Thermoplastic elastomer composition

Abstract

The invention relates to a thermoplastic elastomer composition comprising a mixture of a. 5-50 wt. % of a block copolymer type thermoplastic polyurethane elastomer (TPE-U) b. 5-50 of a block copolymer type thermoplastic co-polyester elastomer (TPE-C), and c. 10-60 wt. % of a thermoplastic styrenic block copolymer (TPE-S), wherein the wt. % is based on the total content of the elastomer composition. The elastomer composition might be efficiently connected with polar polymers so that corresponding polymer articles are formed.

Claims

1. A thermoplastic elastomer composition comprising a mixture of 5-50 wt. % of a block copolymer type thermoplastic polyurethane elastomer (TPE-U), 5-50 wt. % of a block copolymer type thermoplastic co-polyester elastomer (TPE-C), wherein at least 70 wt. % of the TPE-C is represented by TPE-C comprising a block copolymer of alternating hard and soft blocks, wherein the soft blocks contain ester and ether linkages and structural units of aromatic dicarboxylic acids, and 10-60 wt. % of a thermoplastic styrenic block copolymer (TPE-S), wherein wt. % is based on the total content of the elastomer composition.

2. The thermoplastic elastomer composition of claim 1, wherein the sum of the contents of the TPE-U, the TPE-C, and the TPE-S is 40-100 wt. %.

3. The thermoplastic elastomer composition of claim 1, wherein the sum of the contents of the TPE-U and the TPE-C is 30-60 wt. %.

4. The thermoplastic elastomer composition of claim 1, wherein the proportion of the contents of the TPE-U and the TPE-C is 1:5-5:1.

5. The thermoplastic elastomer composition of claim 1, wherein the content of the TPE-S is 22-50 wt. %.

6. The thermoplastic elastomer composition of claim 1, wherein the mixture also comprises one or more further ingredients.

7. The thermoplastic elastomer composition of claim 1, the thermoplastic elastomer composition having a shore hardness in the range from A20 up to D50.

8. The thermoplastic elastomer composition of claim 1, wherein at least 70 wt. % of the TPE-U is represented by TPE-U having a linear structure.

9. The thermoplastic elastomer composition of claim 1, wherein at least 90 wt. % of the TPE-S is represented by a A-B-A triblock copolymer wherein the A block contains structural units derived from styrene and the B block contains structural units derived from one or more of butadiene, isoprene, and isobutene.

10. An article comprising two different polymeric materials directly connected with each other, one of the two different polymeric materials including a thermoplastic elastomer composition comprising a mixture of: 5-50 wt. % of a block copolymer type thermoplastic polyurethane elastomer (TPE-U), 5-50 wt. % of a block copolymer type thermoplastic co-polyester elastomer (TPE-C), wherein at least 70 wt. % of the TPE-C is represented by TPE-C comprising a block copolymer of alternating hard and soft blocks, wherein the soft blocks contain ester and ether linkages and structural units of aromatic dicarboxylic acids, and 10-60 wt. % of a thermoplastic styrenic block copolymer (TPE-S), wherein wt. % is based on the total content of the elastomer composition.

11. The article of claim 10, wherein the other polymeric material of the two different polymeric materials comprises a polar polymer component.

12. A method of preparing an article that comprises two different polymeric materials, the method comprising: directly connecting surfaces of the two different polymeric materials without pre-treatment, wherein one of the two different polymeric materials is a thermoplastic elastomer composition comprising a mixture of: 5-50 wt. % of a block copolymer type thermoplastic polyurethane elastomer (TPE-U), 5-50 wt. % of a block copolymer type thermoplastic co-polyester elastomer (TPE-C), wherein at least 70 wt. % of the TPE-C is represented by TPE-C comprising a block copolymer of alternating hard and soft blocks, wherein the soft blocks contain ester and ether linkages and structural units of aromatic dicarboxylic acids, and 10-60 wt. % of a thermoplastic styrenic block copolymer (TPE-S), wherein wt. % is based on the total content of the elastomer composition.

13. The thermoplastic elastomer composition of claim 6, wherein the one or more further ingredients includes one or more of a compatibilizer, a polyolefin, a plasticizer, and a filler.

14. The article of claim 11, wherein the polar polymer component comprises one or more of a polycarbonate (PC), a polyethylene terephthalate (PET), an acrylonitrile-butadiene-styrene polymer (ABS), and a polyamide (PA).

15. The method of claim 12, wherein the article is prepared by injection molding.

16. The thermoplastic elastomer composition of claim 1, comprising, as the TPE-S, 10-60 wt. % of one or more of SEBS and SEEPS.

17. The thermoplastic elastomer composition of claim 1, wherein the elastomer composition comprises no oil or oil in an amount below 15 wt. % based on the total content of the elastomer composition.

18. The thermoplastic elastomer composition of claim 1, wherein the elastomer composition comprises, as the TPE-S, 10-60 wt. % of SEEPS, and the elastomer composition comprises no oil or oil in an amount below 15 wt. % based on the total content of the elastomer composition.

Description

(1) Below the present invention is described in more detail by using examples.

(2) The tests of numbers 1-21 are according to the present invention and the experiments due to Ref. 1-Ref. 9 are comparison tests which are not according to the present invention.

(3) TABLE-US-00001 test Raw materials Ref. 1 Ref. 2 Ref. 3 Ref. 4 1 2 TPE-U.sup.1) 40 45 20 33 TPE-C.sup.2) 45 40 20 12 PP.sup.6) 9.7 9.7 9.7 9.7 9.7 9.7 TPE-S.sup.11) 16 16 16 16 19 16 Oil.sup.7) 24 24 24 24 24 24 Compatibilizer.sup.8) 5 2.5 2.5 5 2.5 3.2 Compatibilizer.sup.9) 5 2.5 2.5 5 2.5 3.2 Shore hardness A 70 77 67 80 65 76 Adhesive force 9 23 13 10 62 30 [N] ABS Adhesive force 5 26 11 21 40 23 [N] PC

(4) TABLE-US-00002 test Raw materials Ref. 6 Ref. 5 3 4 TPE-U.sup.4) 50 25 37.5 TPE-C.sup.10) 50 25 12.5 PP.sup.6) 10.5 10.5 10.5 10.5 TPE-S.sup.3) 39.2 39.2 39.2 39.2 Shore hardness A 78 86 84 79 Adhesive force [N] ABS 37 34 41 49 Adhesive force [N] PC 11 36 38 70

(5) It is shown that the combination of TPE-C and TPE-U in the presence of TPE-S provides a synergistic effect concerning the improvement of the adhesion. For example the comparison of Ref. 3 with test 2 shows that the addition of TPE-C component provides a significant improvement of the adhesion.

(6) TABLE-US-00003 test Raw materials 5 6 7 8 TPE-U.sup.4) 30 15 29 44.5 TPE-C.sup.10) 10 45 20 8 PP.sup.6) 10.5 10.5 10.5 10.5 TPE-S.sup.3) 49.2 29.2 40.2 36.7 Shore hardness A 79 82 82 76 Adhesive force [N] ABS 29 40 35 35 Adhesive force [N] PC 34 60 50 70

(7) Tests 5-8 show that the compositions according to the present invention generally provide good or even very good adhesion results.

(8) TABLE-US-00004 test Raw materials 9 10 11 12 13 14 15 16 17 TPE-U.sup.4) 37.5 37.5 37.5 37.5 37.5 37.5 37.5 37.5 37.5 TPE-C.sup.10) 12.5 12.5 12.5 12.5 12.5 12.5 12.5 12.5 12.5 TPE-S.sup.3) 49.7 39.7 29.7 19.7 39.7 29.7 39.7 29.7 19.7 chalk.sup.12) — 10 20 30 — — — — — talc.sup.13) — — — — 10 20 — — — kaolin.sup.14) — — — — — — 10 20 30 Shore 70 72 75 78 73 78 75 77 81 hardness A Adhesive 120 100 120 120 130 115 120 140 120 force [N] ABS Adhesive 100 110 120 140 130 105 120 120 130 force [N] PC Adhesive 75 70 90 95 100 110 95 95 60 force [N] PET

(9) Tests 9-17 show that also the use of additional mineral ingredients allows a good adhesion. It is further shown that an appropriate shore hardness might be achieved without additional softeners even if relative high amounts of mineral fillers are used.

(10) TABLE-US-00005 test Raw materials 18 Ref. 7 TPE-U.sup.4) 37.5 37.5 TPE-C.sup.5) 12.5 12.5 TPE-S.sup.3) 10 5 chalk.sup.12) 29.2 34.2 PP.sup.6) 10.5 10.5 Shore hardness A 87-92 88-93 Compression set: 22 h-23° C. 55 57 Compression set: 22 h-70° C. 58 61 Compression set: 22 h-100° C. 92 94 Adhesive force PC [N] 38 28 Adhesive force ABS [N] 90 32

(11) It is shown that a sufficient amount of TPE-S on the one hand is important for the adhesion and on the other hand provides a positive influence concerning the relevant compression set results.

(12) TABLE-US-00006 test Raw material Ref. 8 Ref. 9 19 20 21 TPE-U.sup.4) 5.0 15.0 20.0 25.0 30.0 TPE-C.sup.10) 15.0 5.0 20.0 25.0 30.0 TPE-S.sup.3) 69.2 69.2 49.2 39.2 29.2 PP .sup.6) 10.5 10.5 10.5 10.5 10.5 Melt flow index/ 6.29 4.68 4.25 41.5 32.1 190°/10 kg (250° C.) at (230° C.) at 190° C. no 190° C. no flow flow Shore hardness A 70 71 82 83 92 Adhesive force [N] ABS 9 5 13 40 40 Adhesive force [N] PC 8 6 19 27 27 Compression set: 26 35 20 18 26 22 h-70° C. Compression set: 40 43 29 26 35 22 h-100° C.

(13) Ref 8 and 9 (in comparison with tests 19-21) show that the amount of TPE-S should not be too high. In these both comparative experiments melt temperatures of above 200° C. are necessary in order to process the mixture (to have a flow through the processing nozzle). However, such high melt temperatures typically deteriorate the quality of the final product. Furthermore, the adhesion values and the compression set results indicate that the TPE-S amount should not be too high.

(14) Used Raw Materials:

(15) .sup.1) Desmopan® 9370A: TPE-U, manufactured by Covestro Deutschland AG, melt temperature 195-215° C., produced by polyaddition of three basis raw materials: polyol (long chain diol), short chain diol (as chain extender) and diisocyanate; as polyols generally polyesters, polyethers or polycarbonatdiols are used
.sup.2) Riteflex® 435: TPE-C, a product of Celanese Corp., a thermoplastic polyester elastomer with a 35 nominal shore D hardness; a block copolymer which offer a combination of hard and soft segments—providing the desirable properties of thermoset elastomers along with the processing ease of thermoplastics.
.sup.3) Dynasol Calprene® H6174: TPE-S, a hydrogenated rubber (SEBS), a linear structure ethylene-butylene/styrene thermoplastic copolymer, a product of the Dynasol group
.sup.4) Epamould 660 A 26: TPE-U, a transparent, plasticized, polyester based thermoplastic polyurethane with good crystallization rate, produced by Epaflex Polyurethanes S.P.A.
.sup.5) Sipolprene® 25170: TPE-C, an ether ester thermoplastic elastomer, manufactured by Sipol S.P.A., with a nominal hardness of Shore D 27 and a rheological behaviour, which makes it suitable for injection moulding and extrusion processing
.sup.6) DuPure® T 50: a polypropylene homopolymer produced with a phthalate-free catalyst and having a high flowability, produced by Ducor Petrochemicals B.V.
.sup.7) RAJOL® WP 350: a white mineral oil/liquid paraffin which is certified to be safe for incidental contact with food stuff, produced by Raj Petro Specialities (Europe) B.V.
.sup.8) SCONA® TSKD 9103: a compatibilizer/adhesion promoter for TPE-S; a styrene ethylene butylene styrene block copolymer functionalized with maleic anhydride, produced by BYK-Chemie GmbH
.sup.9) SCONA® TPPP 8112: a compatibilizer/adhesion promotor for TPE-S; a polypropylene functionalized with maleic anhydride, produced by BYK-Chemie GmbH
.sup.10) Sipolprene® 35180: TPE-C, an ether ester thermoplastic elastomer, manufactured by Sipol S.P.A., with a nominal hardness of Shore D 35 and a rheological behaviour, which makes it suitable for injection moulding and extrusion processing .sup.11) SEPTON™ 4077: TPE-S, a styrene-ethylene-ethylene-propylene-styrene-block-copolymer (SEEPS) material, product of Kuraray Co. Ltd. .sup.12) Calcilit 7G: calcium carbonate made from bright white marble rock of high chemical purity, product of Alpha Calcit Füllstoff GmbH & Co. KG .sup.13) PlusTalc H15: a Mg silicate based crystalline product (particles), improves brightness and mechanical reinforcement, product of Mondo Minerals BV .sup.14) BURGESS ICEBERG™: “a general purpose” kaolin clay, offering a good balance of optical and mechanical properties, product of Burgess Pigment Co.
Substrates Used for the Adhesion Tests:
ABS: acrylonitrile-butadiene-styrene polymer (Terlux 2802 TR)
PC: polycarbonate (Calibre 201-22)
PET: polyethylene terephthalate (Sky green S2008)

(16) The adhesion between the two relevant components is arranged by a corresponding injection molding process without a pre-treatment of the two adhesion partners.

(17) The used components were predried in a commercially general way before processed in the injection molding process. The harder components were separately injection molded and afterwards preheated at 70° C. for 2 h and put into a cavity. Then the composition according to the present invention was applied by injection molding. The used injection molding apparatus was a “Engel Victory VC 330”.

(18) Testing of the adhesion is performed according to VDI guideline 2019 as 90°-peel test using a zwick tensile testing machine. The evaluation of the peeling curve is made due to DIN ISO 6133 (norm for testing the tear propagation resistance of elastomers).

(19) Rating of the Adhesion:

(20) <10 N: no adhesion

(21) 10-20 N: weak adhesion

(22) 20-60 N: good adhesion

(23) >60 N: very good adhesion

(24) further test norms:

(25) TABLE-US-00007 Shore hardness A ASTM D 2240, 5 s Compression set (25% compression): 23° C., 22 h; [%] ISO 815 70° C., 22 h; [%] ISO 815 100° C., 22 h; [%] ISO 815 Melt flow index; [g/10 min] ISO 1133