Abstract: There is described a process for preparing a biodegradable polyester from an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid and a diol where in a first reaction step the aromatic acid is esterified with the diol, and in a second reaction step the aliphatic acid is added to the reaction mixture. Furthermore, there is described an apparatus for carrying out this process.

Abstract: A process for reducing the amount of hydroxyl-end-groups of a polyester, wherein the polyester is prepared from at least one dicarboxylic acid and at least one dihydroxy alcohol, and at least one additive selected from the group consisting of carboxylic acid anhydride and mono-isocyanate, and wherein the additive is added during a step of prepolycondensation and/or during a step of polycondensation and/or after a step of polycondensation.

Abstract: There is described a process for preparing a biodegradable polyester from an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid and a diol where in a first reaction step the aromatic acid is esterified with the diol, and in a second reaction step the aliphatic acid is added to the reaction mixture. Furthermore, there is described an apparatus for carrying out this process.

Abstract: The present application relates to a process for preparing polyesters comprising reacting a dicarboxylic acid with butanediol in the presence of a catalyst, wherein in the process an aluminosilicate is present, as well as the use of aluminosilicates in such a process.

Abstract: The application relates to a process for reducing the amount of hydroxyl-end-groups of polyesters, wherein the polyester is prepared from at least one dicarboxylic acid and at least one dihydroxy alcohol, and at least one additive selected from the group consisting of dicarboxylic acid anhydride and/or monoisocyanate is added during and/or after the process of preparing the polyester.

Abstract: A method is disclosed for producing polymers with a neutral color tone, wherein a blue and red dye are added before entry into the last polyreaction stage, wherein adjustment of a neutral color tone of the polymer, using a total dye concentration in the polymer of no more than 3 ppm and a proportion of the blue dye in the resulting dye mixture of at least 50% by weight, occurs through independent adjustment of a and b color values in the Lab color space by determination of a and b color values of the polymer without addition of dyes, establishment of the total dye concentration depending on the b-value shift to be achieved, establishment of the required mixture ratio of the colors red and blue depending on the a-value shift to be achieved, and metering of the established content of dye mixture into the reaction mixture.

Abstract: A method is disclosed for producing polymers with a neutral color tone in one or more reaction stages through independent adjustment of a and b color values in the Hunter l,a,b color space of the polymer, which comprises the steps of: (a) determining the a and b color values of the Hunter l,a,b color space of the polymer prior to any addition of a dye; (b) establishing a total dye concentration not exceeding 3 ppm for the polymer depending on the b color value to be achieved following a b value shift; (c) establishing a required dye mixture ratio of red and blue dyes for the polymer depending on the a color value to be achieved following an a value shift, where the proportion of the blue dye in the dye mixture is at least 50% by weight; and (d) following steps (b) and (c) metering into a reaction mixture for forming the polymer at a point before entry into the last polyreaction stage, the dye mixture having the total dye concentration as defined in step (b) and the required dye mixture ratio of the red and

Abstract: A safety cabinet has a plurality of walls defining a front open side and a pair of doors pivotal about respective horizontally spaced axes on the walls between a closed and an open position. Guides in the cabinet are each associated with a respective one of the doors, and respective links each have a front end connected to a respective one of the doors and a rear end shiftable front-to-back in a respective one of the guides. A connector extends between the rear ends of the links and shifts front-to-back with them. A closer is operatively engageable with the connector, and a spring applies bears on the closer to urge it against the connector for pushing same into the rear end position and closing the doors. An actuator normally holds the closer out of engagement with the connector during movement of same between the front and rear end positions.

Abstract: The invention relates to a method for treating vapours and condensates which arise during the production of polycondensates from bisphenols or high-value phenols by esterification and/or transesterification with alkyl or aryl esters of at least bivalent organic or inorganic acids. According to the invention, the treatment is carried out in a plurality of condensates and/or distillation columns which are connected in a step-by-step manner behind each other, each distillation column comprising a connected condensate. The dew point and the pressure in each condensate are adjusted such that in each step, monomers, oligomers or decomposition and transformation products are removed.

Abstract: The invention relates to a method for producing a granulate with a low acetaldehyde content and improved processing properties from a high-viscosity polyester melt, wherein the polyester melt strand is fragmented under water at the highest possible temperature, the accompanying water is separated from the granulate with the least possible cooling of the granulate, the low-water granulate obtained in this way is passed after removal of the water directly into a dealdehydisation container and the granulate in the dealdehydisation container is treated with a flow of rinsing air, plus a device for carrying out this method.

Abstract: The invention relates to a method for producing a granulate with a low acetaldehyde content and improved processing properties from a high-viscosity polyester melt, wherein the polyester melt strand is fragmented under water at the highest possible temperature, the accompanying water is separated from the granulate with the least possible cooling of the granulate, the low-water granulate obtained in this way is passed after removal of the water directly into a dealdehydisation container and the granulate in the dealdehydisation container is treated with a flow of rinsing air, plus a device for carrying out this method.

Abstract: Prior art terminals with operating buttons and a contact member movable against the force of a spring are relatively bulky and complex. It is proposed to provide a part of a curved leaf spring as the contact member having at least one aperture fitted in such a way above the conductor guide that an edge of the aperture acts as the contact member. This design also permits the contacting of thin conductors.