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Method of producing synthetic latex Invention relates to a method of producing synthetic latex from rubber. The method comprises steps of: (a) emulsifying a binding substance containing rubber, which is dissolved in a suitable organic solvent, together with an aqueous surfactant solution to form an oil-in-water emulsion; (b) step-by-step reduction of content of solvent in the oil-in-water emulsion in two or more steps, resulting in formation of synthetic latex. Also described is a reactor with continuous mixing for removing the organic solvent from the oil-in-water emulsion, which contains rubber dissolved in the organic solvent. |
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Invention relates to nitrile rubber, method of its obtaining and products, obtained from it. Claimed nitrile rubber contains structure repeat units of, at least, one α,β- unsaturated nitrile and, at least, one conjugated diene, and has ion indicator in range 0-60 ppm×mole/g. Nitrile rubber is obtained by emulsion polymerisation. Obtained latex, which contains nitrile rubber, is subjected to coagulation, and then coagulated nitrile rubber is washed. Polymerisation is carried out in presence of, at least, one alkylthiolate. Before coagulation value of latex pH is set at level, at least, 6, and then is coagulated in presence of, at least, one magnesium salt. Temperature of latex before adding at least one salt of magnesium is set at value 45°C. Obtained nitrile rubber is applied for obtaining capable of vulcanisation mixtures, which contain claimed rubber, at least, one linking agent and, if necessary, additional target additives to rubbers. Capable of vulcanisation mixtures are vulcanised by casting with obtaining cast products. |
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Nitrile rubber contains repeating units of at least one α,β-unsaturated nitrile and at least one conjugated diene and has ionic index in the range of 7-26 ppm×mol/g. The nitrile rubber is obtained by emulsion polymerisation. The obtained latex, which contains nitrile rubber, is coagulated and the coagulated nitrile rubber is washed. Polymerisation is carried out in the presence of at least one alkylthiol. Before coagulation, the pH of the latex is set to at least 6, and coagulation is then carried out in the presence of at least one salt of a monovalent metal. The latex coagulation temperature ranges from 60 to 90°C and the washing temperature ranges from 50 to 90°C. The obtained nitrile rubber is used to obtain curable mixtures which contain said rubber and at least one cross-linking agent. The curable mixtures are cured by moulding to obtain moulded articles. |
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Method of extracting butadiene-nitrile rubber from latex Method of extracting butadiene-nitrile rubber from latex is carried out by feeding sodium sulphite or sodium bisulphite or sodium pyrosulphite in amount of 0.05-0.8 wt % per latex, into a stream of latex degassed beforehand, into which an antioxidant emulsion is also fed. Further, the stream of latex, containing sulphite, is directed into a coagulation apparatus into which aqueous sulphuric acid and an organic amine coagulant in form of a quaternary polymer ammonium salt are also simultaneously fed, said salt being selected from: polydimethyl diallyl ammonium chloride, a methacrylamide and dimethyl aminoethyl methacrylate hydrochloride copolymer, and polydiethyl aminoethyl methacrylate hydrochloride. The amount of the polymer ammonium salt varies from 0.2-0.5 wt %, per rubber, depending on content of leukanol content in latex in the range of 0.1-0.4 wt %, per rubber, at coagulation pH 3-6 and temperature 30-70°C. |
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Method of controlling process of extracting emulsion rubber from latex Rubber is extracted from latex continuously by mixing latex with a coagulant. Consumption of coagulant is varied depending on the given turbidity value of serum (primary serum), which is maintained by the amount of coagulant fed. The given turbidity value of primary serum is adjusted depending on the turbidity of the serum released (secondary serum) towards the minimum consumption of coagulant to obtain minimum turbidity of the released serum. |
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Method of emulsion polymerisation rubber stabilisation N (4-anilinophenyl)amide of alkenylsuccinic acid of general formula , where n=6-18 is used as a stabiliser of phenylenediamine type. The stabiliser is introduced into latex in amount 0.1-1.5 weight fractions per 100 weight fractions of rubber as aqueous alkaline liquor. While using the stabiliser of low content of ballast substance less than 3% and high content of fragments of phenylenediamine type, is suitable to be introduced into latex. |
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Process of preparing cationic latex with hollow polymeric particles Invention relates to preparing aqueous cationic latexes with hollow polymeric particles serving as multifunctional additives used when preparing polymer compositions, paintwork materials, coatings (including paper coatings), and in other applications as white pigment and filler reducing density of material and internal stresses arising during formation of coatings or polymer materials. Process comprises at least three following stages: (A) preparing functional core copolymer, (B) preparing particles with core-shell morphology, and (C) ionization of functional groups of core copolymer. All process stages are carried out as a series of consecutive transformations in the same reactor without discharge of intermediate products. As monomer containing functional groups in stage A, vinylbenzyl chloride is used, and stage C represents amination of vinylbenzyl chloride units with tertiary aliphatic amines, pyridine, or derivatives of the latter. |
Another patent 2513461.