AU627037B2 - Luminous condom - Google Patents

Description

I

LUMINOUS CONDOM

This invention relates to luminous latex articles and especially to condoms.

The term "luminous" used in this specification includes phosphorescent and fluorescent products. Articles in accordance with this invention preferably emit light for a period of at least a few minutes after exposure to light. Che i luminescent products which may be toxic are not preferred.

According to the first aspect of the present invention a process for making a luminous condom comprises the steps of: mixing a latex composition and a non-toxic luminous compound; immersing a mould in the mixture; withdrawing the mould to leave a coating of the mixture thereon; and curing the coating to form a luminous condom.

According to a preferred aspect of the invention the process includes the step of immersing the mould and coating of luminous latex composition in a substantially unfilled latex composition prior to curing. In alternative embodiments of the invention the luminous latex composition may be disposed between inner and outer layers of unfilled latex. This serves to minimise any physiological effects due to the constituents of the luminous latex.

The mould may preferably be immersed to a first depth in the luminous latex mixture or compound and then immersed to a greater depth in the unfilled latex. This ensures that the outer surface of the condom is sealed by the unfilled latex.

Preferred latices include medium modulus, prevulcanised natural rubber latices such as are used for manufacture of dipped goods. __Z- The luminous composition may be selected from the many luminous compounds which are available. Mixtures of such compounds may be employed. The composition is preferably non toxic and physiologically inert. Zinc sulphide based compositions are especially preferred, particularly zinc sulphide - copper containing compositions. For example the composition sold under the trade mark LUMILUX (Hoechst AC) especially LUMILUX N have been found to be particularly effective. The latter compositions exhibit yellow-green phosphorescence when stimulated with short wave daylight or artificial light.

Chemiluminescent or other self energising luminous compounds are not preferred on account of their toxicity and difficulty of incorporation into the latices without impairing the strength of the latter. Cadmium compounds which may be toxic are not preferred. Moreover luminescent coatings which may be applied to the exterior of a conventional condom are similarly dangerous and may not be employed.

The luminous composition may be provided as a powder or suspension in a carrying fluid. Particle sizes of 10 - 60 microns, especially 10 - 50 microns have been found to be suitable. Smaller particle sizes are particularly preferred in manufacture of condoms provided that the luminescent properties are not impaired in order to provide a smooth surface.

Percentages given in this specification are by weight unless indicated otherwise.

One or more thickening agents may be employed to maintain the luminious compound in suspension in latex. Sedimentation of the luminous compound during manufacture greatly reduces the useful life of an uncured latex composition. Prolonged agitation to maintain solids in suspension is detremental to the rheological properties of the latex. The thickening agent is preferably non toxic, tasteless and odourless and does not adversely affect the photochemical properties of the composition. Methyl cellulose thickening agents, for example carboxylated methyl cellulose may be employed. Alternative thickeners include Karaya gum, polyacrylates, sodium alginate and others known to those skilled in the art.

The luminous composition may include one or more photosensitisers or promotors as necessary.

The luminous latex mixture may comprise a latex with 20% - 50% of the luminous composition, preferably 20% - 40% more preferably 30% - 40% of the composition.

A finishing agent, for example polydimethylsi loxane (for example DIMETHICONE Cll) may be used to enhance the external appearance of the product.

Colouring materials, flavourings, fillers or other additives may be employed as desired.

According to the second aspect of the invention we provide a luminous condom composed of a latex containing a filler consisting essentially of a particulate luminous compound.

The luminous compound which preferably comprises zinc sulphide or zinc sulphide promoted with copper as previously described preferably also incorporates a thickening agent to facilitate dispersion of the solid phase within the latex.

Preferred condoms incorporate a luminous latex comprising 20 - 50%. or preferably 20 - 40% especially 30 - 40% of the luminous compound.

Male or female condoms may be provided. A condom may have a simple conventional construction or may be ribbed or formed into other novelty shapes. The condoms may be entirely luminous or may be partially luminous, being formed in part of a composition in accordance with the first aspect of this invention and the remainder being formed from conventional non luminous latex. The shaped portions of the novelty condoms may be formed from the luminous composition. Condoms in accordance with this invention confer numerous advantages. In addition to their enhanced entertainment value, the correct application in unlit surroundings is facilitated. In addition the novelty or amusement value of the products may reduce resentment to their use encouraging protection against disease. Furthermore it is possible to see if the condom becomes removed during intercourse.

The invention is further described by means of example but not in any limitative sense.

Example 1

A mixture of LUMILUX N (4.0kg) with a particle size of 10 microns carboxymethyl cellulose (1% of a 5% aqueous solution ) and uncured latex (10kg, 60% solids) was compounded using a mechanical blender. Condoms were manufactured from the mixture using a conventional chain conveyor apparatus wherein glass moulds were dipped twice into a bath of the latex mixture, cured by infra-red radiation and a coating of silicone lubricant applied. The condoms were removed from the mould and exhibited prolonged phosphorescence after exitation.

Example 2

A mixture of LUMILUX N (2.0 kg 40 microns) and uncured latex (13kg, 60% solids) was compounded and moulded as described in Example 1. The resultant condom exhibited prolonged phosphorescence.

Example 3

A composition containing uncured prevulcanised natural latex (PREVUL 5396M, Vitaliquid Polymers Ltd. 50kg) LUMILUX N (50kg 40 microns) and carboxymethyl cellulose (1% of a 5% aqueous solution) was formed into condoms using a fully automated batch production machine. The glass formers were cleaned by dipping into dilute hydrochloric acid (1%), dipping into water and then dipping into a calcium nitrate solution. The formers were then dipped into a suspension containing powdered talc in methanol and then dried in an oven. The inorganic materials act as a parting agent. The formers were then dipped successively into the mixture of latex and luminescent compound and then into a clear latex to which no filler had been added. The formers were immersed in the unfilled latex to a greater depth than the immersion in the filled latex. After allowing the composition to set, auto beading using rotating brushes and drying, the products are removed from the formers by wet stripping. The condoms are leached in cold circulating water and dried.

The formers may be axially rotatable on swivels to facilitate beading, allowing the brushes to rotate around the circumference of the condom. Two rotating brushes may be employed.

Example 4

The procedure of Example 3 was repeated using a similar latex composition to which 0.03% of a heat sensitising agent had been added. The former was heated to 40° to 60°C. The products were worked up as described in Example 3.

Alternative manufacturing methods known to those skilled in the art may be employed, for example straight dipping, coagulant dipping, anode dipping and casting (Kaysam process).

Claims (18)

(a CLAIMS

1. A process for making a luminous condom comprising the steps of: mixing a latex composition and a non-toxic luminous compound; immersing a mould in the mixture; withdrawing the mould to leave a coating of the mixture thereon and curing the coating to form a luminous condom.

2. A process as claimed in claim 1, including the step of immersing the mould and coating of luminous latex in a substantially unfilled latex composition prior to curing.

3. A process as claimed in claim 2 wherein the mould is immersed to a first depth in the luminous latex mixture and then immersed to a greater depth in the unfilled latex.

4. A process as claimed in any preceding claim, wherein the luminous compound is selected from the group comprsing: zinc sulphide, zinc sulphide-copper.

5. A process as claimed in claim 4, wherein the luminous compound has a particle size of 10 - 60 microns.

6. A process as claimed in claim 5 wherein the particle size is 10 - 50 microns.

7. A process as claimed in any preceding claim, wherein the luminous mixture comprises 20 - 50% of luminous compound relative to the latex dry weight.

8. A process as claimed in claim 7 wherein the mixture comprises 20 - 40% of the luminous compound.

9. A process as claimed in claim 8 wherein the mixture comprises 30 - 40% of the luminous compound.

10. A process as claimed in any preceeding claim, wherein said mixture includes a thickening agent.

11. A process as claimed in claim 10 wherein the thickening agent is selected from the group comprising: carboxylated methyl cellulose, other methyl cellulose derivatives, Karaya gum, polyacrylate thickeners and sodium alginate.

12. A process as claimed in any preceding claim including the steps of: immersing a clean mould successively in:

1) calcium nitrate solution

2) a suspension of an inorganic parting agent

3) a luminous latex mixture

4) an unfilled latex mixture; curing the coating on the mould and removing the cured latex from the mould to provide a luminous condom.

13. A luminous condom composed of latex containing a filler consisting essentially of a particulate luminous compound.

14. A luminous condom as claimed in claim 12, having an outer layer of substantially unfilled latex.

15. A luminous condom as claimed in claim 13 or 14 wherein the luminous compound comprises zinc sulphide or zinc sulphide-copper.

16. A luminous compound as claimed in any of claims 13 to 15 wherein the luminous latex comprises 20 to 50% of the luminous compound.

17. A luminous condom as claimed in claim 16 wherein the luminous latex comprises 20 - 40% of the luminous compound.

18. A luminous condom as claimed in claim 17 wherein the luminous latex comprises 30 - 40% of the luminous compound.