This technology is available from Temarex Corporation.
Title: HYPOALLERGENIC NATURAL RUBBER LATEX AND A PROCESS FOR MAKING SAME
Inventor(s):W. Schloman, D. McIntyre
Disclosure 286 U.S. Patent not yet issued
Users of natural rubber (NR) products have been developing hypersensitivity, including Type I allergenicity (a systemicor immediate allergic reaction), through contact not only experienced through the skin, but also as a result of air-borne particles that enter the respiratory system. Therefore, a process has been developed that yields NR essentially free of antigens (i.e. proteins) known to cause allergenicity.
Natural rubber is a preferred source of cis-1,4-polyisoprene and a major source of NR is the Hevea brasiliensis (Brazilian) tropical tree and an alternative commercial source of NR exists in the guayule shrub, which is native to North America.
The present invention treats NR to reduce protein levels that are substantially lower than those using known techniques.For example, a Hevea dipped film can yield 360 mcg of extractable protein per gram of dry rubber and a commercially available HDPNR (highly-deproteinized NR) latex produces dipped films with about 50 mcg while the present invention yields less than 20 mcg.Some of the remnant proteins of the present invention are introduced in the course of latex preparation from non-rubber ingredients, but all remnant proteins are essentially free of antigens known to cause allergenicity.
Latex sample proteins were analyzed for known Hevea antigen content using the Guthrie LEAP Latex ELISA (enzyme-linked immunosorbent assay) and a second set of tests employed using murine protein polyclonal antibodies prepared by injecting female Swiss Webster mice with rubber particle suspensions.The results support the objectives listed below.
The objectives of the present invention are (a) to provide a NR latex that is hypoallergenic to the extent that the latex is essentially free of known antigens that potentially will elicit immune responses in individuals, (b) purify naturally obtained rubber and make a latex therefrom that is hypoallergenic, (c) provide a cured dipped film of NR latex wherein the NR latex is hypoallergenic and (d) provide a hypoallergenic semi-synthetic latex.
The latices obtained from this invention are ideally suitable for use in the preparation of medical, industrial and consumer products such as foam rubber, coating compositions, emulsion paints, rubber dams, bandages,adhesives, binders, garden hoses, elastic on underwear, etc.and especially dipped goods such as gloves, condoms, tubing,balloons, rubber bands and the like.