Polyamide moulding material on the basis of mixtures of transparent copolyamides and aliphatic homopolyamides for producing transparent moulded parts

摘要

Polyamide molding composition based on a mixture of transparent copolyamides, and semicrystalline, aliphatic polyamides, comprises (A) at least one transparent copolyamide made of (a) cycloaliphatic diamine comprising bis-(4-amino-3-methyl-cyclohexyl)-methane, bis-(4-amino-cyclohexyl)-methane, bis-(4-amino-3-ethyl-cyclohexyl)-methane and/or bis-(4-amino-3 ,5-dimethyl-cyclohexyl)-methane, and (b) an unbranched, aliphatic diamine and (c) at least one aliphatic and cycloaliphatic dicarboxylic acid (B1) at least one additional polyamide, and (C1) additives. Polyamide molding composition based on a mixture of transparent copolyamides, and semicrystalline, aliphatic polyamides for the production of transparent molded parts, comprises (A) 25-75 wt.% of at least one transparent copolyamide made of (a) 50-90 mole-% of cycloaliphatic diamine comprising bis-(4 - amino-3-methyl-cyclohexyl)-methane, bis-(4-amino-cyclohexyl)-methane, bis-(4-amino-3-ethyl-cyclohexyl)-methane and/or bis-(4-amino-3 ,5-dimethyl-cyclohexyl)-methane, and (b) 10-50 mole-% of an unbranched, aliphatic diamine with 9-14 carbon atoms or its mixtures, respectively based on the total amount of diamines and (c) at least one aliphatic and cycloaliphatic dicarboxylic acid with 10-36 carbon atoms, (B1) 25-75 wt.% of at least one additional polyamide of the type PAXY1, where X and Y1 are 9-14, and (C1) 0-10 wt.% of additives comprising UV stabilizers, heat stabilizers, radical scavengers, processing aids, inclusion inhibitors, lubricants, demolding auxiliary substances, plasticizers, functional additives for influencing the optical properties, preferably the refractive index, impact modifiers, fillers and/or aggregates, optical brighteners and/or dyes. The components (A), (B1) and (C1) is 100 wt.%. Independent claims are also included for: (1) preparing the polyamide molding composition comprising preparing the polymer components (A) and (B1) in a pressure vessel with a pressure phase of 250-320[deg] C with a subsequent expansion at 250-320[deg] C and a subsequent degassing at 260-320[deg] C, discharging the polyamide molding composition in strand form, cooling, granulation and drying the granules, compounding the components (A), (B1), and optionally (C1) as granules and molds in an extruder at material temperatures of 220-350[deg] C to form a strand and cutting with suitable granulators into pellets, where additives, e.g. processing stabilizers, pigments, UV absorbers, heat stabilizers, flame retardants and other transparent polyamides during the compounding for the finishing of the molding composition; and (2) a molded part obtained from the polyamide molding composition by means of injection molding and injection-compression process at material temperatures of 230-320[deg] C, where the tool is adjusted with temperatures of 40-130[deg] C, and optionally the tool with temperatures of 40-130[deg] C applies an embossed print on the hot molded part, after filling the cavity.