Dow Global Technolgoies LLC

Ddp Specialty Electronic Materials Us, LLC

Ddp Specialty Electronic Material Us, LLC

The Dow Chemical Company

Daniel Schneider

Andreas Lutz

Irene Maeder

Gary Lee Jialanella

Stefan Schmatloch

David H Bank

Bindu Krishnan

Marcel Aschwanden

Glenn G Eagle

Sergio Grunder

Paul Rohrer

Eric E Cole

Jeannine Flueckiger

Ilona Caderas

Felix Koch

Bharati Balijepalli

Christof Braendli

Tyler Auvil

Michael Ras

Detlef Symietz

Benjamin Alexander Haag

Adam K Schmitt

Nina Hillesheim

Filippo Ardizzone

Gary L Jialanflla

An epoxy-based crash durable adhesive composition including: (I) a liquid resin system comprising: (a) at least one epoxy resin; and (b) at least one toughener; wherein the viscosity of the above liquid resin system is less than about 800 Pa s at a temperature of 15&#xb0; C.; and wherein the viscosity of the above liquid resin system is greater than about 5 Pa-s at a temperature of 60&#xb0; C.; (II) a solid material comprising: (c) at least one hydrophobic fumed silica, wherein the fumed silica is present in the adhesive composition at a concentration of greater than 5 weight percent; and (III) a curative material comprising: (d) at least one latent heat-activated curing agent; wherein the rheology of the epoxy-based crash durable adhesive composition is such that the adhesive composition is pumpable at a temperature of 15&#xb0; C. or greater; and wherein the epoxy-based crash durable adhesive composition exhibits an increase in wash-off resistance; a process for making the above adhesive composition; and a process for bonding metal substrates together with the above adhesive composition.

Adhesive composition

The invention is an epoxy resin system useful as an adhesive for high temperature applications. The system is a combination of a diglycidyl ether a bisphenol epoxy resin(s), at amounts of 30-70% by weight, with 1-10% by weight of an epoxy novolac resin 10-30% by weight of a polyurethane toughener which preferably has the terminal isocyanate functional group blocked, 1-8% by weight of a hardener, 0.1-% by weight of a cure accelerator, preferably a latent urea cure accelerator, provides the desired balance of mechanical strength and elastic modulus. The epoxy novolac resin is characterized by at least one of the following features: (i) having a viscosity at 25 degrees C. of less than 3000 mPa-s according to ASTM D-445, (ii) an average number of epoxide groups per molecule of more than 2 but less than 3.7, and (iii) a molecular weight of less than 750 g/mol.

High temperature epoxy adhesive formulations

A resin composition is comprised of an epoxy resin comprised of a solid epoxy resin and a liquid polyurethane toughener that is dissolved in the epoxy resin and, upon curing of the liquid epoxy resin, the liquid polyurethane toughener phase separates into particles having a particle size of 50 nm to 2 micrometers, an epoxy hardener; and an epoxy soluble latent catalyst. The resin composition provides a more homogeneous infusion of the resin into a fibrous material for forming a prepreg and ultimately an epoxy fiber reinforced composition with improved toughness without sacrificing speed of impregnation or uniformity of the epoxy matrix within the composite.

Epoxy-fiber reinforced composites, method to form the composites and epoxy resin composition used therefor

Adhesive bonds are applied by mixing two adhesives with different properties and dispensing them to form bondlines between substrate pairs. The adhesives are then thermally cured and cooled. Varying the mix ratio permits one to vary the properties of the adhesive mixture so formed for use in bonding many different substrate pairs. The process allows potentially infinite variations of adhesive properties between those of the respective starting adhesives, simply by varying the mix ratio. The invention is especially adapted for use in manufacturing settings in which adhesives are to be applied in multiple places, but differing adhesive properties are needed among the various bonding areas.

Method for bonding using one-component epoxy adhesive mixtures

Epoxy adhesives include a latent curing agent, a reactive toughener having capped isocyanate groups, and certain urea compounds. The toughener is made by chain extending and capping a mixture of isocyanate-terminated prepolymers. The prepolymers include an isocyanate-terminated polyether and an isocyanate-terminated diene polymer. The adhesives have excellent wash-off resistance and excellent ability to adhere to oily substrates.

One-component toughened epoxy adhesives with improved adhesion to oily surfaces and high wash-off resistance

A new polyurethane (PU) adhesive composition with encapsulated hardeners having unique properties in automotive related applications.

Dual cure 1K PU adhesive formulations using matrix encapsulated polyamines

A one-component structural adhesive comprising an isocyanate-terminated prepolymer having polymerized residues of: (a) 40 to 95 wt % of a polytetramethylene ether glycol; and (b) 5 to 60 wt % of an aliphatic diisocyanate.

One-component structural adhesive containing isocyanate-terminated prepolymer

A new polyurethane (PU) adhesive composition having unique properties in automotive related applications such as composite bonding.

Structural PU adhesive for composite bonding

The present invention provides low polyphenols (such as bisphenol A) tougheners for epoxy adhesives. The tougheners, and adhesives comprising the tougheners exhibit enhanced viscosity stability, e.g., compared to tougheners prepared from higher amounts of bisphenol A (and epoxy adhesives comprising them).

Epoxy resin with enhanced viscosity stability and use thereof

Structural adhesives are prepared from an elastomeric toughener that contains urethane and/or urea groups, and have some terminal isocyanate groups that are capped with a phenol and other terminal isocyanate groups that are capped with a hydroxy-functional acrylate or a hydroxy-functional methacrylate. In certain embodiments, the presence of both types of capping on the toughener leads to higher impact peel strengths and a greater level of cohesive failure, than when the toughener is capped with a phenol an hydroxy-functional acrylate or hydroxy-functional methacrylate alone.

One-part structural epoxy resin adhesives containing elastomeric tougheners capped with phenols and hydroxy-terminated acrylates or hydroxy-terminated methacrylates

Structural adhesives are prepared from a chain extended elastomeric toughener that contains urethane and/or urea groups, and have terminal isocyanate groups that are capped with a phenol, a polyphenol or an aminophenol compound. The adhesives have very good storage stability and cure to form cured adhesives that have good lap shear and impact peel strengths.

Structural epoxy resin adhesives containing chain-extended elastomeric tougheners capped with phenol, polyphenol or aminophenol compounds

Structural adhesives are prepared from an elastomeric toughener that contains urethane and/or urea groups, and have terminal isocyanate groups that are capped with ketoxime compound. The adhesives have very good storage stability and cure to form cured adhesives that have good lap shear and impact peel strengths, even at &#x2212;40&#xb0; C.

Structural epoxy resin adhesives containing elastomeric tougheners capped with ketoximes

The invention is an epoxy resin based adhesive composition comprising an epoxy resin and a compound comprising an elastomeric prepolymer residue selected from the group of a polyurethane, a polyurea and a polyurea polyurethane having isocyanate end groups, the isocyanate end groups of said prepolymer residue being capped by a capping compound selected from the group consisting of a primary aliphatic, cycloaliphatic, heteroaromatic and araliphatic amine, a secondary aliphatic, cycloaliphatic, aromatic, heteroaromatic and araliphatic amine, a thiol and an alkyl amide, said capping compound being bound to the end of the polymer chain of the elastomeric prepolymer in a manner such that the end to which it is bonded no longer has a reactive group. In addition to the capping compound defined above above, a capping compound selected from the group consisting of a phenol and a polyphenol can be used for capping the isocyanate end groups of the prepolymer residue.

Toughened epoxy adhesive composition

Epoxy adhesive compositions contain an epoxy resin, rubber modification, a toughener and a curing agent. The tougher has capped epoxide-reactive groups, and at least one polytetrahydrofuran block having a mass of 2200-4500 daltons. The selection of toughener in a rubber-modified epoxy-based structural adhesive provides for very good low temperature performance.

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Waedenswil, Switzerland

Daniel Schneider