Urethane polymers and sealant compositions containing the same
AssigneeTremco Incorporated
InventorsLarry R. Barron, Herbert M. Turk
Life of this patent
Estimating the term…
Abstract
Novel, curable polyurethane polymers in which a proportion of the NCO terminations are reacted with certain amino silanes, or with the residual on reaction of a mercaptosilane with a monoepoxide, or with the residual on reaction of an epoxysilane with a secondary amine. Sealant compositions formed with the novel polymers are stable in storage, moisture curable and adhere well to various substrates, obviating the need for a primer.
Claims21
A curable organic polymeric material having an average molecular weight within the range of about 1000 to about 15,000 and having at least 2 functional groups per average molecular weight not more than 99% of which are NCO, and the balance being selected from the group consisting of ##STR6## where R is an alkylene of 2- 18 carbon atoms
- R.sub.1 is a lower alkyl of 1-6 carbon atoms
- R.sub.2 is --H or --CH.sub.3
- R.sub.3 is --C.tbd.N or ##STR7## and, R.sub.4 is an alkyl of 1-18 carbon atoms, an epoxyalkyl of 3-8 carbon atoms, an alkoxyalkyl of 2-12 carbon atoms, or --C.tbd.N, and ##STR8## where R.sub.5 is the residual on reaction of a mercaptosilane with a monoepoxide or an epoxysilane with a secondary amine.
A curable organic polymeric material formed by reacting a polyol having a hydroxyl functionality in excess of 2 and an average molecular weight within the range of about 1000 to 15,000 with a stoichiometric excess of a polyisocyanate to provide an NCO terminated polyurethane prepolymer, and reacting at least 1% of said NCO terminations with a material selected from the group consisting of ##STR9## where R is an alkylene of 2- 18 atoms
- R.sub.1 is a lower alkyl of 1-6 carbon atoms
- R.sub.2 is --H or --CH.sub.3
- R.sub.3 is --C.tbd.N or ##STR10## and R.sub.4 is an alkyl of 1-18 carbon atoms, an epoxyalkyl of 3-8 carbon atoms, an alkoxyalkyl of 2-12 carbon atoms, or --C.tbd.N,
- b. the reaction product of a mercaptosilane with a monoepoxide, and
- c. the reaction product of an epoxysilane with a secondary amine.
A method of forming a sealant composition having improved adhesion comprising the steps of reacting a polyol having a hydroxyl functionality in excess of 2 and an average molecular weight within the range of about 1000 to 15,000 with a stoichiometric excess of a polyisocyanate to provide an NCO terminated polyurethane prepolymer, reacting at least 1% of said NCO terminations with a material selected from the group consisting of ##STR11## where R is an alkylene of 2-18 carbon atoms
- R.sub.1 is a lower alkyl of 1-6 carbon atoms
- R.sub.2 is --H or --CH.sub.3
- R.sub.3 is --C.tbd.N or ##STR12## and R.sub.4 is an alkyl of 1- 18 carbon atoms, an epoxyalkyl of 3-8 carbon atoms, an alkoxyalkyl or 2-12 carbon atoms, or --C.tbd.N,
- b. the reaction product of a mercaptosilane with a monoepoxide, and
- c. the reaction product of an epoxysilane with a secondary amine, thereby forming a silane modified polyurethane polymer, and with fillers and pigments to form a sealant composition.
Dependencies are inferred from the claim text.