Abstract: A two part non-sag polyurethane construction sealant or adhesive is provided with the properties of low modulus, high elongation, good paint adhesion, and primerless adhesion to concrete surfaces. The sealant or adhesive is prepared using a polyol, and optionally an epoxy silane and/or a melamine compound, in the base component of the formulation; and a prepolymer reaction product including the residues of xylenol or xylenol and an additional polyol, and a polymeric isocyanate, an aromatic diisocyanate, or a polymeric isocyanate and an aromatic diisocyanate, and optionally an epoxy silane and/or a melamine compound, in the activator component of the formulation.

Abstract: A two part construction sealant or adhesive is provided with the properties of non-sag, low modulus, high elongation, and good paint adhesion. The sealant or adhesive is prepared using at least one of a secondary amine or an acrylate monomer, and a diol, triol and/or tetrol having a nominal weight average molecular weight of between 1,000 and 6,000 in the base component of the formulation, and aromatic diisocyanate monomer or polyisocyanate and an isocyanate terminated prepolymer of aromatic diisocyanate or polyisocyanate and polyol in the activator component, the components of Part A to Part B mixed at a weight ratio of 5:1 to 1.8:1.

Abstract: A two part construction sealant or adhesive is provided with the properties of non-sag, low modulus, high elongation, and good paint adhesion. The sealant or adhesive is prepared using at least one of a secondary amine or an acrylate monomer, and a diol, triol and/or tetrol having a nominal weight average molecular weight of between 1,000 and 6,000 in the base component of the formulation, and aromatic diisocyanate monomer or polyisocyanate and an isocyanate terminated prepolymer of aromatic diisocyanate or polyisocyanate and polyol in the activator component, the components of Part A to Part B mixed at a weight ratio of 5:1 to 1.8:1.

Abstract: A two part non-sag polyurethane construction sealant or adhesive is provided with the properties of low modulus, high elongation, good paint adhesion, and primerless adhesion to concrete surfaces. The sealant or adhesive is prepared using a polyol, and optionally an epoxy silane and/or a melamine compound, in the base component of the formulation; and a prepolymer reaction product including the residues of xylenol or xylenol and an additional polyol, and a polymeric isocyanate, an aromatic diisocyanate, or a polymeric isocyanate and an aromatic diisocyanate, and optionally an epoxy silane and/or a melamine compound, in the activator component of the formulation.

Abstract: A two-component urethane adhesive is disclosed which requires no primer or pretreatment of the substrate. The adhesive in cured form has superior paint adhesion and can withstand high temperature bake cycles without substantial losses in adhesion to the substrate. The adhesive differs from prior adhesives in that essentially all of the high molecular weight polyols in the prepolymer component are the reaction product grafting reactions of acrylonitrile onto polypropylene polyols.

Abstract: A two component primerless modified urethane adhesive having good high temperature stability can be utilized to bond substrates such as sheet molded composites together which can be subsequently powder coated. The utilization of the modified adhesive generally results in the formation of channels between the cured adhesive and the sheet molded composite surface so that upon cure of the applied powder coating, volatiles can escape from the sheet molded composite thus preventing blistering of the powder paint coating. The prepolymer component of the modified urethane contains a reacted hydroxyl intermediate and has a significant excess of free isocyanate. The curative component contains a polyol curing agent, an amine sag resistant agent, a trimerization catalyst, a low amount of urethane catalyst, and optionally a phosphorus-type adhesion promoter and/or molecular sieves.

Abstract: A two component primerless modified urethane adhesive having good adhesion can be utilized to bond various substrates together such as sheet molded compounds. The prepolymer component of the modified urethane contains a reacted hydroxyl intermediate and has a significant excess of free isocyanate. The curative component contains a polyol curing agent, an amine sag resistant agent, a phosphorus-type adhesion promoter, and optionally molecular sieves. The equivalent ratio of free NCO groups in the prepolymer component to OH groups plus any amine groups in the curative component is generally from about 0.90 to about 1.25.

Abstract: A two-component polyurethane composition has good shelf stability and the adhesive made by curing the same has good high temperature stability and no adhesion loss after high temperture bake. The base or prepolymer component containing a primary hydroxyl intermediate also has a sufficiently large excess of free isocyanate so that the ratio of free NCO groups in the prepolymer component to OH curative groups plus any amine groups in the curative component is generally from about 1.2 to about 2.0. The curative component contains a trimerization catalyst so that upon cure, isocyanurate units are produced. The system also contains molecular sieves, as well as phosphorous-type adhesion promoters.