Abstract:
PROBLEM TO BE SOLVED: To shorten cooling time of a dispersion or a liq. after deodorizing treatment, to prevent a film which brings adhesion, piling and/or clogging of an apparatus during cooling treatment from being formed in case of a polymer- contg. dispersion and to simplify simultaneously a complicated structure of the apparatus. SOLUTION: Steam is passed through a dispersion or a liq. to be cooled and held in a treating container 1 and the dispersion or the liq. is whipped as the result (a) and this air bubble is discharged from the top part of the treating container 1 and it is fed into a vacuum separating container 4 through a nozzle and the air bubble is exploded during it (b) and steam formed from the air bubble is condensed by means of a heat exchanger 3 and volatile org. components are simultaneously removed (c) and exploded air bubble is returned to the container (d) and the processes (a) to (d) are performed until the dispersion or the liq. is deodorized to a required extent.
Abstract:
The present invention relates to a method for producing a polymer dispersion by radical polymerization of an aqueous monomer emulsion, characterized in that the monomer emulsion is produced continuously in accordance with consumption. 00000
Abstract:
processo para produção continua de elastomeros de poliuretano processáveis termoplasticamente, e, uso de elastômeros de poliuretano termoplásticos. a invenção está relacionada a método para a produção contínua de elastômeros de poliuretano termoplasticamente processáveis e com homogeneidade melhorada, pelo qual um poliisocianato (a), um composto (b) com uma média de pelo menos 1,8 e de no máximo 3,0 átomos de hidrogénio com atividade zerewitinoff, um peso molecular médio de 450 g/mol a 5000 g!mol, em uma proporção de 1 a 80 % equivalentes, em relação ao conteúdo de grupos isocianato no poliisocianato (a), um extensor de cadeia (c), com uma média de pelo menos 1,8 e de no máximo 3,0 átomos de hidrogênio com atividade zerewitinoff por molécula, um peso molecular numérico médio de 60 g!mol a 400 g/mol, em uma proporção de 12 a 99 % equivalentes, em relação ao conteúdo de grupos isocianato do poliisocianato (a), o a 30 % em peso de catalisadores, em relação à quantidade total de elastômeros de poliuretano e outros adjuntos e aditivos (d), em uma relação molar nco:oh de 0,9:1 a 1,2:1 do poliisocianato (a) para o total do composto (b), do extensor de cadeia (c) e dos outros adjuntos e aditivos, são alimentados a uma extrusora de duplo-parafuso auto-limpante, operada com uma alta velocidade de arrasto, sendo a mistura então descarregada da extrusora de duplo-parafuso auto-limpante para um dispositivo adicional para reação, caracterizado pelo fato de que na extrusora de duplo-parafuso auto- limpante, são ajustadas velocidades de arrasto acima de 6000 s^ -1^ e tempos de residência na faixa de 1 a 20 segundos.
Abstract:
A process is described for effectively reducing the residual monomer content of an aqueous polymer dispersion by aftertreatment at atmospheric pressure or above with an initiator system comprising a) a hydroperoxide, hydrogen peroxide or a peracid, and b) an alpha-hydroxy carboxylic acid, such as tartaric acid, or with a salt thereof.
Abstract:
A method for cooling dispersions or liquids (D/L) after a deodorising process comprising (a) passing steam through the D/L in a boiler (1), causing it to foam, (b) taking the foam from the top of the boiler into an evacuated separator (4) through a jet (5) and thus breaking the foam, (c) condensing the water vapour from the foam in a heat exchanger (8) and removing organic volatiles, and (d) returning the broken foam to (1). This process is continued until the D/L is deodorised to the required extent, then the hot D/L is cooled by transferring it from the bottom of (1) to the evacuated separator (4) via jet (5), the water vapour produced is condensed in (8) as before, and the cooled D/L is taken off at the bottom of (4).
Abstract:
A method for cooling dispersions or liquids (D/L) after a deodorising process comprising (a) passing steam through the D/L in a boiler (1), causing it to foam, (b) taking the foam from the top of the boiler into an evacuated separator (4) through a jet (5) and thus breaking the foam, (c) condensing the water vapour from the foam in a heat exchanger (8) and removing organic volatiles, and (d) returning the broken foam to (1). This process is continued until the D/L is deodorised to the required extent, then the hot D/L is cooled by transferring it from the bottom of (1) to the evacuated separator (4) via jet (5), the water vapour produced is condensed in (8) as before, and the cooled D/L is taken off at the bottom of (4).
Abstract:
A polymer dispersion is prepared by free radical polymerization of an aqueous monomer emulsion by a process in which the monomer emulsion is prepared continuously at the rate of consumption.
Abstract:
Method of reducing the residual monomer (I) content in a solution, mixture, melt, suspension or dispersion of a polymer produced by free radical polymerization (liquid system). The process involves adding a nucleophilic agent (II), which forms an adduct with (I) at the reaction temperature, in an amount of 0.5-5 mole (II) /mole (I). The novelty is that (II) is stirred gradually into the liquid system in a production reactor with a height/diameter ratio of 0.8-4 in a dosing time not less than the shortest possible mixing time.
Abstract:
A polymer dispersion is prepared by free radical polymerization of an aqueous monomer emulsion by a process in which the monomer emulsion is prepared continuously at the rate of consumption.
Abstract:
A polymer dispersion is prepared by free radical polymerization of an aqueous monomer emulsion by a process in which the monomer emulsion is prepared continuously at the rate of consumption.