| 摘要 |
<p>#CMT# #/CMT# Polychloroprene-solid material exhibiting thixotropic properties, is claimed. #CMT# : #/CMT# Independent claims are also included for: (1) isolating and obtaining the above polychloroprene-solid material, comprising contacting aqueous polychloroprene-dispersion with a coagulating agent containing water vapor, where the polychloroprene-solid material is coagulated; (2) a vulcanizable mixture comprising at least one polychloroprene-solid material and least one crosslinking agent; (3) producing vulcanizate, based on at least one polychloroprene-solid material, comprising crosslinking the vulcanizable mixture; and (4) the vulcanizate based on at least one polychloroprene-solid material. #CMT#USE : #/CMT# The polychloroprene-solid material is useful for rubber applications. #CMT#ADVANTAGE : #/CMT# The polychloroprene-solid material exhibits improved shelf-life, flow behavior, high weathering- and ozone resistance, flame resistance, aging properties, resistance to oils as well as to chemicals, and improved mechanical properties including elastic properties and a high resistance to wear and tear. #CMT#INDUSTRIAL STANDARDS : #/CMT# Preferred Components: The property of thixotropy manifests that the melt viscosity measured as a Mooney viscosity of ML 1+4 at 100[deg] C, (according to ASTM D 1646) decreases during treating the polychloroprene solid material over a roller. #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Components: An aqueous solution of inorganic salts (coagulating agent), made of metals of the second and third main group of the Periodic Table, preferably calcium chloride, magnesium chloride, magnesium sulfate, aluminum chloride and/or aluminum sulfate is used as the coagulating agent solution. The coagulating agent comprises water vapor and the aqueous coagulating agent solution. The coagulating agent solution exhibits a coagulating agent-concentration of 1-60 wt.%, preferably 10-35 wt.%, based on the coagulating agent solution. The weight ratio of the water vapor is 80-1000 kg of water vapor/solid material (t) of the polychloroprene-dispersion, preferably 80-250 kg water vapor/solid material (t) of the polychloroprene-dispersion. The weight ratio of the coagulating agent is 10-40 kg/ solid material (t) of the polychloroprene-dispersion, preferably 10-25 kg coagulating agent/solid material (t) of the polychloroprene-dispersion. #CMT#POLYMERS : #/CMT# Preferred Components: The property of thixotropy manifests itself that solution viscosities of a solution of the polychloroprene-solid material decreases at mechanical force/shearing and reforms in a subsequent rest state. A structure degradation occurs in the polychloroprene-solid material under mechanical force/shearing and a structure reconstruction takes place in the subsequent rest state. The degradation or reconstruction of the solution viscosity of the solution of the polychloroprene-solid material occurs with respect to time. The solution viscosity is determined by adopting a Brook field viscosity-method. Preferred Method: The polychloroprene-solid material is obtainable from polychloroprene dispersion, by carrying out the emulsion polymerization at a polymerization temperature greater than 30[deg] C in the range of 35-50[deg] C, preferably 35-45[deg] C. The method includes separating the polychloroprene-solid material from the coagulating suspension. The polychloroprene-solid material is dewatered by a dewatering device, and the dewatered polychloroprene-solid material is dried by a drying device. The method includes adding additives and/or inert substances into the drying device containing the dewatered polychloroprene-solid material. The dried, dewatered, polychloroprene-solid material is cooled and granulated by carrying out underwater pelletization. The polychloroprene-dispersion prior to contacting with the coagulating agent containing water vapor, is diluted to a solids content of 38-45 wt.%, preferably 20-28 wt.%, based on the polychloroprene-dispersion. #CMT#EXAMPLE : #/CMT# Polychloroprene-dispersion (prepared by carrying out free radical emulsion polymerization at 40-45[deg] C using the component including (in parts by wt.): water (125), monomers (2-chloro-1,3-butadiene or a mixture of 2-chloro-1,3-butadiene and 2,3-dichlorobutadiene) (100), sodium salt of disproportionated abietic acid (3), potassium hydroxide (0.5), n-dodecyl mercaptan (0.2), and sodium salt of naphthalene sulfonic acid condensed with formaldehyde (0.5)) was pumped into a flow device or a coagulating device from a storage tank, and the polychloroprene-dispersion was diluted with water before being pumped into the flow- or the coagulating device, and the aqueous coagulating agent previously mixed with water vapor, was supplied to the flow- or the coagulating device from a further storage tank, and was contacted with the polychloroprene-dispersion through their recesses. Subsequently, the polychloroprene-dispersion was quantitatively precipitated in a precipitation tube of the flow- or the coagulating device.</p> |
