Polyamide moulding composition and moulded article made from this moulding composition

Abstract

The present invention refers to a polyamide moulding composition consisting of the following components: a) 45 to 75% by weight of at least one partially crystalline polyamide consisting of at least one diamine and at least one aromatic dicarboxylic acid, whereupon the at least one diamine has 4 to 18 carbon atoms and is selected from a group of diamines consisting of linear aliphatic diamines, branched aliphatic diamines and cycloaliphatic diamines, b) 5 to 20% by weight of at least one fibrous reinforcing agent, c) 10 to 40% by weight of at least one non-sized filler which is different from the fibrous reinforcing agent in b), d) 0 to 10% by weight of a at least one additive, with the proviso that the component b) and c) add up to 25 to 45% by weight and the entirety of components a) to d) add up to 100% by weight. Moreover, the present invention refers to a moulded article producible from this moulding composition.

Claims

1. A polyamide moulding composition consisting of the following components: a) 50 to 75% by weight of at least one partially crystalline polyamide consisting of at least one diamine and at least one aromatic dicarboxylic acid, wherein the at least one diamine has 4 to 18 carbon atoms and is selected from the group consisting of linear aliphatic diamines, branched aliphatic diamines, and cycloaliphatic diamines, b) 5 to 20% by weight of at least one fibrous reinforcing agent, c) 10 to 40% by weight of at least one non-sized filler which is different from the fibrous reinforcing agent in b), and wherein the at least one non-sized filler is selected from the group consisting of milled glass fibres, milled carbon fibres, glass flakes, wollastonite, mica, phyllosilicates, and mixtures thereof, or whiskers, or is a mixture of at least one non-sized filler selected from the group consisting of milled glass fibres, milted carbon fibres, glass flakes, wollastonite, mica, phyllosilicates, and mixtures thereof; and whiskers, and d) 0 to 6% by weight of at least one additive, with the proviso that components b) and c) add up to 25 to 45% by weight and the entirety of components (a) to (d) adds up to 100% by weight, wherein the moulding compositions a condensable outgassing resulting in a haze of a maximum of 10%, measured by determining the haze on a glass plate after a thermal treatment of pellets of the rob/amide moulding composition at 200 C. for a period of 8 hours.

2. The moulding composition of claim 1, wherein the moulding composition has a deflection temperature under load (HDT (A)) according to ISO 75 of at least 190 C.

3. The moulding composition of claim 1, wherein the moulding composition has a condensable outgassing resulting in a haze of maximum of 7%.

4. The moulding composition of claim 1, wherein the moulding composition has a deflection temperature under load (HDT (A)) according to ISO 75 of at least 190 C. and a condensable outgassing of a maximum of 10%.

5. The moulding composition of claim 1, wherein the at least one dicarboxylic acid of the partially crystalline polyamide selected from the group consisting of terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and mixtures thereof.

6. The moulding composition of claim 1, wherein the at least one partially crystalline polyamide is selected from the group consisting of PA 6T/6I, PA 10T/6T, PA 10T/6T/10I/6I, and mixtures or blends thereof, in an amount of 50 to 69.95% by weight.

7. The moulding composition of claim 1, wherein the at least one fibrous reinforcing agent are glass fibres in, an amount of 5 to 15% by weight.

8. The moulding composition of claim 1, wherein the at least one non-sized filler is comprised in an amount of 15 to 35% by weight.

9. The moulding composition of claim 1, wherein components b) and c) add up to 30 to 44% by weight.

10. The moulding composition of claim 1, wherein the at least one additive is selected from the group consisting of inorganic stabilisers, organic stabilisers, lubricants, colouring- and marking materials, inorganic pigments, organic pigments, IR absorbers, antistatic agents, antiblocking agents, crystal-growth inhibitors, nucleating agents, condensation catalysts, chain extenders, defoamers, chain-lengthening additives, conductivity additives, carbon black, graphite, carbon nanotubes, mould-release agents, separating agents, flame retardants, non-halogen-containing flame retardants, anti-dripping-agents, impact modifiers, optical brighteners, photochromic additives, metallic pigments, metal coated particles, and mixtures thereof; and wherein the composition comprises the at least one additive in an amount of 0.05 to 6% by weight.

11. A moulded article produced from the moulding composition of claim 1.

12. The moulded article of claim 11, wherein the article is a lamp housing, lamp extension, lamp reflector, lamp socket, or a lamp plug socket.

Description

EXAMPLES

(1) For the preparation of the polyamide moulding compositions the following materials were used (s. Table 1):

(2) TABLE-US-00001 TABLE 1 Component Description Trade Name Producer PA 6I/6T polyamide 6T/6I (70/30 mol-%) made of EMS-CHEMIE AG, hexamethylendiamine, terephthalic acid Switzerland and isophthalic acid RV* 1.56, melting point 325 C. PA 6T/66 polyamide 6T/66 (52/48 mol-%) made of EMS-CHEMIE AG, hexamethylendiamine, terephthalic acid Switzerland and isophthalic acid RV* 1.72, melting point 310 C. PA 6 polyamide 6 made of -caproclactam 1013B Ube Industries, Japan RV** 2.5, melting point 222 C. PA 66 polyamide 66 made of Leona 1200 Asahi Chemical Industry, hexamethylendiamine and adipic acid Japan RV** 2.6, melting point 260 C. CuI copper (I) iodide, purity at least 98%, Junsei Chemical Co., Ltd, CAS-No. 7681-65-4 Japan KI potassium iodide, purity at least 98%, Junsei Chemical Co., Ltd, CAS-No. 7681-11-0 Japan chopped glass length 3 mm, diameter 11 m CS3J-260 Nitto Boseki Co., Ltd., fiber Japan milled glass fiber length 70 m, diameter 10.5 m, no sizing PF70E-001 Nitto Boseki Co., Ltd., Japan wollastonite needle shape, aspect ratio 15:1, SH-600 Kinsei Matec Co., Ltd, average (D.sub.50) particle size 11 m, Japan CAS-No. 013983-17-0 RV* relative viscosity, measured on a solution made of 0.5 g polyamide in 100 ml m-cresol at 20 C. RV** relative viscosity, measured on a solution made of 1.0 g polyamide in 100 ml sulfuric acid (96%) at 20 C.

(3) Production of polyamide moulding composition of example 1:

(4) The dried pellets of the partially crystalline polyamide 6T/6I (component a)) and a dry blend of components c) and d) were metered separately via gravimetric metering scales into the intake. Component b) was metered via a side feeder 4 cylinders bevor the die into the melt.

(5) The compounding is performed on a twin-screw extruder from Toshiba Machine Co., Ltd. Modell TEM-37BS at a set cylinder temperature of 80 C. for the first cylinder and 325 to 340 C. for the remaining cylinders. Degassing was performed to the atmosphere before the nozzle. The revolution speed was 120 rpm and the throughput 10 kg/h. The strands were cooled down in a water bath at 85 C. and subsequently pelletized. The pellets were dried for 24 hours at 110 C. in vacuum (30 mbar) to a water content of less than 0.1 wt-%.

(6) Table 2 shows the results for the mechanical and the fogging properties of the inventive examples together with comparative examples.

(7) TABLE-US-00002 TABLE 2 Examples Comparative Examples Component Unit 1 2 3 4 5 6 polyamide 6T/6I wt.-% 59.87 59.87 69.87 polyamide 6T/66 wt.-% 59.87 polyamide 66 wt.-% 59.87 polyamide 6 wt.-% 59.87 chopped glass fibers wt.-% 10 10 30 10 10 10 milled glass fibers wt.-% 30 30 30 30 wollastonite wt.-% 30 CuI wt.-% 0.03 0.03 0.03 0.03 0.03 0.03 KI wt.-% 0.1 0.1 0.1 0.1 0.1 0.1 Tests flexural modulus MPa 9380 9300 10590 8340 7700 8010 HDT A (1.80 MPa) C. 232 217 284 263 241 196 Fogging haze % 2.1 4.1 13.8 39.7 35.3 34.2

(8) It is obvious from Table 2 that the inventive examples 1 and 2 have the lowest haze which means the best fogging properties. Example 1 differs from example 2 that milled glass fibers instead of wollastonite are used as fillers. The best fogging properties were determined for example 1 with milled glass fibers as filler. Also obvious from the comparative examples 4 to 6 is the importance of the selection of the right partially crystalline polyamide. Despite of the same combination of components b) and c) in same amounts only with a partially crystalline polyamide a) containing exclusively aromatic dicarboxylic acids as dicarboxylic acids the fogging requirements can be fulfilled.