Sound damping thermoplastic elastomer articles

Abstract

A sound damping article is formed from a thermoplastic elastomer compound that includes styrenic block copolymer, high softening point tackifier, plasticizer, and secondary polymer. The styrenic block copolymer has a Copolymer Tan Delta Peak Temperature and the thermoplastic elastomer compound has a Compound Tan Delta Peak Temperature. The Compound Tan Delta Peak Temperature is greater than the Copolymer Tan Delta Peak Temperature. The sound damping article exhibits useful vibration damping properties while also exhibiting beneficial sound and/or noise damping properties at or above room temperature.

Claims

1. A sound damping article formed from a thermoplastic elastomer compound, the compound comprising: (a) styrenic block copolymer having a Copolymer Tan Delta Peak Temperature; (b) tackifier having a softening point of at least about 80 C. according to ASTM 6493; (c) plasticizer; and (d) secondary polymer; wherein the compound has a Compound Tan Delta Peak Temperature, and the Compound Tan Delta Peak Temperature is greater than the Copolymer Tan Delta Peak Temperature.

2. The sound damping article of claim 1, wherein the Copolymer Tan Delta Peak Temperature is greater than 40 C. but less than 10 C.

3. The sound damping article of claim 1, wherein the Compound Tan Delta Peak Temperature is at least 10 C.

4. The sound damping article of claim 1, wherein the tackifier has a softening point ranging from about 80 C. to about 150 C. according to ASTM 6493.

5. The sound damping article of claim 1, wherein the tackifier has a weight average molecular weight ranging from about 400 to about 3,500.

6. The sound damping article of claim 1, wherein the tackifier comprises a saturated cyclo-aliphatic amorphous hydrocarbon resin.

7. The sound damping article of claim 1, wherein the tackifier is present in an amount ranging from about 20 parts by weight to about 200 parts by weight, per 100 parts by weight of the styrenic block copolymer.

8. The sound damping article of claim 1, wherein the tackifier is present in an amount ranging from about 20 parts by weight to about 50 parts by weight, per 100 parts by weight of the styrenic block copolymer.

9. The sound damping article of claim 1, wherein the compound further comprises at least one additive selected from the group consisting of adhesion promoters; biocides; anti-fogging agents; anti-static agents; blowing and foaming agents; bonding agents and bonding polymers; dispersants; filler; flame retardants and smoke suppressants; impact modifiers; initiators; lubricants; micas; pigments, colorants and dyes; processing aids; release agents; silanes, titanates and zirconates; slip and anti-blocking agents; stabilizers; stearates; ultraviolet light absorbers; viscosity regulators; waxes; and combinations of any of the aforementioned additives.

10. The sound damping article of claim 1, wherein the compound is essentially free of styrene-(ethylene-ethylene/propylene)-styrene block copolymer and low vinyl styrene-(ethylene/butylene)-styrene block copolymer.

11. The sound damping article of claim 1, wherein the styrenic block copolymer is selected from at least one of hydrogenated styrene-isoprene-styrene block copolymer with hydrogenated vinylic isoprene midblock and high vinyl styrene-(ethylene/butylene)-styrene block copolymer.

12. The sound damping article of claim 11, wherein the sound damping article, in response to a noise stimulus, produces an effective sound pressure level according to IEC 711 that is at least 80% lower than an effective sound pressure level according to IEC 711 produced by a control article in response to the same noise stimulus, wherein the control article is formed from a control TPE compound that is identical in composition to the thermoplastic elastomer compound except that the control TPE compound is free of high softening point tackifier.

13. A loudspeaker system comprising at least one speaker driver, wherein at least a portion of the speaker driver is at least partially surrounded by at least a portion of the sound damping article of claim 1.

14. A loudspeaker system comprising a housing, at least one speaker driver at least partially contained in the housing, and a gasket positioned between at least a portion of the housing and at least a portion of the speaker driver, wherein the gasket comprises the sound damping article of claim 1.

15. Wired headphones or earphones comprising a cable, the cable comprising a conductive core at least partially enveloped by a jacket or insulation or both wherein at least one of the jacket or insulation comprises the sound damping article of claim 1.

Description

EXAMPLES

(1) Non-limiting examples of thermoplastic elastomer compounds of various embodiments of the present invention are provided.

(2) Examples Showing Effect of High Softening Point Tackifier

(3) Table 2a below shows sources of ingredients for the thermoplastic elastomer compounds of Examples 1 to 14 and Comparative Example A.

(4) TABLE-US-00002 TABLE 2a Chemical Brand Source Hydrogenated styrene-isoprene- HYBRAR 7135 Kuraray styrene block copolymer with hydrogenated vinylic isoprene midblock High vinyl styrene-(ethylene/ KRATON MD6958 Kraton butylene)-styrene block copolymer (Very high molecular weight) Styrene-(ethylene/butylene)- KRATON G1650 Kraton styrene block copolymer (Low molecular weight) Styrene-(ethylene/butylene)- KRATON G1651 Kraton styrene block copolymer (High molecular weight) White mineral oil 380 vis USP white oil (numerous) Hydrocarbon resin PLASTOLYN R1140 Eastman Chemical Polyethylene resin DOWLEX 2035 Dow Chemical Calcium carbonate VICRON 25-11 Specialty (limestone) Minerals Wax KEMAMIDE E PMC Biogenix Antioxidant IRGANOX 1010 BASF

(5) Table 2b below shows the formulations and certain properties of Examples 1 to 4 and Comparative Example A.

(6) TABLE-US-00003 TABLE 2b Example A 1 2 Ingredient Parts Wt. % Parts Wt. % Parts Wt. % HYBRAR 7135 100 38.26 100 35.54 100 33.18 380 vis USP white oil 80 30.60 80 28.43 80 26.54 PLASTOLYN R1140 0 0 20 7.11 40 13.27 DOWLEX 2035 40 15.30 40 14.21 40 13.27 VICRON 25-11 40 15.30 40 14.21 40 13.27 KEMAMIDE E 0.7 0.27 0.7 0.25 0.7 0.23 IRGANOX 1010 0.7 0.27 0.7 0.25 0.7 0.23 TOTAL 261.4 100.00 281.4 100.00 321.4 100.00 Tan Delta Peak Height 0.20 0.27 0.45 (unitless) Compound Tan Delta (Not available) (Not available) 5 Peak Temperature (deg C.) Example 3 4 Ingredient Parts Wt. % Parts Wt. % HYBRAR 7135 100 31.11 100 29.29 380 vis USP white oil 80 24.89 80 23.43 PLASTOLYN R1140 60 18.67 80 23.43 DOWLEX 2035 40 12.45 40 11.72 VICRON 25-11 40 12.45 40 11.72 KEMAMIDE E 0.7 0.22 0.7 0.21 IRGANOX 1010 0.7 0.22 0.7 0.21 TOTAL 321.4 100.00 321.4 100.00 Tan Delta Peak Height 0.75 0.95 (unitless) Compound Tan Delta 10 20 Peak Temperature (deg C.)

(7) Table 2c below shows the formulations and certain properties of Examples 5 to 8.

(8) TABLE-US-00004 TABLE 2c Example 5 6 7 8 Ingredient Parts Wt. % Parts Wt. % Parts Wt. % Parts Wt. % KRATON MD6958 100 33.18 100 31.11 100 29.29 100 27.67 380 vis USP white oil 80 26.54 80 24.89 80 23.43 80 22.14 PLASTOLYN R1140 40 13.27 60 18.67 80 23.43 100 27.67 DOWLEX 2035 40 13.27 40 12.45 40 11.72 40 11.07 VICRON 25-11 40 13.27 40 12.45 40 11.72 40 11.07 KEMAMIDE E 0.7 0.23 0.7 0.22 0.7 0.21 0.7 0.19 IRGANOX 1010 0.7 0.23 0.7 0.22 0.7 0.21 0.7 0.19 TOTAL 301.4 100.00 321.4 100.00 341.4 100.00 361.4 100.00 Tan Delta Peak Height 0.65 0.70 0.85 0.85 (unitless) Compound Tan Delta 3 2 7 16 Peak Temperature (deg C.)

(9) Table 2c below shows the formulations and certain properties of Examples 9 to 14.

(10) TABLE-US-00005 TABLE 2c Example 9 10 11 Ingredient Parts Wt. % Parts Wt. % Parts Wt. % KRATON G1651 100 31.11 100 29.29 100 27.67 KRATON G1650 0 0 0 0 0 0 380 vis USP white oil 80 24.89 80 23.43 80 22.14 PLASTOLYN R1140 60 18.67 80 23.43 100 27.67 DOWLEX 2035 40 12.45 40 11.72 40 11.07 VICRON 25-11 40 12.45 40 11.72 40 11.07 KEMAMIDE E 0.7 0.22 0.7 0.21 0.7 0.19 IRGANOX 1010 0.7 0.22 0.7 0.21 0.7 0.19 TOTAL 321.4 100.00 341.4 100.00 361.4 100.00 Tan Delta Peak Height 0.45 0.55 0.65 (unitless) Compound Tan Delta 1 2 13 Peak Temperature (deg C.) Example 12 13 14 Ingredient Parts Wt. % Parts Wt. % Parts Wt. % KRATON G1651 0 0 0 0 0 0 KRATON G1650 100 27.67 100 29.29 100 31.11 380 vis USP white oil 80 22.14 80 23.43 80 24.89 PLASTOLYN R1140 100 27.67 80 23.43 60 18.67 DOWLEX 2035 40 11.07 40 11.72 40 12.45 VICRON 25-11 40 11.07 40 11.72 40 12.45 KEMAMIDE E 0.7 0.19 0.7 0.21 0.7 0.22 IRGANOX 1010 0.7 0.19 0.7 0.21 0.7 0.22 TOTAL 361.4 100.00 341.4 100.00 321.4 100.00 Tan Delta Peak Height 0.75 0.55 0.45 (unitless) Compound Tan Delta 25 24 21 Peak Temperature (deg C.)

(11) Examples of Sound Damping TPE Compounds

(12) Table 3a below shows sources of ingredients for the thermoplastic elastomer compounds of Examples 15 to 19, which can be useful for sound and/or noise damping end-use applications.

(13) TABLE-US-00006 TABLE 3a Chemical Brand Source Styrene-(ethylene/butylene)- SEPTON 8004 Kuraray styrene block copolymer Hydrogenated styrene-isoprene- HYBRAR 7125 Kuraray styrene block copolymer with hydrogenated vinylic isoprene midblock High vinyl styrene- KRATON G1642 Kraton (ethylene/butylene)- styrene block copolymer (Low molecular weight) White mineral oil 550 vis USP white oil (numerous) Polyphenylene ether LXR 040C Bluestar New Chemical Materials Hydrocarbon resin PLASTOLYN R1140 Eastman Chemical Polypropylene D036W6 Braskem Wax KEMAMIDE E PMC Biogenix Antioxidant IRGAFOS 168 BASF Antioxidant IRGANOX 1010 BASF

(14) Table 3b below shows the formulations and certain properties of Examples 15 to 19.

(15) TABLE-US-00007 TABLE 3b Example 15 16 17 Ingredient Parts Wt. % Parts Wt. % Parts Wt. % SEPTON 8004 17 18.56 17 18.56 17 16.73 HYBRAR 7125 30 32.75 20 21.83 30 29.53 KRATON G1642 0 0 0 0 0 0 550 vis USP white oil 10 10.92 10 10.92 10 9.84 LXR 040C 20 21.83 20 21.83 20 19.69 PLASTOLYN R1140 10 10.92 20 21.83 20 19.69 D036W6 4 4.37 4 4.37 4 3.94 KEMAMIDE E 0.3 0.33 0.3 0.33 0.3 0.30 IRGAFOS 168 0.15 0.16 0.15 0.16 0.15 0.15 IRGANOX 1010 0.15 0.16 0.15 0.16 0.15 0.15 TOTAL 91.6 100.00 91.6 100.00 101.6 100.00 Hardness (Shore A) 52 51 52 Tensile (psic) 1400 1340 1110 Elongation (%) 410 430 440 Noise Reduction (%) >80 >80 >80 Example 18 19 Ingredient Parts Wt. % Parts Wt. % SEPTON 8004 17 15.80 0 0 HYBRAR 7125 30 27.88 0 0 KRATON G1642 0 0 47 41.01 550 vis USP white oil 10 9.29 10 8.73 LXR 040C 20 18.59 20 17.45 PLASTOLYN R1140 20 18.59 20 17.45 D036W6 10 9.29 17 14.83 KEMAMIDE E 0.3 0.28 0.3 0.26 IRGAFOS 168 0.15 0.14 0.15 0.13 IRGANOX 1010 0.15 0.14 0.15 0.13 TOTAL 107.6 100.00 114.6 100.00 Hardness (Shore A) 66 65 Tensile (psic) 1540 1830 Elongation (%) 460 600 Noise Reduction (%) >80 >80

(16) Without undue experimentation, those having ordinary skill in the art can utilize the written description of the present invention, including the Examples, to formulate thermoplastic elastomer compounds and articles formed therefrom which exhibit useful vibration damping properties while also exhibiting beneficial sound and/or noise damping properties at or above room temperature.

(17) All documents cited in the Embodiments of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention.

(18) While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of the present invention.