Vulcanization composition having reduced allergenic potential, and elastomeric articles formed therewith
The present invention generally relates to vulcanization compositions used to vulcanize elastomeric articles, where the vulcanization compositions have reduced allergenic potential as compared to elastomeric articles formed using vulcanization compositions having non-fugitive accelerators. The present invention also relates to elastomeric articles formed using the vulcanization compositions. The invention further relates to methods for making a reduced-allergenicity vulcanization composition, and to methods for using the vulcanization compositions to vulcanize elastomeric articles.
1. A method for forming a vulcanization composition, the steps comprising:
providing a source of sulfur;
providing a single fugitive xanthate accelerator;
providing a metal oxide; and
mixing the source of sulfur, single fugitive xanthate accelerator, and metal oxide, where the method for forming the vulcanization composition does not include any additional compounds that function as accelerators for vulcanizing elastomers and does not include additional xanthate compounds.
2. The method of claim 1 , wherein the metal oxide is selected from the group consisting of zinc oxide, magnesium oxide, lead oxide, and combinations thereof.
3. The method of claim 1 , wherein the source of sulfur is selected from the group consisting of elemental sulfur and sulfur donors that have a low allergenic potential, and combinations thereof.
4. The method of claim 1 , wherein the single fugitive xanthate accelerator is selected from the group consisting of diisopropyl xanthogen polysulfide, dibutyl xanthogen disulfide, and diisopropyl xanthogen disulfide.
5. The method of claim 1 , wherein the source of sulfur is provided in a range from about 0.1 to about 5 parts by dry weight rubber, the single fugitive xanthate accelerator is provided in a range from about 0.1 to about 10 parts by dry weight rubber, and the metal oxide is provided in a range from about 0.1 to about 15 parts by dry weight rubber.
6. The method of claim 1 , wherein the single fugitive xanthate accelerator is diisopropyl xanthogen polysulfide and the metal oxide is zinc oxide.
7. A method of making a latex dispersion, comprising the steps of:
providing polychloroprene;
providing a source of sulfur;
providing diisopropyl xanthogen polysulfide;
providing a metal oxide; and
mixing the polychloroprene, the source of sulfur, the diisopropyl xanthogen polysulfide, and the metal oxide to form the latex dispersion, where the method for forming the latex dispersion does not include any additional compounds that function as accelerators for vulcanizing elastomers and does not include additional xanthate compounds.
8. The method of claim 7 , wherein the latex dispersion has a total solids content from about 20% to about 45% for forming a first elastomeric layer or base layer.
9. The method of claim 7 , wherein the latex dispersion has a total solids content from about 1% to about 20% for forming a second or subsequent elastomeric layer.
10. The method of claim 7 , further comprising the step of adding non-curing ingredients to the latex dispersion.
11. The method of claim 10 , wherein the non-curing ingredients include one or more of the following compounds: antioxidants, stabilizers, plasticizers, anti-ozone agents, pigments and fillers.
12. A method for preparing a reduced-allergenicity polychloroprene elastomeric article, comprising:
providing the latex dispersion made by the method of claim 7 ;
coating a former with the latex dispersion by coagulant dipping to form a first elastomeric layer; and
drying and vulcanizing the first elastomeric layer.
13. The method of claim 12 , further comprising:
coating the former coated with the first elastomeric layer with one or more latex dispersions to form multiple elastomeric layers each having a same or different composition as the first layer, wherein the multiple elastomeric layers are applied prior to drying and vulcanizing the first elastomeric layer.
14. The method of claim 12 , further comprising:
coating the former coated with the first elastomeric layer with a second latex dispersion to form a second elastomeric layer, wherein the second elastomeric layer is applied prior to drying and vulcanizing the first elastomeric layer.
15. The method of claim 14 , wherein the second elastomeric layer has the same composition as the first elastomeric layer.
16. The method of claim 14 , wherein the second elastomeric layer has a different composition from the first elastomeric layer.
17. The method of claim 16 , wherein the second elastomeric layer is formed from a latex dispersion further comprising a second polymer latex selected from the group consisting of natural rubber, polyurethane, polybutadiene, polychloroprene, nitrile rubber, block copolymers of styrene and butadiene, block copolymers of styrene and isoprene, and synthetic polyisoprene.