Exxonmobil Chemical Patents Inc.

Advanced Elastomer Systems, L.p.

Norman Glenn Barber

Tonson Abraham

Kuo-Shein Shen

Edward John Blok

Trazollah Ouhadi

Sabet Abdou-Sabet

In one or more embodiments of this invention, TPE compositions having between 55 and 85 Shore A hardness and having good adhesion to metal substrates, are produced by blending an amount of unsaturated carboxylic acid functionalized thermoplastic resin with a very soft TPV, namely, a TPV base having a hardness of 45 Shore A or less.

Adhesive thermoplastic vulcanizates

Thermoplastic vulcanizate compositions having good adhesion to unheated polar substrates include an amount of functionalized polyolefin that comprises greater than 80% of the total polyolefin of the TPV. The functional group may be an anhydride. Exemplary TPVs may further include polyamide, and an elastomer, which may include one or more of conjugated diene rubber, unsaturated styrenic triblock copolymer rubber, hydrogenated styrenic triblock copolymer rubber, ethylene/alpha-olefin rubber, and ethylene/alpha-olefin/non-conjugated diene rubber. The TPVs may have hardness values of less than 85 Shore A and peel forces with respect to unheated polar substrates of greater than 15 pli. Articles comprising polar substrates and TPVs are also taught.

Thermoplastic vulcanizates having improved adhesion to polar substrates

Provided in one aspect is a method of melt blending comprising providing an extruder possessing addition points from a zero point to a 100 point the length of the extruder; adding at least one thermoplastic and at least one curable polymer at the zero to 10 point of the extruder; adding at least one silicone hydride at the 5 to 30 point of the extruder; adding at least one metal catalyst at the 20 to 60 point of the extruder, with the proviso that the metal catalyst is added at least 5 points farther down the extruder than the silicone hydride. Provided in another aspect is a hydrosilylation curative composition comprising a silicone hydride having the formula wherein H is hydrogen, and each R' is independently selected from hydrogen and Cto Calkyl groups; R&#x2033; is selected from Cto Calkyl groups; n is an integer from 5 to 45; and m is an integer from 5 to 45.

Method of melt blending curable polymer compositions using silicone hydrides

A thermoplastic vulcanizate comprising a dynamically-cured rubber, where the rubber is selected from the group consisting of ethylene-propylene-non-conjugated diene rubber, propylene-based rubbery copolymers with units derived from non-conjugated diene monomers, and butyl rubber, where dynamic vulcanization is effected with a phenolic resin or a silicon-containing curative, and where the rubber is dynamically cured to an extent where greater than 94% by weight of the rubber is insoluble in cyclohexane at 23&#xb0; C., and from about 25 to about 250 parts by weight of a thermoplastic polymer phase per 100 parts by weight rubber, where from about 75% to about 100% by weight of said thermoplastic polymer phase includes a butene-1-based polymer.

Thermoplastic vulcanizates with low compression set

The compression set [(70&#xb0; C., 22 hr), (100&#xb0; C., 22 hr)] of TPVs can be improved by substituting, within their respective constituent plastic phase, all or portions of polyolefins having a high melting point, with polyolefins having lower melting point (Tm from between 115&#xb0; C. to 140&#xb0; C.). Exemplary polyolefins having melting points in this range include homopolyethylene, syndiotactic polypropylene, and isotactic poly(1-butene). Composition and methods of formulating thermoplastic vulcanizates to achieve an improved high temperature (between 70&#xb0; C. 100&#xb0; C.) compression set by selecting between suitable polyolefins on the basis of melting point temperature and substituting from 30% to 100% of high melting point polyolefins with low melting point polyolefins in the plastic phase are taught.

Method for improving compression set in thermoplastic vulcanizates

This invention relates to a soft thermoplastic vulcanizate composition comprising: a) from about 2-10 wt %, based upon total polymer content weight a)+b)+c), of a thermoplastic polyethylene or polypropylene homopolymer, or ethylene-propylene copolymer, or copolymer that includes ethylene or propylene together with one or more Cto C&#x3b1;-olefins, said thermoplastic having at least 25% crystallinity by DSC; b) from about 15 to about 36 wt. %, based upon total polymer content weight a)+b)+c), of an ethylene-&#x3b1;-olefin random or block copolymer thermoplastic having less than 5% crystallinity by DSC; c) from about 60 to about 80 wt. %, based upon total polymer content weight a)+b)+c), of a cross-linked elastomer; and d) from about 50 to about 65 wt %, based upon total composition weight a)+b)+c)+d), of a process oil; wherein said thermoplastic vulcanizate composition has a Shore A Hardness of less than 35. The invention compositions may also comprise from about 0 to about 40 wt. %, based upon the total composition weight, of conventional additives.

Soft thermoplastic elastomers

A blend of an EPDM made with VNB instead of ENB and specified melt viscosity reducers is imbued with a unique ability to form a processable blend with a polyolefin phase in which PE is present in a major amount by weight relative to PP. In the substantially fully cured vulcanizate (TPV) of the blend the ratio of PE to pEPDM is in the range from more than 1:3 up to about 1:0.6. This blend is made processable with less than 200 phr of a processing oil in presently available commercial processing equipment by using an inert melt viscosity reducer which is compatible with the pEPDM and PE phases without being substantially miscible in either. A preferred melt viscosity reducer is chosen from (a) a polyolefin selected from the group consisting of isotactic poly(1-butene), ethylene-co-1-butene, propene-co-1-butene and ethylene-co-propene-co-1-butene; (b) oils and waxes having a solubility parameter in the range from about 19.5 to 21.5; and (c) a block copolymer of a fatty acid and polyethylene oxide having a melting point lower than 150&deg; C.

Processable polyethylene/EPDM thermoplastic vulcanizates

Low oil swell, non sticky readily processable carboxylated nitrile rubber-thermoplastic polyurethane vulcanizate compositions have increased upper service temperature over comparable thermoplastic polyurethanes. The compositions of the present invention are made utilizing a processing aid, for example, maleated polyolefins and addition type curing agents such as bisoxazolines or bisimidazolines. The compositions generally contain thermoplastic polyurethane as a continuous phase with the carboxylated nitrile rubber being dispersed therein.

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Norwalk, OH, United States of America

Norman Glenn Barber