Composite plastic part with improved adhesion between the plastic components contained in the composite plastic part

Abstract

The present invention relates to a plastic composite component (CC) which has a first plastic component (C1) and a second plastic component (C2) and comprises a polyethyleneimine (PEI) for improving the adhesion between C1 and C2. The present invention further relates to a process for producing this plastic composite component (CC), to a process for improving the adhesion between a first plastic component (C1) and a second plastic component (C2) in a plastic composite component (CC) and to the use of polyethyleneimine for improving the adhesion between a first plastic component (C1) and a second plastic component (C2) in a plastic composite component (CC).

Claims

1. A process for producing a plastic composite component (CC) comprising the following steps: a) providing a first plastic component (C1) comprising ia) a matrix composition (MC) comprising a polyamide matrix polymer (PAM) and at least one first fiber material (F1) for reinforcement, and ib) a surface composition (SC) which comprises a polyamide surface polymer (PAS) and forms a surface of C1, and b) molding a second plastic component (C2) comprising a polyamide molding polymer (PAA) onto the surface of C1; wherein SC and/or C2 comprises a polyethyleneimine (PEI) for improving the adhesion between C1 and C2, wherein in step a), C1 is placed into a mold and in step b), C2 is injected into the mold in the molten state.

2. The process for producing a plastic composite component (CC) according to claim 1, wherein the polyethyleneimine (PET) has a weight-average molecular weight M.sub.W in the range from 600 to 300 000 g/mol.

3. The process for producing a plastic composite component (CC) according to claim 1, wherein the polyethyleneimine (PEI) comprises primary, secondary and tertiary amino groups, where the ratio of primary to secondary to tertiary amino groups is in the range from 1:0.8:0.5 to 1:1.3:0.8.

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

5. The process for producing a plastic composite component (CC) according to claim 1, wherein the plastic composite component (CC) comprises 0.01% to 5% by weight of polyethyleneimine (PEI), based on the total weight of the plastic composite component (CC).

6. The process for producing a plastic composite component (CC) according to claim 1, wherein SC and C2 comprise polyethyleneimine (PEI).

7. The process for producing a plastic composite component (CC) according to claim 1, wherein the first fiber material (F1) is a continuous fiber material.

8. The process for producing a plastic composite component (CC) according to claim 1, wherein the surface composition (SC), the matrix composition (MC) and the second plastic component (C2) comprise polyethyleneimine (PET).

9. The process for producing a plastic composite component (CC) according to claim 1, wherein C2 comprises a second fiber material (F2).

10. The process for producing a plastic composite component (CC) according to claim 1, wherein the second fiber material (F2) is a short fiber material.

11. A plastic composite component (CC) comprising i) a first plastic component (C1) comprising ia) a matrix composition (MC) comprising a polyamide matrix polymer (PAM) and at least one first fiber material (F1) for reinforcement, and ib) a surface composition (SC) which comprises a polyamide surface polymer (PAS) and forms a surface of C1, and ii) a second plastic component (C2) which comprises a polyamide molding polymer (PAA) and has been molded onto the surface of C1, wherein SC and/or C2 comprises a polyethyleneimine (PEI) for improving the adhesion between C1 and C2.

12. A method for improving the adhesion between a first plastic component (C1) and a second plastic component (C2) in a plastic composite component (CC), wherein CC comprises i) a first plastic component (C1) comprising ia) a matrix composition (MC) comprising a polyamide matrix polymer (PAM) and at least one first fiber material (F1) for reinforcement, and ib) a surface composition (SC) which comprises a polyamide surface polymer (PAS) and forms a surface of C1, and ii) a second plastic component (C2) which comprises a polyamide molding polymer (PAA) and has been molded onto the surface of C1; the method comprising incorporating a polyethyleneimine (PEI) into SC and/or C2.

13. A process for improving the adhesion between a first plastic component (C1) and a second plastic component (C2) in a plastic composite component (CC), comprising the following steps: a) providing a first plastic component (C1) comprising ia) a matrix composition (MC) comprising a polyamide matrix polymer (PAM) and at least one first fiber material (F1) for reinforcement, and ib) a surface composition (SC) which comprises a polyamide surface polymer (PAS) and forms a surface of C1, and b) molding a second plastic component (C2) comprising a polyamide molding polymer (PAA) onto the surface of C1, wherein SC and/or C2 comprises a polyethyleneimine (PEI) for improving the adhesion between C1 and C2, wherein in step a), C1 is placed into a mold and in step b), C2 is injected into the mold in the molten state.

14. A plastic composite component (CC) which is obtained by the process according to claim 1.

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 2.9. By means of an extruder, Lupasol WF from BASF SE is incorporated into these polyamides by compounding. Lupasol WE 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.

(3) The amounts of Lupasol WF 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, 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, 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 table 1 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 (FAA). The polyamides used had relative viscosities (RV) of 2.1 to 2.9.

(7) Lupasol WF was added to the second plastic component (C2) by means of an extruder. The amounts of Lupasol WF used are reported in table 2. 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 composition of the second plastic component (C2) is reported in table 2.

(11) Example 1a) and example 3a) are comparative examples since, in this plastic composite component (CC), neither the surface composition (SC) nor the second plastic component (C2) comprises a polyethyleneimine (Lupasol WF). In the inventive example 1b), the surface composition (SC) does not comprise any Lupasol WF. On the other hand, the second plastic component (C2) comprises Lupasol WF.

(12) In example 5a), not only SC but also C2 comprises Lupasol WF.

(13) In example 2a), not only SC and MC but also C2 comprises Lupasol WF.

(14) In example 4a), not only SC and MC but also C2 comprises Lupasol WF.

(15) In example 6a), likewise, SC and also C2 comprises Lupasol WF.

(16) In the plastic composite components (CC) produced, 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) from one another was measured. For this purpose, the force was increased at a rate of 5 mm per minute.

(17) The examples demonstrate that the adhesion between the first plastic component (C1) and the second plastic component (C2) is distinctly improved by the use of a polyethyleneimine (PEI) when the surface composition (SC) of the first plastic component (C1) and/or the second plastic component (C2) comprises a polyethyleneimine (PEI). To enhance the adhesion, it is sufficient when one of the two plastic components (C1/C2) comprises a polyethyleneimine (PEI). Even better adhesion values are achieved when both SC and C2 comprise a polyethyleneimine (PEI).

(18) TABLE-US-00003 TABLE 1 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 0.5 0 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 Lupasol G20

(19) TABLE-US-00004 TABLE 2 CC examples 1a) 1b) 5a) 2a) 3a) 4a) 6a) C1 1 1 5 2 3 4 6 C2 PA6 (relative 2.2 2.2 2.2 2.2 2.7 2.7 2.7 viscosity) Lupasol WF 0 0.5 0.5 0.5 0 0.5 0.5 Tensile strength (MPa) 16 19 19 19 18 20 21