| 摘要 |
Aqueous dispersions of rubber are prepared, with a small expenditure of power and without the preliminary step of forming of water-in-rubber dispersion, by masticating plasticized rubber with an aqueous paste of an organic colloid such as soap and an attrition agent, preferably a non-colloidal mineral powder employed as a rubber compounding ingredient such as whiting, slate dust, diatomaceous earth or the substance sold under the Registered Trade Mark "Silex." The dispersions may be diluted with water, which may contain compounding or vulcanizing ingredients in suspension, and may be employed for making rugs by causing fibres to adhere to a fabric foundation, proofing textiles, making compound fabrics or as sealing compositions. Example: 850 parts of reclaim rubber are plasticized in a mixing apparatus with 45 parts of a softener such as cumar, mineral rubber or gum rosin, and are added in mass or progressively to a masticating machine containing a thick paste comprising 160 parts of rosin soap, 700 parts of whiting and 350 parts of water; mastication is continued for 30 to 80 minutes at about 180 DEG F., water being added if required to maintain the consistency of the mass; the dispersion is diluted with 4000 parts of water to half of which 120 parts of gum tragacanth, 30 parts of sulphur, 50 parts of zinc oxide and 2 parts of a vulcanization ultra-accelerator may be added; alternatively these ingredients may be added in dry form to the diluted dispersion; small quantities of essential oils and preservatives such as ammonia and formaldehyde may be included in the composition. Specification 351,427 is referred to.ALSO:A rubber composition in the form of an aqueous dispersion which may be employed for proofing textiles, as an adhesive making compound fabrics or rugs, or as a sealing composition, comprises the following ingredients: reclaim rubber 43,4 per cent, softener such as cumar, mineral rubber, or gum rosin 2,3 per cent, rosin soap 8,19 per cent, whiting 35,8 per cent, zinc oxide 2,55 per cent, sulphur 1.53 per cent, water soluble gum such as gum tragacanth 6,13 per cent, vulcanization accelerator 0,10 per cent.
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