Sika Technology Ag

Sika Corporation

Hong Yao

Steven Rosenberg

Norman Blank

Adrian Van Maurik

Hans Peter Tschan

Thomas Bove

Michael Schlumpf

Norman E Blank

Allison Carlson

An one-part polyurethane composition, including: A) 15-75 wt.-% of at least one isocyanate-functional polyurethane polymer; B) 5-30 wt.-% of at least one organic thixotropy agent; C) 2-25 wt.-% of at least one plasticizer having viscosity of less than 500 mPa s, measured at 0° C. with cone-plate viscosimeter, shear rate 10 s, cone angle 1°, spindle 25-2, and cone tip-plate distance of 0.05 mm; D) 0-15 wt.-% of at least one solvent; E) 0-50 wt.-% of at least one filler; F) at least one catalyst for curing of polyurethane compositions; wherein isocyanate-functional polyurethane polymer has NCO content in range of 0.8%-2.5% by weight and is obtained from reaction of methylene diphenyl diisocyanate (MDI) and polyol in NCO/OH ratio of at least 3/1 and subsequent removal of non-reacted MDI; and polyol has viscosity, measured according to ASTM D4878-15 at 25° C., of less than 2000 mPa s; and isocyanate-functional polyurethane polymer has remaining content of MDI of at most 0.5% by weight.

One-part polyurethane sealant for low temperature applications

A two-component composition is described which comprises A) an isocyanate component comprising an isocyanate-terminated urethane prepolymer, B) a water component comprising water, and at least one latent amine hardener in component A). The two-component composition of the invention is suitable as a sealant, in particular as a joint sealant. Particular advantages are that primerless application is possible with good adhesion, even at low temperatures, such as 4.4&#xb0; C. or below. The substrate to be sealed are preferably concrete substrates.

Two-component polyurethane sealant for application at low temperature

A one-part polyurethane composition includes the reaction product of at least one polyether polyol PO, at least one thermoplastic polyester polyol PE, at least one hydrophobic polyol PH, and at least one polyisocyanate PI, preferably methylene diphenyl diisocyanate (MDI), wherein the composition has a remaining isocyanate content of between 0.8 and 3.5 wt.-%, preferably between 1.4 to 1.8 wt.-%, based on the total weight of the isocyanate-functional polymers comprised therein, and wherein said polyether polyol PO includes a bifunctional polyether polyol PO1 and a trifunctional polyether polyol PO2 and wherein said hydrophobic polyol PH is a polyester polyol based on fatty acids. The inventive one-component composition exhibits high green strength and long open time, as well as high storage stability. It is especially suitable as adhesive, in particular for automotive windshields and is preferably applied warm.

One-part polyurethane adhesive with high green strength

A polyurethane adhesive which is useful in bonding porous and non-porous surfaces is provided. The adhesive is especially useful in bonding windshield glass into automotive frames under a variety of environmental conditions, particularly in after market windshield replacement applications. The polyurethane includes at least one urethane prepolymer which is based on at least one thermoplastic polyol. In one embodiment, the urethane prepolymer may be formed from one or more polyisocyanates, one or more polyetherpolyols and one or more thermoplastic polyesterpolyols, wherein the prepolymer has a free isocyanate content of from about 0.6 to about 3.5% by weight, based on the weight of the polyurethane. In another embodiment, a one-part adhesive composition is provided which includes an isocyanate-functional and thermoplastic polyurethane prepolymer having a free isocyanate content of from about 0.6 to about 3.5% by weight, based on the weight of the polyurethane, and a combination of several catalysts which are capable of catalyzing the reaction of isocyanate moieties with isocyanate-reactive moieties while providing less temperature dependent catalyzing of the reaction between isocyanate moieties and water. Also provided is a process for bonding two or more substrates together utilizing the polyurethane adhesive. In automotive windshield replacement applications, the polyurethane adhesive allows for a sufficient working time and development of green strength to provide a safe drive-away time within 1 hour at a temperature from about 0 to about 100&#xb0; C.

Polyurethane adhesive for windshield applications

An automotive windshield replacement method which includes: a) applying an adhesive to an automotive windshield and/or an automobile body substrate, said adhesive including at least one urethane prepolymer formed from reaction materials including: i) isophorone diisocyanate and/or 4,4'-diphenylmethanediisocyanate; ii) an ethylene oxide-end-capped triol having a weight average molecular weight of about 4500 to about 5000; and iii) hexanediol adipate; b) contacting the substrates together, within the working time of the adhesive, along at least a portion of the substrate(s) to which the adhesive has been applied; and c) allowing the adhesive to bond the substrates together.

A nozzle for dispensing adhesives has a body defining a fluid flow passageway between an inlet end and an outlet end. The nozzle has an outlet orifice in a sidewall of the body. The outlet orifice has an upper portion and a base portion separated by a shoulder.

Nozzle for applying adhesives

A method is provided for adhering a polyurethane-based sealant or adhesive to a substrate. The method comprises: i) applying an aqueous primer solution onto a substrate, the primer solution comprising water, an aminotitanate compound, and preferably an epoxysilane compound having at least one epoxy group and at least two alkoxy groups; ii) applying a polyurethane adhesive or sealant to the primer-treated substrate; and iii) forming a reaction product of the primer and the polyurethane. Also provided are a substrate having a layer of a polyurethane adhesive or sealant, and a stabilized aqueous primer solution containing an epoxysilane compound and an aminotitanate compound.

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Boonton, NJ, United States of America

Hong Yao