HIGH WELD LINE STRENGTH POLYPROPYLENE/POLYCARBONATE ALLOY AND PREPARATION METHOD THEREOF

Abstract

The present invention discloses a high weld line strength polypropylene/polycarbonate alloy, including the following components in parts by weight: 5 parts to 40 parts of a polypropylene; 40 parts to 85 parts of a polycarbonate; and 1 part to 15 parts of an ethylene copolymer compatibilizer. The high weld line strength polypropylene/polycarbonate alloy has high weld line strength, a good melt index and an excellent chemical resistance.

Claims

1. A high weld line strength polypropylene/polycarbonate alloy, comprising the following components in parts by weight: 5 parts to 40 parts of a polypropylene, 40 parts to 85 parts of a polycarbonate, and 1 part to 15 parts of an ethylene copolymer compatibilizer.

2. The high weld line strength polypropylene/polycarbonate alloy according to claim 1, wherein the polypropylene is selected from at least one of a copolymerized polypropylene and a homopolymerized polypropylene.

3. The high weld line strength polypropylene/polycarbonate alloy according to claim 1, wherein the ethylene copolymer compatibilizer is selected from at least one of an ethylene copolymer of acrylic acid, an ethylene-vinyl acetate copolymer, a styrene-butadiene-styrene copolymer, a styrene-ethylene-butadiene-styrene copolymer, and a styrene-ethylene-propylene-styrene copolymer; the ethylene copolymer of acrylic acid is selected from at least one of an ethylene-methacrylic acid copolymer, an ethylene-ethyl acrylate copolymer, and an ethylene-butyl acrylate copolymer.

4. The high weld line strength polypropylene/polycarbonate alloy according to claim 3, wherein the ethylene copolymer compatibilizer is selected from the ethylene copolymer of acrylic acid.

5. The high weld line strength polypropylene/polycarbonate alloy according to claim 1, wherein the ethylene copolymer compatibilizer is selected from an ethylene copolymer compatibilizer containing a reactive active group, wherein an ethylene copolymer is selected from at least one of an ethylene copolymer of acrylic acid, an ethylene-vinyl acetate copolymer, a styrene-butadiene-styrene copolymer, a styrene-ethylene-butadiene-styrene copolymer, and a styrene-ethylene-propylene-styrene copolymer, the reactive active group is at least one of a maleic anhydride group and an epoxy group, and a grafting ratio of the reactive active group is 0.1% to 15%; and the ethylene copolymer of acrylic acid is selected from at least one of an ethylene-methacrylic acid copolymer, an ethylene-ethyl acrylate copolymer, and an ethylene-butyl acrylate copolymer.

6. The high weld line strength polypropylene/polycarbonate alloy according to claim 5, wherein the ethylene copolymer is selected from the ethylene copolymer of acrylic acid.

7. The high weld line strength polypropylene/polycarbonate alloy according to claim 1, wherein the polycarbonate is selected from an aromatic polycarbonate, an aliphatic polycarbonate, and an aromatic-aliphatic polycarbonate; the polycarbonate has a weight average molecular weight of 18,000 to 28,000; and in parts by weight, 0 part to 10 parts of a processing aid and/or an additive are further comprised.

8. The high weld line strength polypropylene/polycarbonate alloy according to claim 1, wherein the high weld line strength polypropylene/polycarbonate alloy has weld line strength of 60% or more, and a weld line strength test is according to ASTM D638 standard test.

9. A preparation method of the high weld line strength polypropylene/polycarbonate alloy of claim 7, comprising the following steps: mixing the polycarbonate, polyolefin, the ethylene copolymer compatibilizer, and a processing aid and/or an additive evenly according to a ratio in a high-speed mixer; then adding into a twin-screw extruder, melt mixing at a temperature of 220° C. to 240° C., and then granulating, cooling and drying to obtain the high weld line strength polypropylene/polycarbonate alloy.

10. The preparation method of the high weld line strength polypropylene/polycarbonate alloy according to claim 9, wherein the polypropylene has a melt index of 40 g/10 min to 150 g/10 min under a test condition of 230° C., 2.16 kg; and the ethylene copolymer compatibilizer has a melt index of 0.2 g/10 min to 50 g/10 min under a test condition of 190° C., 2.16 kg.

11. The high weld line strength polypropylene/polycarbonate alloy according to claim 2, wherein the high weld line strength polypropylene/polycarbonate alloy has weld line strength of 60% or more, and a weld line strength test is according to ASTM D638 standard test.

12. The high weld line strength polypropylene/polycarbonate alloy according to claim 3, wherein the high weld line strength polypropylene/polycarbonate alloy has weld line strength of 60% or more, and a weld line strength test is according to ASTM D638 standard test.

13. The high weld line strength polypropylene/polycarbonate alloy according to claim 4, wherein the high weld line strength polypropylene/polycarbonate alloy has weld line strength of 60% or more, and a weld line strength test is according to ASTM D638 standard test.

14. The high weld line strength polypropylene/polycarbonate alloy according to claim 5, wherein the high weld line strength polypropylene/polycarbonate alloy has weld line strength of 60% or more, and a weld line strength test is according to ASTM D638 standard test.

15. The high weld line strength polypropylene/polycarbonate alloy according to claim 6, wherein the high weld line strength polypropylene/polycarbonate alloy has weld line strength of 60% or more, and a weld line strength test is according to ASTM D638 standard test.

16. The high weld line strength polypropylene/polycarbonate alloy according to claim 7, wherein the high weld line strength polypropylene/polycarbonate alloy has weld line strength of 60% or more, and a weld line strength test is according to ASTM D638 standard test.

17. The high weld line strength polypropylene/polycarbonate alloy according to claim 8, wherein the high weld line strength polypropylene/polycarbonate alloy has the weld line strength of 65% or more, and the weld line strength test is according to ASTM D638 standard test.

18. The preparation method of the high weld line strength polypropylene/polycarbonate alloy according to claim 10, wherein the polypropylene has the melt index of 60 g/10 min to 150 g/10 min under the test condition of 230° C., 2.16 kg.

19. The preparation method of the high weld line strength polypropylene/polycarbonate alloy according to claim 10, wherein the ethylene copolymer compatibilizer has the melt index of 0.4 g/10 min to 35 g/10 min under the test condition of 190° C., 2.16 kg.

Description

DESCRIPTION OF THE EMBODIMENTS

[0026] The present invention will be further illustrated below by specific implementations, the following embodiments are preferred implementations of the invention, but the implementations of the present invention are not limited by the following embodiments.

[0027] Raw materials of Embodiments and Comparative Examples are commercially available, specifically:

[0028] polypropylene: copolymerized polypropylene;

[0029] EMA: ethylene-methacrylic acid copolymer;

[0030] EEA: ethylene-ethyl acrylate copolymer;

[0031] EMA-g-GMA: ethylene-methacrylic acid graft epoxy group (GMA is an epoxy group);

[0032] EVA: ethylene-vinyl acetate copolymer;

[0033] SEBS: styrene-ethylene-butadiene-styrene copolymer;

[0034] compatibilizer B: PP-G-MAH (polypropylene graft maleic anhydride);

[0035] polycarbonate A: an aromatic polycarbonate with a weight average molecular weight being 28,000;

[0036] polycarbonate B: an aliphatic polycarbonate with a weight average molecular weight being 18,000;

[0037] polycarbonate C: an aromatic polycarbonate with a weight average molecular weight being 8,000;

[0038] polycarbonate D: an aromatic polycarbonate with a weight average molecular weight being 30,000;

[0039] anti-aging agent: anti-oxidant:anti-ultraviolet aging agent=1:1.

[0040] A preparation method of a polycarbonate alloy in Embodiments and Comparative Examples: A preparation method of a polypropylene/polycarbonate alloy in Embodiments and Comparative Examples: a polycarbonate, a polypropylene, a compatibilizer, and a processing aid and/or an additive were mixed evenly according to a ratio in a high-speed mixer; then added into a twin-screw extruder, melt mixed at a temperature of 220° C. to 240° C., and then granulated, cooled and dried to obtain a high weld line strength polycarbonate alloy.

[0041] Each Test Method:

[0042] (1) Alloy Melt Index (MFR): according to a test ASTM D1238, a test condition of the polycarbonate alloy is 260° C., 2.16 kg;

[0043] (2) Chemical resistance: a sample is immersed in various chemicals (methanol, 10% sulfuric acid, thinning solvent, acetone, soybean oil, and ink) for 7 days and visually observed to evaluate the chemical resistance. There are four grades: completely no changes in appearance marked as excellent, a slight swelling marked as good, a micro number of cracks marked as medium, and a large number of cracks or fractures marked as poor.

[0044] (3) Weld line strength: characterized by a weld line coefficient Flu:

F.sub.KL=TS.sub.X/TS.sub.0×100%

[0045] TS.sub.X is tensile strength of weld line and TS.sub.0 is tensile strength without the weld line, and an ASTM D638 standard test is applied.

TABLE-US-00001 TABLE 1 Ingredients and ratios (in parts by weight) and each performance test results of Embodiments 1 to 10 Embodi- Embodi- Embodi- Embodi- Embodi- ment ment ment ment ment 1 2 3 4 5 Polypropylene MFR, 40 40 40 40 40 g/10 min Amount, 15 15 15 15 15 parts Polycarbonate A, parts 80 80 80 80 80 Compatibilizer Species of — — — — — A reactive active group Grafting — — — — — rate of reactive active group, % Ethylene EMA EMA EMA EMA EMA copolymer MFR, 0.2 0.4 5 10 15 g/10 min Amount, 5 5 5 5 5 parts Anti-aging agent 0.5 0.5 0.5 0.5 0.5 MFR, g/10 min 12 13 16 23 27 Weld line strength, % 65 70 75 80 85 Chemical resistance excellent excellent excellent excellent excellent Embodi- Embodi- Embodi- Embodi- Embodi- ment ment ment ment ment 6 7 8 9 10 Polypropylene MFR, 40 40 60 80 100 g/10 min Amount, 15 15 15 15 15 parts Polycarbonate A, parts 80 80 80 80 80 Compatibilizer Species of — — — — — A reactive active group Grafting — — — — — rate of reactive active group, % Ethylene EMA EMA EMA EMA EMA copolymer MFR, 35 50 5 5 5 g/10 min Amount, 5 5 5 5 5 parts Anti-aging agent 0.5 0.5 0.5 0.5 0.5 MFR, g/10 min 30 36 18 22 25 Weld line strength, % 81 68 80 83 85 Chemical resistance excellent excellent excellent excellent excellent

TABLE-US-00002 TABLE 2 Ingredients and ratios (in parts by weight) and each performance test results of Embodiments 11 to 20 Embodi- Embodi- Embodi- Embodi- Embodi- ment ment ment ment ment 11 12 13 14 15 Polypropylene MFR, 150 40 40 40 100 g/10 min Amount, 15 15 15 15 15 parts Polycarbonate A, parts 80 80 80 80 80 Polycarbonate B, parts — — — — — Polycarbonate C, parts — — — — — Polycarbonate D, parts — — — — — Compatibilizer Species of — — — — GMA A reactive active group Grafting — — — — 0.1 rate of reactive active group, % Ethylene EMA EEA EVA SEBS EMA copolymer MFR, 5 0.2 0.2 0.2 5 g/10 min Amount, 5 5 5 5 5 parts Anti-aging agent 0.5 0.5 0.5 0.5 0.5 MFR, g/10 min 38 13 11 12 22 Weld line strength, % 89 66 61 60 87 Chemical resistance excellent excellent excellent excellent excellent Embodi- Embodi- Embodi- Embodi- Embodi- ment ment ment ment ment 16 17 18 19 20 Polypropylene MFR, 100 100 100 100 100 g/10 min Amount, 15 15 15 15 15 parts Polycarbonate A, parts 80 80 — — — Polycarbonate B, parts — — 80 — — Polycarbonate C, parts — — — 80 — Polycarbonate D, parts — — — — 80 Compatibilizer Species of GMA GMA — — — A reactive active group Grafting 5 15 — — — rate of reactive active group, % Ethylene EMA EMA EMA EMA EMA copolymer MFR, 5 5 5 5 5 g/10 min Amount, 5 5 5 5 5 parts Anti-aging agent 0.5 0.5 0.5 0.5 0.5 MFR, g/10 min 18 14 31 34 21 Weld line strength, % 89 91 85 74 65 Chemical resistance excellent excellent excellent excellent excellent

TABLE-US-00003 TABLE 3 Ingredients and ratios (in parts by weight) and each performance test results of Embodiments 21 to 22 and Comparative Examples Embodi- Embodi- Comparative Comparative Comparative Comparative ment ment Example Example Example Example 21 22 1 2 3 4 Polypropylene MFR, 100 100 100 100 30 40 g/10 min Amount, 15 15 15 15 15 15 parts Polycarbonate A, 80 80 80 80 80 80 parts Compatibilizer Species — — — — — — A of reactive active group Grafting — — — — — — rate of reactive active group, % Ethylene EMA EMA — — EMA EMA copolymer MFR, 5 5 — — 5 60 g/10 min Amount, 1 15 — — 5 5 parts Amount of — — — 5 — — compatibilizer B, parts Anti-aging agent 0.5 0.5 0.5 0.5 0.5 0.5 MFR, g/10 min 12 28 20 30 11 40 Weld line 77 89 10 25 53 57 strength, % Chemical resistance excellent excellent poor good good good

[0046] It can be seen from Embodiments 1 to 7 and Comparative Example 4 that as an increase of the melt index of the ethylene copolymer compatibilizer, the melt index of the product increases and the weld line strength is in an inverted U-shape; when the melt index of the ethylene copolymer compatibilizer is 0.4 g/10 min to 35 g/10 min (under a test condition of 190° C., 2.16 kg), the weld line strength of the product is relatively high; when the melt index of the ethylene copolymer compatibilizer is 60 g/10 min (under the test condition of 190° C., 2.16 kg), the weld line strength and the chemical resistance of the product are greatly reduced.

[0047] It can be seen from Embodiments 3, 8 to 11 that as an increase of the melt index of the polyolefin, the weld line strength and the melt index of the product are increased.

[0048] It can be seen from Embodiment 10 and Embodiments 15 to 17 that the ethylene copolymer compatibilizer containing reactive active groups is more capable of increasing the weld line strength compared with the ethylene copolymer compatibilizer containing no reactive active groups.

[0049] It can be seen from Embodiments 1, 12, 13, 14 that when the ethylene copolymer of acrylic acid is as a compatibilizer, each performance of the product is relatively good.

[0050] It can be seen from Embodiment 3 and Comparative Example 3 that when the melt index of the polyolefin is 30 g/10 min (under the test condition of 230° C., 2.16 kg), the weld line strength of the product is considerably decreased and the melt index is relatively low.

[0051] It can be seen from Embodiments 10, 18 to 20 that the product prepared by a polycarbonate with a weight average molecular weight being 18,000 to 28,000 has relatively high weld line strength.