摘要:
The invention relates to a process for bonding surfaces with isocyanate-containing prepolymers having an isocyanate group content of less than 1.8% by weight, based on the prepolymer, and an average molecular weight MW.sub.n of at least 4,500 in which (a) the prepolymers are prepared by the reaction of (i) polyester diols prepared from dodecanedioic acid and even-numbered alkane diols containing at least 6 carbon atoms and (ii) diisocyanates; (b) the prepolymer is applied as a hotmelt adhesive at a temperature of 80 to 160.degree. C. by spin-spraying onto at least one surface to be bonded; and (c) the treated surface is brought into intimate contact with a second surface to be bonded.
摘要:
This invention relates to crystalline, isocyanate group-containign hot melt adhesives based onfrom 70-95% by weight of a prepolymer A based on polyester diols having a molecular weight of from 1500 to 10,000 and melting points of from 50.degree. to 90.degree. C. and diisocyanates in a ratio of isocyanate groups of the diisocyanate to the hydroxyl groups of the polyester diol of from 3:1 to 1.2:1 andfrom 5-30% by weight of a component B having a molecular weight of from 1000 to 10,000 based on polyesters having melting points of from 60.degree. to 150.degree. C., in which component B contains at most 0.5 Zerewitinow active groups per molecule.
摘要:
The present invention relates to solvent-free two-component polyurethane adhesive systems with high initial strengths and low levels of migration derived from a select reactants comprising a hydroxyl polyester and an isocyanate containing prepolymer.
摘要:
Disclosed herein is a transparent adhesive containing isocyanate groups based on at least one polyol and at least one polyisocyanate, characterized in that the adhesive contains urea groups.
摘要:
The present invention is directed to a polyurethane system containing isocyanate groups prepared by reactingA) 70 to 98 parts by weight of at least one polyester diol having a melting point of 30.degree. C. to 60.degree. C. and a molecular weight of 800 to 8,000,B) 2 to 30 parts by weight of at least one polyester diol having a melting point of 65.degree. C. to 150.degree. C. and a molecular weight of 600 to 8,000, andC) no more than 1 mole of a diol having a molecular weight of less than 600 per moles of A) plus B), with,D) at least one organic polyisocyanate, the ratio of isocyanate groups to hydroxyl groups is between 3:1 and 1.2:1.
摘要:
The present invention relates to aqueous polyurethane dispersions based onA) a relatively high molecular weight polyhydroxyl component containing carboxylic acid groups,B) optionally another relatively high molecular weight polyhydroxyl component which is substantially free of carboxylic acid groups,C) optionally low molecular weight polyhydroxyl compounds as chain lengthening agents,D) organic polyisocyanates andE) a neutralizing agent capable of converting the carboxylic acid groups into carboxylate groups,the dispersions are characterized in that the carboxyl group-containing relatively high molecular weight polyhydroxyl component A) is the esterification product of a polyether polyol a1) in the molecular weight range of from 400 to 5000, with a polycarboxylic acid a2); the dispersions are useful as laminating adhesives.
摘要:
The present invention relates to inner coatings of metal food containers and packaging and to a process for their production. The coatings are appied to the inside of at least a portion of the surface area of containers that are in direct contact with foods or other consumable products and subsequently cured. The coatings include a) at least one polyisocyanate containing an average of at least two NCO groups per molecule, at least 95% of the NCO groups being blocked with a blocking agent, and b) at least one polyhydroxyl compound containing an average of at least two hydroxyl groups per molecule that react with NCO groups.
摘要:
The present invention relates to heat-curable reaction systems prepared by mixing (a) solid polyisocyanates (optionally deactivated) having melting points above 80.degree. C., (b) OH- and/or NH.sub.2 -terminated polyoxyalkylene polyethers that have molecular weights of 400 to 10,000 and are liquid at room temperature, (c) solid OH- and/or NH.sub.2 -terminated polyesters that have molecular weights of 400 to 20,000 and are solid at room temperature, and which are thoroughly distributed throughout the mixture but are not homogeneously miscible with the polyether, (d) optional low molecular weight chain-extending agents that contain OH and/or NH.sub.2 groups and have a molecular weight of 62 to 399, and (e) optional catalysts and other auxiliaries. The invention further relates to a method for preparing elastomers, coating compounds, sealing compounds, or adhesives by heat-curing the heat-curable systems.
摘要:
This invention relates to modified polyetheramide hotmelt adhesives showing reduced melt viscosity and, optionally, better adhesive properties and to their use as ingredients for hotmelt adhesives.
摘要:
The present invention is directed to a polyurethane reactive adhesive compound comprising:A) one or more polyisocyanates having an inactivated particle surface,B) at least one isocyanate reactive compound having a molecular weight MG.sub.w greater than 400, andC) finely dispersed polymer particles, wherein the polymer is solid at temperatures below 70.degree. C. and has a molecular weight MG.sub.w of at least 3000.