TIRE WITH BORON NITRIDE REINFORCED POLYURETHANE

Abstract

This invention relates to a vehicular tire containing at least one boron nitride reinforced polyurethane component. The polyurethane component is a cast polyurethane containing a dispersion of a layered hexagonally crystalline boron nitride (h-BN) particles. The polyurethane is the product of a castable liquid polyurethane reaction mixture derived from polyisocyanate and polymeric polyols without containing carbon-to-carbon bonds as distinguished from carbon-to-carbon double bond containing millable, sulfur curable, polyurethanes. It may sometimes be referred to as being a cast polyurethane.

Claims

1. (canceled)

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

9. (canceled)

10. (canceled)

11. (canceled)

12. (canceled)

13. (canceled)

14. (canceled)

15. (canceled)

16. A method of preparing a particulate layered hexagonally crystalline boron nitride (h-BN) reinforced polyurethane which comprises: (A) preparing a polyurethane reaction mixture by: (1) blending h-BN with polymeric polyol comprised of at least one of polyether polyol and polyester polyol to form a composite thereof. followed by blending an organic diisocyanate with said composite, or (2) blending h-BN with an isocyanate terminated pre-polymer of organic diisocyanate and polymeric polyol comprised of at least one of polyether polyol and polyester polyol to form a composite thereof, followed by blending a primary aliphatic diamine with said composite, and (B) allowing said polyurethane reaction mixture to react to from a polyurethane product containing a dispersion of h-BN reinforcement, wherein said polymeric polyol is free of carbon-to-carbon double bonds.

17. The method of claim 16 which comprises preparing a polyurethane reaction mixture by blending said h-BN with polymeric polyol comprised of at least one of polyether polyol and polyester polyol to form a composite thereof. followed by blending an organic diisocyanate with said composite and allowing said polyurethane reaction mixture to react to from a polyurethane product containing a dispersion of h-BN reinforcement.

18. The method of claim 17 which comprises preparing a polyurethane reaction mixture by blending said h-BN with an isocyanate terminated pre-polymer of organic diisocyanate and polymeric polyol comprised of at least one of polyether polyol and polyester polyol to form a composite thereof, followed by blending a primary aliphatic diamine with said composite, and allowing said polyurethane reaction mixture to react to form a polyurethane product containing a dispersion of h-BN reinforcement.

19. The method of claim 16 which comprises casting said polyurethane reaction mixture into a suitable mold cavity and allowing said polyurethane reaction mixture to react to form a polyurethane containing a dispersion of said h-BN comprised of at least one of a tire and tire with a component thereof.

20. (canceled)

Description

EXAMPLE I

[0048] Polyurethane reaction mixtures are prepared to evaluate an inclusion of a dispersion of particulate h-BN in a polyurethane from a polyurethane reaction mixture comprised of polymeric polyester polyol and polyisocyanate.

[0049] For the h-BN containing polyurethane, the polymeric polyester polyol was blended with the h-BN, dry molecular sieve desiccant (to promote moisture removal) and dioctyladipate plasticizer (to reduce viscosity of the blend). The resulting blend was degassed under vacuum to remove any residual moisture. The polyisocyanate is separately degassed under vacuum.

[0050] The blend was then blended with the polyisocyanate (MDI) to form a polyurethane reaction mixture which was cast into a suitable mold and the polyurethane reaction mixture allowed to react to form a molded (shaped) h-BN reinforced polyurethane sample.

[0051] For this evaluation, a control sample of polyurethane reaction mixture was prepared comprised of reacting a liquid reaction mixture without the h-BN comprised of polymeric polyester polyol (together with molecular sieve desiccant) and polyisocyanate and to form a polyurethane product.

[0052] Experimental rubber Samples B through F were prepared with the polymeric polyol and polyisocyanate of control rubber Sample A (together with the molecular sieves desiccant) together with from 2 to 5 parts of the particulate h-BN having been added to the polymeric polyol. The h-BN was blended with the polymeric polyol together with the desiccant of molecular sieves prior to adding the polyisocyanate to form the polyurethane reaction mixture.

[0053] The components of the polyurethane reaction mixture are reported in the following Table 1 in terms of parts by weight per 100 parts by weight of the polyurethane (polymeric polyol and diisocyanate), (php), unless otherwise indicated.

TABLE-US-00001 TABLE 1 Parts by weight per 100 parts of Polyurethane* Control Experimental Material A B C D E F Polyurethane.sup.1 100 100 100 100 100 100 Molecular sieves.sup.2 0.33 0.33 0.33 0.33 0.33 0.33 Dioctyladapate.sup.3 0 0 0 0 0 5.8 Boron nitride, hexagonal(h-BN).sup.4 0 1.3 1.9 2.6 3.2 1.3 *parts by weight per 100 parts by weight of combination of polymeric polyol plus diisocyanate .sup.1Product of 63.69 parts of polymeric polyester polyol and 36.31 parts of diisocyanate. The polymeric polyester polyol was a viscous liquid as Elastocast ™ 72580R from BASF. The diisocyanate was MDI as Lupranate ™ 5030 from BASF. .sup.2Dried molecular sieves, a white powder, from the Alfa Aesar Company .sup.3Plastizer from Sigma Aldrich .sup.4White fluffy powder from Momentive

[0054] The following Table 2 illustrates physical properties of the polyurethanes of the Control Sample A and Experimental Samples B through F based upon the basic formulation of Table 1.

TABLE-US-00002 TABLE 2 Control Experimental Properties A B C D E F Shore A hardness (23° C.) 70 72 73 74 74 70 Modulus (300%), MPa 6 5.8 6.8 5.7 6 5 Tensile strength, MPa 14 23 26 25 24 20 Elongation, at break (%) 463 477 592 644 609 625 Grosch abrasion rate.sup.1, (high 315 305 325 347 348 320 severity test, gm/km) Tear strength.sup.2, (N/mm) 58 60 61 63 63 56 .sup.1The Grosch abrasion rate, reported in terms of mg/km, can be run on a LAT-100 Abrader and is measured in terms of mg/km of polyurethaner abraded away. The test polyurethane sample is placed at a slip angle under constant load (Newtons) as it traverses a given distance on a rotating abrasive disk (disk from HB Schleifmittel GmbH). In practice, a low abrasion severity test may be run, for example, at a load of 20 Newtons, 2° slip angle, disk speed of 40 km/hr for a distance of 7,500 meters; a medium abrasion severity test may be run, for example, at a load of 40 Newtons, 6° slip angle, disk speed of 20 km/hr and distance of 1,000 meters; a high abrasion severity test may be run, for example, at a load of 70 Newtons, 12° slip angle, disk speed of 20 km/hr and distance of 250 meters; and an ultra-high abrasion severity test may be run, for example, at a load of 70 Newtons, 16° slip angle, disk speed of 20 km/hr and distance of 500 meters. .sup.2Data obtained according to a tear strength (peal adhesion), or tear resistance test, ASTM test D624

[0055] From Table 2 it can be seen that the tensile strength property of the polyurethanes of Experimental Samples G through E progressively beneficially increased by the progressive increase of the addition of the h-BN as compared to the polyurethane of Control Sample A without the h-BN addition.

[0056] For the polyurethane of Experimental Sample F, the tensile strength also significantly increased over the tensile strength of the Control Sample A, although to a lesser extent than the tensile strength of Experimental Samples B through E, apparently because of the significant addition of the dioctyladipate plasticizer.

[0057] While the beneficial increase of tensile strengths of the polyurethanes may not be completely understood, it is envisioned that the nitrogen atoms of the h-BN can undergo a hydrogen bonding with hydrogen atoms contained on the polyurethane to thereby promote a beneficial reinforcement of the polyurethanes.

EXAMPLE II

[0058] Additional polyurethane reaction mixtures are prepared to evaluate an inclusion of a dispersion of particulate h-BN in a polyurethane reaction mixture comprised of primary diamine (sodium chloride salt thereof and therefore a chemically blocked diamine) and pre-polymer comprised of polyisocyanate terminated polymeric polyester polyol.

[0059] The polymeric polyester polyol containing the h-BN (without molecular sieve desiccant) was degassed under vacuum to remove any residual trapped air and the reaction mixture cast into a suitable mold and allowed to react (upon being initially heated to unblock the primary amine reactant) to form a molded (shaped) polyurethane product containing a dispersion of h-BN reinforcement.

[0060] For this evaluation, a Control Sample was prepared comprised of reacting a liquid reaction mixture comprised of primary diamine and isocyanate terminated pre-polymer of polyisocyante and polymeric polyester polyol without h-BN to form a polyurethane product.

[0061] Experimental rubber Samples A through H were prepared comprised of the primary diamine and pre-polymer of the Control Sample but with added h-BN in amounts ranging from 2 to 5 parts by weight of the particulate h-BN. The h-BN was blended with the primary diamine.

[0062] The polyurethane is referred to as being “hot cast” in a sense of heating to activate the primary diamine reactant.

[0063] The components of the polyurethane reaction mixture are reported in the following Table 3 in terms of weight percent of the polyurethane of the polyurethane containing product unless otherwise indicated.

TABLE-US-00003 TABLE 3 Hot Cast Polyester Urea System Reaction Mixture (Parts by weight per 100 parts Polyurethane)* Material Control A B C D E F G H Polyurethane.sup.6 100 100 100 100 100 100 100 100 100 Dioctyladipate.sup.7 0 4.1 4.1 4.1 4.1 4.1 4.1 4.1 4.1 Boron nitride, hexagoneal (h-BN).sup.8 0 0 0.23 0.45 0.68 0.9 1.1 1.4 4.5 *Polyurethane component as diamine reacted with isocynate terminated polyol .sup.6100 parts by weight polyurethane (polyureaurethane) as a product of 90.22 parts by weight isocyanate terminated polyester polyol and 9.78 parts by weight primary diamine. The isocyanate terminated polymeric polyester polyol is provided as Duracast S700 ™, a viscous liquid product from Chemtura Corporation. The primary diamine curative is provided as Duracure C.sub.3LF ™ from Chemtura Corporation. .sup.7Plasticizer from Sigma Aldrich .sup.8White fluffy powder obtained from Momentive

[0064] The following Table 4 illustrates physical properties of the polyurethanes of the Control Sample and Experimental Samples A through H based upon the basic formulation of Table 3.

TABLE-US-00004 TABLE 4 Hot Cast Polyester Urea System Properties Polyester Urea Property Control A B C D E F G H Shore A hardness (23° C.) 72 70 71 71 71 67 68 70 72 Modulus (300%), MPa 4.4 4.1 4.1 4.2 4.1 4 4.4 4.4 4.2 Tensile strength, (MPa) 14.2 15.7 15.2 17.2 18.2 16.2 13.8 18.4 19 Elongation at break (%) 922 995 955 903 998 899 785 834 964 Grosch abrasion rate (high severity test) (mg/km) 928 354 362 384 381 353 471 416 453 Tear strength, N/mm 59 60 58 56 56 53 55 55 55

[0065] From Table 4 it can be seen that that the tensile strength property of the polyurethane products of Experimental Samples B through E, as well as G and H, progressively beneficially increased by the progressive increase of the addition of the h-BN as compared to the polyurethane product of the Control Sample without the h-BN addition. It is noted that the Grosch abrasion rate was also beneficially reduced as compared to the Control Sample.

[0066] For the polyurethane product of Experimental Sample A, also without an addition of h-BN, the tensile strength beneficially increased, as well as Grosch Abrasion rate being beneficially reduced, perhaps due to the miniscule addition of the dioctyladipate plasticizer which might have undergone a degree of hydrogen bonding with the polyurethane.

[0067] For the polyurethane of Experimental Sample F, both the tensile strength and elongation properties were reduced as compared to the Control Sample. While the cause is unknown, it is believed likely than a small amount of air (for example, a small air bubble) may have been present in the polyurethane mixture to thereby prevent its optional polyurethane formation.

[0068] While the beneficial increase of tensile strengths, as well as the beneficial reduction in Grosch abrasion rates of the polyurethanes, may not be completely understood, it is envisioned that the nitrogen atoms of the h-BN can undergo a hydrogen bonding with hydrogen atoms contained on the polyurethane to thereby promote a beneficial reinforcement of the polyurethane.

[0069] Therefore, it is concluded that the addition of the h-BN to the polyurethane reaction mixtures in both Examples I and II resulted in a beneficial promotion of reinforcement of the polyurethanes.

[0070] While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants' general inventive concept.