odor reduction than the odor reduction associated with the use of one of these two classes of ingredients alone at the same total level (either silica alone or the cationic polysaccharide alone) in an absorbent article contacted with bodily fluids. Furthermore it has been found that the addition of silica to a cationic polysaccharide like chitosan material also improves the fluid handling properties of chitosan material. Indeed the articles of the present invention, typically the disposable absorbent articles comprising silica on top of the cationic polysaccharide, namely chitosan material, deliver improved fluid absorption and fluid retention as compared to the same articles without any silica.
Actually the combination of a cationic polysaccharide with silica in an article herein allows combining odor control mechanisms by which the overall malodor detection is synergistically reduced or even prevented.
Without to be bound by any theory it is believed that cationic polysaccharides, preferably chitosan materials, provide odor control of malodorous components associated with bodily fluid by multiple mechanisms.
Firstly, the odor absorption and retention characteristics of polysaccharides are due to the presence in the polymer structure of ionisable cationic functional groups. These groups are usually ammonium groups, a high proportion of which are in the salt form when the polymer is dry but which undergo dissociation and salvation upon contact with bodily fluid. In the dissociated state, the polymer chain will have a series of functional groups attached to it which groups have the same electric charge (e.g., —NH
3
+ +
H
3
N—) and thus repel one another. This leads to expansion of the polymer structure, which, in turn permits further absorption of negatively charged odorous molecules. Importantly the odor absorption property of cationic polysaccharides, especially chitosan materials, is not linked to the particle size of the absorbed odorous molecules but to their electrostatic properties.
Secondly, the positively charged cationic groups of the polysaccharides will interact with negatively charged anionic functionalities present in bodily fluids, like the carboxylic groups of proteins or hydroxylic acid bearing entities like short chain acid (e.g., butyric acid). This will result in the formation of tri-dimensional net between cationic polysaccharides and such molecules with anionic groups (gelification of the bodily fluids). This gelification will entrap most odorous molecules (like lipids, acids) thereby controlling malodor.
Thirdly and more importantly the cationic polysaccharides especially the aminopolysaccharides (preferably the chitosan materials) are believed to act as antimicrobial agents. Indeed the polysaccharides with their positive

Affiliated with

Also associated with

Rating

Articles comprising a cationic polysaccharide and silica does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Articles comprising a cationic polysaccharide and silica, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Articles comprising a cationic polysaccharide and silica will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3283028