GB2339391A - Antibacterial articles made of plastics materials - Google Patents

Description

2339391 ARTICLES MADE OF PLASTICS NIATERIALS This invention relates to

articles made of plastics materials and more particularly to a toothbrush and like articles.

Many articles these days are made from plastics materials. It has been proposed, where the articles are used in circumstances where hygiene is very important, to treat the plastics materials prior to moulding, extrusion, etc. with an anti-bacterial agent which is adapted to inhibit growth and where possible kill bacteria which may find their way onto the surface of the finished article.

Another factor of plastics articles is that they basically have no real smell of their own. Any smell which they do have is a mild scent representative of the plastics materials in general and is not, generally aesthetically pleasing It has been proposed to scent the plastics article with a suitable aesthetic fracrrance so that it is more appealing to the user. Such a scented plastics could be very suitable for containers used to store food, especially those foods which have strong smell which could affect food stored adjacent thereto.

In the field of toothbrushes, there are two desirable requirements as far as the materials used to make them. Firstiv, there is a hvL),Iene requirement because the toothbrush is going to be placed in the mouth and the transport of any harmful bacteria into the mouth from outside is undesirable. It is also desirable that the toothbrushes should smell nice and this is particularly desirable in the case of children-s toothbrushes where it is sometimes difficult to persuade them to brush their teeth regularly.

The present invention seeks to provide an article of plastics material in which "he above problems are obviated or significantly reduced.

According to a first aspect of the invention there is provided an article of plastics material which comprises a plastics material to which has been added both an antibacterial azent and a fraerance.

It is believed that the combination of the fragrance and the antibacterial materials has a synergistic effect in that the fragrance assists the anti-bacterial materials in migrating to the surface and thus makes more efficient use of the anti-bacterial materials.

If necessary, the materials concerned may be chosen specifically to enhance this effect.

For example, a scented oil such as coconut. peppermint or lavender oil may 'be used as a carrier for the anti-bacterial agent in the plastics masterbatch.

The firacrrance may be chosen to have a life related to the useful life of the plasti ics article either in relation to the life of the article or to the life of the anti-bacterial a(Tent.

Where the article is a toothbrush, the life of the fragrance may be related to the use of the brush and/or the life of anti-bacterial agent or both.

The fracyrance used may follow the colourincy of the toothbrush or other article.

C, C) The invention will now be described in Rreater detail, by way of example.

In the following discussion, the invention is applied to the manufacture of toothbrush handles. Basically, toothbrush handles are moulded from a plastics material, usually a polymer such as poly ropylene. During the production of the melt prior to the I P moulding operation, the plastics material is mixed With a colouring agent which provides the toothbrushes with their various distinctive colours which enables persons using the brushes to differentiate between them.

In accordance with an embodiment of the present invention, during the preparation of the plastics material, both an anti-bacterial agent and a fracyrance producing 0 agent are added to the plastics mix so that they are incorporated in the polymer matrix.

Suitable anti-bacterial auents include triclosan, zinc oxide, silver zeolyte and quaternary amalonium compounds. As for the fragrance, there are many fragrances which are suitable for imparting fragrance to plastics matenials and any of these can be used. The fragrances come in a number of different forms such as liquid, solid pellet or dust. One 210 particularly successful example uses solid pellets incorporated via a plastics master batch carrier such as that sold under the trade name Polviff by IFF Ltd.

The effect of the fraarance is to 2ive the effect of freshness to the toothbrush and to provide an indication that, due to the 'fragrance/antibacterial make up of the plastics material, the anti-bacterial effect is present.

It is even possible to use a fragrance which is associated with the colour of the toothbrush handle, viz: lemon for yellow brushes, orange for orange brushes; strawberry or raspberry for red brushes and so on.

Because the anti-bacterial a2ents and the fra2rances are located in the polymer matrix, they can migrate to the surface of an article moulded from the polymer and impart 3, 0 both anti-bacterial properties and fragrance to the surface.

Both the anti-bacterial aLyents and the frap-rances have a generally known life which depends to an extent on the relative concentration of the agents mixed in with the 3 plastics material. Thus it can be arranged that the fragrance will expire after a period of time during which the toothbrush is considered to be usable, for example, three months. The anti-bacterial agent may be chosen in a concentration to follow suit although it is desirable for the anti- bacterial agent to last longer than the fragrance so as to ensure that it can be effectively guaranteed that the anti-bacterial agent is still working until the last of the fragrance has dissipated.

Of course, it will be appreciated that the longevity of the various fragrances and anti-bacterial a2ents is not an exact matter and the indications as to when the toothbrush has past its useful life can vary over a period.

In any event, the actual life of the toothbrush will not be of a set period as such but will depend on how the brush is used and also on how often It is used. It therefore follows that any indicator of useful brush life based on the above is at best an approximation.

Two examples of a suitable mix for carrying out the invention will now be given- Example I

To make polypropylene toothbrush handles a batch of materials is produced havin2 the followin,2 constituents in %wel2ht-- Polypropylene homopolymer 87 1.0 Fraszrance freshmint Polyiff masterbatch 10 Anti-bacterial masterbatch (triclosan based) 2 Colour masterbatch I The above constituents were placed in a mixing drum and tumble mixed 'for a minimum of ten minutes before being supplied to a plastics moulding machine for mouldin2 the handles.

Example 2

To make rubber toothbrushes inserts a batch of materials is produced having "he foilowinu constituents in '1,owe;c_,ht-- 4 Thermoplastic elastomer (Kraiburg) 85 Fragrance freshmint Polyiff masterbatch 10 Anti-bacterial masterbatch (triclosan based) 2 Colour masterbatch, 3 The above constituents were placed in a mixing drum and tumble mixed for a minimum of ten minutes before being supplied to a plastics moulding machine for moulding the inserts.

The selection of the proportion of fragrance can be determined empirically to obtain the desired fraarance level and the desired anti-bacterial level can be determined by testing to achieve "zones of inhibition" on the finished toothbrush.

While the above described embodiment has related to the construction of toothbrush handles, it will be understood that the invention can equally well be applied to other articles. Amon2st suitable articles for production in accordance with the invention are hair brushes, children's toys and food containers.

Claims (11)

1. CLAINTIS:

   I. An article of plastics material comprising a plastics material to which has been added both an anti-bacterial agent and a fraarance.
2. 2. An article as claimed in claim 1, wherein a firaarance is used which has a life related to the usefiil life of the plastics article in relation to the life of the article.
3. J. An article as claimed in claim 1, wherein a fragrance is used which has a life related to the usefW life of the plastics article in relation to the life of the anti-bacterial agent.
4. 4 An arlicle as claimed in any preceding claim, wherein the article is a toothbrush.
5. 5. An article as claimed in claim 4, wherein the fragrance used has a life related to the expected life of the toothbrush.
6. 6. An article as claimed in any preceding claim, wherein the fragrance used follows the colouring of the article.
7. 7. An article of plastics material as claimed in claim I and substantially as described herein.
8. S. An article as claimed in any preceding claim wherein the antibacterial agent is triclosan.
9. 9. An article as claimed in anv precedincr claim wherein the fragrance is provided in the form of a scented carrier oil.

   0
10. 10. An article as claimed in any preceding claim, the article containing relative concentrations of anti-bacterial activity and fragrancle so that the anti- bacterial agent continues to work at least until the fraQrance has dissipated.
11. 11. An article as claimed in any preceding claim wherein the plastics material comprises polypropylene.

    :.5 1'. Use of a fra!arance as a means of indicating the period to expiry of the expected life of an article as claimed in any preceding claim.