Shell Oil Comapny

Steven S Chin

Bridget A Spence

Ronald J Hoxmeier

Glenn R Himes

Jeffrey G Southwick

David J St Clair

Dale Lee Handlin, Jr

Vahid Sendijarevic

Michael A Masse

Aisa Sendijarevic

Carl Lesley Willis

Kurt C Frisch

David Romme Hansen

Ramsis Gobran

Craig A Stevens

John A Miller

Hector Hernandez

Kurt Charles Frisch

Jozef Lucien Cenens

Richard L Talbott

Ronald J Hoximeier

Thermoplastic polyurethanes are formed from a hydrogenated polydiene diol having from 1.6 to 2 terminal hydroxyl groups per molecule and a number average molecular weight between 500 and 20,000, an isocyanate having two isocyanate groups per molecule, and optionally a chain extender having two hydroxyl groups per molecule. The thermoplastic polyurethanes have excellent resistance to moisture as evidenced by retention of more than 70%, preferably at least 85%, of original tensile strength after aging in water for 7 days at a temperature of at least 70.degree. C. Preparation by a prepolymer method with subsequent addition of the chain extender is preferred.

Polyurethanes having improved moisture resistance

Cast polyurethanes are preferably formed from a hydrogenated polydiene diol having from up to 2 terminal hydroxyl groups per molecule and a number average molecular weight between 1000 and 20,000, an isocyanate having two or more isocyanate groups per molecule. This composition is then reacted with an amine curing agent at 80 to 130.degree. C. to form a cast elastomer with excellent hydrolytic stability. The amine curing agent must be a hindered aromatic amine crosslinker with low polarity and a solubility parameter of less than 10.5.

Cast polyurethane elastomers containing low polarity amine curing agents

Radial or star asymmetric block copolymer of the following formulae and improved adhesive and sealant compositions containing them

Dissimilar arm asymmetric radial or star block copolymers for adhesives

A low viscosity adhesive composition which comprises:

Low viscosity adhesive compositions containing asymmetric radial polymers

Radial or star asymmetric block copolymer of the following formulae and an improved tape assembly using the copolymers and improved adhesive and sealant compositions containing them (I) (A--HD).sub.x --Y--(UD).sub.z or (II) (UD--A--HD).sub.x --Y or (lII) ((UD).sub.y --A--HD).sub.x --Y-(UD).sub.z wherein A is a vinyl aromatic hydrocarbon block having a molecular weight of from 4000 to 20,000, HD is a hydrogenated conjugated diene block having a molecular weight of from 10,000 to 100,000, Y is a multifunctional coupling agent, UD is a partially hydrogenated conjugated diene block having a molecular weight of from 1000 to 80,000, x is an integer from 2 to 30, y is 0 or 1, z is an integer from 1 to 20, and x+z ranges from 3 to 30.

Dissimilar arm asymmetric radical or star block copolymers for adhesives

A process is disclosed for producing six-armed and eight-armed asymmetric radial block copolymers. The process comprises anionically polymerizing a diene and/or a vinyl aromatic hydrocarbon to create living polydiene and/or vinyl aromatic hydrocarbon arms, sequentially anionically polymerizing a vinyl aromatic hydrocarbon and a diene to create living block copolymer arms and coupling the two sets of arms together in one step with a coupling agent that will couple six or eight arms, wherein the molar ratio of the vinyl aromatic hydrocarbon-diene arms to the polydiene arms is sufficient to produce a statistical blend with less than 5 weight percent homopolydiene.

Method for producing statistically coupled asymmetric radial polymers

A method for preparing asymmetric radial polymers wherein the different polymeric arms are contacted sequentially with a coupling agent. The method narrows the relative arm distribution of the several asymmetric radial polymers produced and significantly increases the amount of total product having the desired ratio of polymeric arms. Any coupling agent known in the prior art to be useful in the production of asymmetric radial polymers may be used in the method of this invention but coupling agents having from three to about twelve functional groups are most effective.

Method for preparing asymmetric radial copolymers having two first arms

A linear styrene-isoprene-styrene block copolymer composition comprised of linear polymeric blocks wherein the block copolymer composition has a coupling efficiency of 25 to 82 percent, a polystyrene content of from 19 to 27 percent by weight, a polystyrene block molecular weight (peak polystyrene equivalent molecular weight as determined by gel permeation chromatography) of 12,000 to 18,000, and an overall molecular weight (peak polystyrene equivalent molecular weight as determined by gel permeation chromatography) of from 170,000 to 280,000. The invention also contemplates adhesive formulations comprising these block copolymer compositions and a tackifying resin.

Styrene-isoprene-styrene block copolymer composition and adhesives made

The present invention provides a method for making a method for making high service temperature rubber compound, hot melt adhesive or sealant compositions by combining a polyphenylene ether resin with an elastomeric block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene, which comprises (a) making a masterbatch of 2 to 50 phr of a polyphenylene ether having an intrinsic viscosity of 0.3 deciliters per gram or more and 100 phr of said block copolymer by extruding them together with 2 to 30 phr of an endblock compatible resin, and (b) optionally mixing the masterbatch with more of the block copolymer.

Polyphenylene ether/thermoplastic elastomer block copolymer blends for

Method for preparing asymmetric radial copolymers having four first arms

A process for preparing a coupled asymmetric block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene which comprises: (a) adding sufficient anionic polymerization initiator to the vinyl aromatic hydrocarbon monomer to start polymerization of the vinyl aromatic hydrocarbon, (b) polymerizing the vinyl aromatic hydrocarbon for a time sufficient to form a first set of vinyl aromatic hydrocarbon blocks having a desired molecular weight, (c) adding sufficient anionic polymerization initiator to start polymerization of a second set of vinyl aromatic hydrocarbon blocks, (d) completing the polymerization of the vinyl aromatic hydrocarbon for a time such that the first set of vinyl aromatic hydrocarbon blocks continues to grow to the desired molecular weight and the second set of vinyl aromatic hydrocarbon blocks grows to a desired smaller molecular weight, (e) adding a conjugated diene and polymerizing it on the ends of the vinyl aromatic hydrocarbon blocks for a time sufficient to form vinyl aromatic hydrocarbon-conjugated diene arms of the desired molecular weight, and (f) adding a coupling agent and coupling the arms to form the asymmetric block copolymer.

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Houston, TX, United States of America

Steven S Chin