Patent GB-439505-A (GB)
Title: Improvements in or relating to the production of artificial dispersions of or containing rubber
IPC: C08J3/205
Filed: 1934-06-08
Abstract: Aqueous dispersions of or containing rubber are obtained by incorporating easily fusible solid or adhesive semi-solid or mobile liquid rubber compounding ingredients which are soluble in rubber and substantially non-volatile at ordinary temperatures and posses a boiling point above 200 DEG  C., such as plasticizers, anti-oxidants, softeners and accelerators, by penetrative dissolution or diffusion into the rubber in such a manner as to soften the rubber without altering its nature and thus dispersing the soft unworked rubber mix in an aqueous medium by introducing water until inversion of phase occurs, in known manner.  Suitable materials which may thus be incorporated include fluid viscous or semi-solid accelerators or anti-agers of the aldehyde-amine type, e.g. acetaldehyde-aniline or aldol and a -naphthylamine; oleic acid and similar organic acids; pine-oil, cottonseed oil, mineral oils; and fatty acids, e.g. zinc laurate or lead oleate.  Less easily fusible ingredients, e.g. sulphur, accelerators such as zinc diethyl dithiocarbonate and thiuram sulphides or anti-oxidants such as phenylnaphthylamines may be dissolved in the above liquid or readily fusible compounds. Hydrophilic and/or colloidal materials, e.g. alkali or ammonium soaps, which are used to effect the dispersion may be introduced together with the compounding ingredients, or a parent substance therefor, e.g. a fatty acid may be so introduced and an agent necessary for the formation of the dispersing agent, e.g. ammonia or potash, then added by a diffusion process or by mixing an aqueous or alcoholic solution with the rubber mix.  According to an example, 250 gms. of thin purple cr<\>zepe in small pieces are added to 750 gms. of non-volatile mineral oil boiling above 200 DEG  C., and the mass frequently stirred at room temperature until a soft swollen mass is obtained.  This is placed in an internal mixer and 50 gms. oleic acid and 20 gms. powdered casein added and mixed.  Dilute ammonia (one vol. of 0.88 ammonia to 9 vols. water) is gradually added with reduction of temperature and mixing to obtain an aqueous dispersion. If the compounding ingredients are melted, the rubber should be raised in temperature before the materials are incorporated; with temperatures of the order of 150 DEG  C., an inert atmosphere e.g. of carbon dioxide or nitrogen may be used. The dispersions may be added to natural latex to produce as compounded latex having an higher proportion of rubber then natural latex, and a larger proportion of compounding ingredients may be added to the dispersion to treat the rubber in the natural latex.  Reference has been directed by the Comptroller to U.S.A. Specification 1,910,244.ALSO:Aqueous dispersions of or containing rubber are obtained by incorporating easily fusible solid or adhesive semi-solid or mobile liquid rubber compounding ingredients which are soluble in rubber and substantially nonvolatile at ordinary temperatures and posses a boiling point above 200 DEG  C., such as plasticizers, anti-oxidants, softeners and accelerators, by penetrative dissolution or diffusion into the rubber in such a manner as to soften the rubber without altering its nature and then dispersing the soft unworked rubber mix in an aqueous medium by introducing water until inversion of phase occurs, in known manner.  Suitable materials which may thus be incorporated include fluid viscous or semisolid accelerators or anti-agers of the aldehydeamine type, e.g. acetaldehyde-aniline or aldol- and a -naphthylamine; oleic acid and similar organic acids; pine-oil; cottonseed oil, mineral oils; and fatty acids, e.g. zinc laurate or lead oleate.  Less easily fusible ingredients, e.g. sulphur, accelerators such as zinc diethyl dithiocarbamate and thiuram sulphides or anti-oxidants such as phenylnaphthylamines may be dissolved in the above liquid or readily fusible compounds. Hydrophilic and/or colloidal materials, e.g. alkali or ammonium soaps, which are used to effect the dispersion may be introduced together with the compounding ingredients, or a parent substance therefor, e.g. a fatty acid may be so introduced and an agent necessary for the formation of the dispersing agent, e.g. ammonia or potash then added by a diffusion process or by mixing an aqueous or alcoholic solution with the rubber mix According to an example, 250 gms. of thin pale cr<\>gepe in small pieces are added to 750 gms. of non-volatile mineral oil boiling above 200 DEG  C., and the mass frequently stirred at room temperature until a soft swollen mass is obtained.  This is placed in an internal mixer and 50 gms. oleic acid and 20 gms. powdered casein added and mixed.  Dilute ammonia (one vol. of 0,88 ammonia to 9 vols. water) is gradually added with reduction of temperature and mixing to obtain an aqueous dispersion. If the compounding ingredients are melted, the rubber should be raised in temperature before the materials are incorporated: with temperatures of the order of 150 DEG  C., an inert atmosphere, e.g. of carbon dioxide or nitrogen may be used. The dispersions may be added to natural latex to produce a compounded latex having a higher proportion of rubber than natural latex, and a larger proportion of compounding ingredients may be added to the dispersion to treat the rubber in the natural latex.  Reference has been directed by the Comptroller to U.S.A. Specification 1,910,244.