Composite plastic part with improved resistance to heat aging

Abstract

The present invention relates to a process for producing a plastic composite component (CC) in which a first fiber material (F1) is impregnated with a polyamide matrix polymer (PAM) to obtain a matrix composition (MC), to which a surface composition (SC) is applied, and a first plastic component (C1) is obtained. In a second step, a second plastic component (C2) is molded onto the first plastic component (C1), giving the plastic composite component (CC). The invention further relates to the plastic composite component (CC) obtainable by the process of the invention. The present invention further provides for the use of polyethyleneimine (PEI) for improving the impregnation of the first fiber material (F1) with the polyamide matrix polymer (PAM).

Claims

1. A plastic composite component, comprising i) a first plastic component comprising ia) a matrix composition comprising a polyamide matrix polymer and a first fiber material for reinforcement, and ib) a surface composition which comprises a polyamide surface polymer and a polyethyleneimine that improves thermal aging resistance of the plastic composite component and forms a surface of the first plastic component, wherein the matrix composition does not comprise any polyethyleneimine.

2. The plastic composite component according to claim 1, further comprising ii) a second plastic component which comprises a polyamide molding polymer and is molded onto the surface of the first plastic component.

3. The plastic composite component according to claim 1, wherein the polyethyleneimine has a weight-average molecular weight M.sub.w of from 600 to 300 000 g/mol.

4. The plastic composite component according to claim 1, wherein the polyethyleneimine comprises primary, secondary and tertiary amino groups, where a ratio of primary to secondary to tertiary amino groups ranges from 1:0.8:0.5 to 1:1.3:0.8.

5. The plastic composite component according to claim 1, wherein the polyethyleneimine is a hyperbranched polymer having a degree of branching DB of from 10% to 99%, where DB is defined as DB (%) =100 x(T+Z)/(T+Z+L) where T is a mean number of terminal-bonded monomer units, Z is a mean number of monomer units that form branches and L is a mean number of linear-bonded monomer units in the polyethyleneimine.

6. The plastic composite component according to claim 1, wherein the plastic composite component comprises 0.01% to 5% by weight of polyethyleneimine, based on a total weight of the plastic composite component.

7. The plastic composite component according to claim 2, wherein the second plastic component comprises the polyethyleneimine.

8. The plastic composite component according to claim 1, wherein the first fiber material is a continuous fiber material.

9. The plastic composite component according to claim 2, wherein the second plastic component comprises a second fiber material, which is a short fiber material.

10. The plastic composite component according to claim 2, wherein at least one of the surface composition and the second plastic component comprises iron powder.

11. A process for producing the plastic composite component according to claim 2, the process comprising: a) providing the first plastic component, and b) molding the second plastic component onto the surface of the first plastic component, wherein optionally the second plastic component comprises the polyethyleneimine.

12. The process according to claim 11, wherein, in a), the first plastic component is placed into a mold and, in b), the second plastic component is injected into the mold in a molten state.

13. A process for improving thermal aging resistance of a plastic composite component, the process comprising: a) providing a first plastic component comprising ia) a matrix composition comprising a polyamide matrix polymer and a first fiber material for reinforcement, and ib) a surface composition which comprises a polyamide surface polymer and a polyethyleneimide for improving the thermal aging resistance of the plastic composite component and forms a surface of the first plastic component, and b) molding a second plastic component comprising a polyamide molding polymer onto the surface of the first plastic component, wherein the matrix composition does not comprise any polyethyleneimine.

Description

EXAMPLES

(1) 1. Production of the First Plastic Component (C1)

(2) The first plastic component (C1) is produced using polyamides (PA6) having relative viscosities (RV) of 2.1 to 2.7 or polyamide (PA66) having a relative viscosity (RV) of 2.7, By means of an extruder, Lupasol WF from BASF SE or iron powder (CIP) is incorporated into these polyamides by compounding. Lupasol WF is a polyethyleneimine having CAS no.: 9002-98-6 with a molar mass of about 25 000 g/mol. The amounts of Lupasol WF used are reported in the tables which follow. The relative viscosity was measured to ISO 307. The iron powder (CIP) was added as a batch.

(3) The amounts of Lupasol WF and the amounts of iron powder (CIP) are reported in percent by weight, based on the total weight of the polyamide used in the matrix composition (MC) or in the surface composition (SC), in each case without fiber material.

(4) After production of the polyamide matrix polymer (PAM) comprising the stated amounts of Lupasol WF and amounts of iron powder (CIP) if appropriate, the resultant polyamide matrix polymer (PAM) was comminuted to a fine powder by grinding. This powder was subsequently applied to a woven continuous fiber mat (first fiber material (F1)) and melted. After production of the polyamide surface polymer (PAS) comprising the stated amounts of Lupasol WF and any amounts of iron powder (CIP), the resultant polyamide surface polymer (PAS) was comminuted to a fine powder by grinding. A further woven continuous fiber mat (first fiber material (F1)) was applied to the woven continuous fiber mat onto which the polyamide matrix polymer (PAM) had been melted. The powder of the polyamide surface polymer (PAS) was subsequently applied to the further woven continuous fiber mat and melted. Subsequently, the woven continuous fiber mats were treated under pressure and at a temperature above the melting temperature of the polyamide matrix polymer (PAM) and the polyamide surface polymer (PAS), in order to produce the first plastic component (C1).

(5) The composition of the matrix composition (MC) and the surface composition (SC) of the first plastic part is reported in tables 1, 2 and 4 below.

(6) A second plastic component (C2) was subsequently molded onto the first plastic component (C1) thus obtained. For this purpose, a polyamide (PA6) was used as polyamide molding polymer (PAA).

(7) Lupasol WF was added to the second plastic component (C2) by means of an extruder. The amounts of Lupasol WF used and any amounts of iron powder (CIP) used are reported in tables 3 and 5. The weight data shown therein denote the percentages by weight, based on the total weight of the polyamide molding polymer (PAA) used.

(8) For molding of the second plastic component (C2) onto the first plastic component (C1), the first plastic component (C1) was inserted into a mold and heated. The second plastic component (C2) was subsequently melted and injected into the mold.

(9) The plastic component (C1) used was a specimen which had a surface area of 45 cm. A polymer component (C2) of length 4 cm and width 0.4 cm was molded onto this surface. The bonding surface area between C1 and C2 was thus 40.4 cm.

(10) The compositions of the second plastic component (C2) are reported in tables 3 and 5.

(11) To determine the thermal aging resistance (TAR) of the plastic composite components (CC/C1), the flexural strength of the plastic composite components (CC/C1) was measured before and after storage. Flexural strength was measured to DIN EN ISO 14125:2011.

(12) The temperature and duration of thermal storage is reported in the tables. The thermal storage was conducted in an air circulation oven.

(13) In the plastic composite components (CC/C1+C2), the adhesion between the plastic components was determined by measuring the tensile strength (MPa). The tensile strength was measured by a tensile test wherein the force needed to separate the plastic components (C1) and (C2) of the plastic composite component (CC/C1+C2) from one another was measured. For this purpose, the force was increased at a rate of 5 mm per minute.

(14) The examples demonstrate that the adhesion between the first plastic component (C1) and the second plastic component (C2) is distinctly improved after thermal storage by the use of a poiyethyleneimine (PEI) when the surface composition (SC) of the first plastic component (C1) and/or the second plastic component (C2) comprises a polyethyleneimine (PEI).

(15) TABLE-US-00001 TABLE 1 CC/C1 examples: 1 2 3 4 5 6 SC: PA6 (relative viscosity) 2.2 2.2 2.7 2.7 2.2 2.7 Lupasol WF 0.5 0.5 0.5 0.5 MC: PA6 (relative viscosity) 2.2 2.2 2.7 2.7 2.2 2.7 Lupasol WF 0.5 0.5 Thermal aging temperature: 180 C. 180 C. 180 C. 180 C. 180 C. 180 C. Decrease in flexural 20% 1% 22% none 1% none strength after 1000 h: Decrease in flexural 27% 12% 25% 11% 11% 12% strength after 2000 h:

(16) TABLE-US-00002 TABLE 2 CC/C1 examples: 7 8 9 10 11 17 SC: PA6 (relative viscosity) 2.7 2.2 2.2 2.7 2.7 2.7 Lupasol WF 0.5 0.5 0.5 0.5 0.5 Iron powder (CIP) 1 1 1 1 MC: PA6 (relative viscosity) 2.7 2.2 2.2 2.7 2.7 2.7 Lupasol WF 0.5 0.5 0.5 Iron powder (CIP) 1 1 1 Thermal aging temperature: 200 C. 200 C. 200 C. 200 C. 200 C. 200 C. Decrease in flexural 26% 9% none 2% none 2% strength after 1000 h: Decrease in flexural 70% 43% 22% 23% 23% 24% strength after 2000 h:

(17) TABLE-US-00003 TABLE 3 CC/C1 + C2 examples: 1a) 2a) 8a) 9a) 11a) 11b) 17a) C1 1 2 8 9 11 11 17 C2 PA6 (relative viscosity) 2.7 2.7 2.7 2.7 2.7 2.7 2.7 Lupasol WF 0.5 0.5 0.5 0.5 0.5 0.5 iron powder (CIP) 1 1 1 Analysis: Thermal aging 200 C. 200 C. 200 C. 200 C. 200 C. 200 C. 200 C. temperature (1000 h): Tensile strength (MPa): 11 11 16 19 20 18 18

(18) TABLE-US-00004 TABLE 4 CC/C1 examples 12 13 14 15 16 18 SC: PA66 (relative viscosity) 2.7 2.7 2.7 2.7 2.7 2.7 Lupasol WF 0.5 0.5 0.5 0.5 0.5 Iron powder (CIP) 1 1 1 1 MC: PA66 (relative viscosity) 2.7 2.7 2.7 2.7 2.7 2.7 Lupasol WF 0.5 0.5 0.5 Iron powder (CIP) 1 1 1 Thermal aging temperature: 220 C. 220 C. 220 C. 220 C. 220 C. 220 C. Decrease in flexural strength 44% 35% none none none none after 1000 h: Decrease in flexural strength no 70% 3% 5% 3% 4% after 2000 h: longer any

(19) TABLE-US-00005 TABLE 5 CC/C1 + C2 examples: 12a) 13a) 13b) 12b) 16a) 16b) 18a) C1 12 13 13 12 16 16 18 C2 PA6 (relative viscosity) 2.7 2.7 2.7 2.7 2.7 2.7 2.7 Lupasol WF 0.5 0.5 0.5 0.5 0.5 0.5 Iron powder (CIP) 1 1 1 1 Thermal aging 220 C. 220 C. 220 C. 220 C. 220 C. 220 C. 220 temperature (1000 h): Tensile strength (MPa): 5 7 5 4 16 11 16