Invented by Mark Arigo, Terri Roxanne Carvagno, Jacobus Gillis de Hullu, Sebastian Finger, Hubert Hirschlag, Janine Klomp, Fabian Peters, Carla Recker, Christopher George Robertson, Peter Versluijs, Continental AG, Continental Reifen Deutschland GmbH, Synthomer Adhesive Technologies LLC
The Continental AG, Continental Reifen Deutschland GmbH, Synthomer Adhesive Technologies LLC invention works as followsModified thermoplastic hydrocarbon resins, methods for their production and applications in rubber compositions are disclosed. Modified thermoplastic polymers are made by reducing the amount of dimer, trimer oligomers and tetramer oligomers in comparison to their unmodified counterparts. This results in a modified thermoplastic polymer that has a larger shift in glass transition temperatures of the elastomers used in tire formulations. This results in better viscoelastic indicators of tire tread performance such as wet traction and rolling resistance. Modified thermoplastic resins have remarkable properties that can be applied to various rubber compositions such as brakes, tires, belts and hoses. The modified thermoplastics in automobile tires are shown to have excellent results when it comes to balancing rolling resistance, tire wear and performance on snow.
Background for Modified resins, and their uses
Hydrocarbon resins and thermoplastic natural resins are used to modify viscoelastic characteristics of rubber compositions. These rubber compositions include tire tread compounds. This allows tire tread properties (such a wet grip or rolling resistance) to be improved. Resins are also used to improve the tack of tire tread compounds and reduce their viscosity.
Rubber mixtures, especially those for tire treads, are becoming more and more resin-based. U.S. Patent Application Publication No. Tire treads that contain thermoplastic resins at levels greater than 50 phr are disclosed in 2016/0222197. “A good compatibility between thermoplastic and rubber is required to achieve high thermoplastic loadings in polymer matrix.
The current thermoplastic technology for tires uses high-glass transition thermoplastics to modify rubber glass transition temperatures Tg and viscoelastic characteristics to improve the balance of wet grip performance and rolling resistance performance. “The introduction of thermoplastics will affect other tire properties such as rolling resistance, wear and wet grip. This must be balanced against the wet grip performance.
Hydrocarbon resins thermoplastic are mixed with elastomers and reinforcing particles to create the rubber compounds that go into the manufacture of automobile tires. It is crucial that the thermoplastic and elastomer are blended in a single phase to maximize the effect of the thermoplastic on the viscoelastic characteristics of the elastomer. Thermoplastic resins are used in tire tread applications to increase the glass-transition temperature (Tg), which results in a higher hysteretic loss of energy. This increase in hysteresis must be balanced with the requirement for low hysteresis properties of the compound at elevated temperatures to achieve low rolling friction (fuel-efficient) tires.
The ability of a resin to balance wet grip performance and rolling resistance in this manner depends on thermoplastic resin’s glass transition temperature (Tg), average number molecular mass (Mn), as well as molecular distribution. The molecular mass, Mn, is a major factor in determining the Tg of hydrocarbon thermoplastics. Low Tg thermoplastics are low in Mn. However, increasing Mn will increase the Tg of thermoplastic resins. Low molecular-weight thermoplastic species do not modify the elastomer Tg efficiently in a typical thermoplastic molecular-weight distribution because they have lower transition temperatures. The very high molecular-weight thermoplastic resins (characterized by their z average molecular mass, Mz), are also not effective because they are incompatible with the elastomers. The molecular mass is the current way to increase thermoplastic resin (Tg). However, this method is not effective because, under typical polymerization conditions the amount of high molecular-weight thermoplastic resin that is incompatible with elastomers increases as Mn increases.
It is desirable to obtain a thermoplastic modified resin with a high Tg and a low Mz in order to modify the elastomer composite Tg most effectively while maintaining compatibility to the rubber matrix.
Thermoplastic resin compositions modified by the present invention are provided.” The modification of thermoplastics by reducing the amount of oligomer in the modified resin as compared with a corresponding non-modified thermoplastic, where oligomers include dimer, trimer tetramer and/or pentamer monomer species used to produce modified thermoplastics, provides a higher ratio of glass transition temperature to z average molecular mass (Mz), than what is available today for corresponding commercial thermoplastics that are not modified. Modification of thermoplastics resins using the disclosed methods confers unexpected superior properties to products that incorporate such modified thermoplastics. Products such as tires, adhesives, molded polymers, belts and hoses possess superior properties compared to those without the disclosed modified resins. Also disclosed are methods for obtaining, creating, or manufacturing such modified thermoplastics resins as well as a variety of products that incorporate the disclosed modified resins.
The modified thermoplastics are selected from, for example: a modified pure monomer (PMR) thermoplastic resin, modified hydrogenated or partially hydrogenated pure monomer (PMR) thermoplastic resin, modified hydrogenated or partially hydrogenated C5/C9 thermoplastics, and a modification of the C9 thermoplastics. Modified thermoplastics can be selected from a variety of options, including: modified pure monomer thermoplastics, modified hydrogenated or partly hydrogenated pure monomer thermoplastics, hydrogenated/partially hydrogenated C5/C9 resins, hydrogenated/partially hydrogenated/modified C9 resins, hydrogenated/partially hydrogenated/modified C9 resins, hydrogenated/partially hydrogenated/dicyclopentadiene thermoplastics, DCPD resins
The present invention describes additional methods for manufacturing modified thermoplastics resins. These methods include polymerizing, or co-polymerizing, one or more unsaturated monomers (aliphatic or aromatic), terpenes or rosin acids, unsaturated monomers cycloaromatic or cycloaliphatic, unsaturated monomers cycloaliphatic or aromatic, methacrylates or unsaturated aromatic or vinyl monomers and reducing the oligomer content in the modified resin. The modified thermoplastic resins in these embodiments possess the properties of Formula I.
T10 is the temperature where the modified resin begins to lose about 10% of its mass as measured using high resolution TGA. Tmax is measured using high resolution TGA. In such embodiments the value S is greater or equal than 2 and less that 50,000 when Oligomer by GPC is determined, or greater or equal than 5 and less 10,000 when Oligomer by high resolution TGA is determined, and the value Mz is lower or equal than 9,000 g/mol.
The modified thermoplastics resins can be selected from, for example: a modified pure monomer (PMR) thermoplastic, modified hydrogenated or partially hydrogenated pure monomer (PMR) thermoplastic, modified hydrogenated or partially hydrogenated C5 thermoplastic, modified hydrogenated or partly hydrogenated C5/C9 thermoplastic, modified hydo- or p-hydrogenated C9 thermoplastic, modified dicyclopentadiene (DCPD), modified DCPD thermoplastic, modified Modified thermoplastics can be selected from, such as: modified pure monomer thermoplastics (PMR), modified hydrogenated (or partially hydrogenated) pure monomer thermoplastics (PMR), modified hydrogenated (or partially hydrogenated) C5 thermoplastics, hydrogenated (or partially hydrogenated) C5/C9 resins, hydrogenated (or partially hydrogenated) C9 resins, hydrogenated (or partially hydrogenated) dicyclopentadiene thermoplastics (DCPD), modified C5 thermo
TheClick here to view the patent on Google Patents.