US 5,668,234 AGranted

Reaction injection molding (RIM) of methyl (meth)acrylate and related monomers using group-4 catalysts

OwnerLarry Funderburk Rhodes, Brian Leslie Goodall +1inventors

InventorsLarry Funderburk Rhodes, Brian Leslie Goodall, Scott Collins

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Abstract

Acrylate monomers such as methyl methacrylate, or other suitable monomers such as lactams, lactones, or acrylamides, are polymerized by reaction injection molding (RIM) utilizing a combination of organo group-4 catalysts, e.g., a neutral organo catalyst and a cationic organo catalyst. Preferably a Lewis acid is utilized which reacts with the neutral organo catalyst and forms in situ the cationic organo catalyst. Significant exotherms are rapidly generated and result in short cure times and typically in high conversions of at least 95 percent by weight of the monomer. The catalysts of the present invention give good control of tacticity and thus high Tg polymers such as syndiotactic methyl methacrylate can be produced. The use of the combination organo group-4 catalysts are well suited for reaction injection molding of finished articles wherein the neutral catalyst is fed to a mixing device in at least one stream and the cationic organo catalysts or the Lewis acid is fed in at least one or more different streams.

Claims16

Dependent claims

A RIM process comprising;

the steps of
feeding at least one stream comprising (a) one or more neutral organo group-4 catalysts and one or more monomers to a mixing apparatus;
feeding at least one stream comprising (b) one or more activating cationic organo group-4 catalysts or one or more Lewis acids and one or more monomers to said mixing apparatus,
said at least one (a) and (b) streams, independently, having monomers comprising, a monomer of the formula:
##STR8## where R.sup.1 is hydrogen or an alkyl having from 1 to 4 carbon atoms and R.sup.2 is an alkyl or a cycloalkyl group having from 1 to 10 carbon atoms, or wherein R.sup.2 is R.sup.5 -silyl-R.sup.6 or R.sup.5 -siloxane-R.sup.7 where R.sup.5 is non-existent, or hydrogen, or an alkyl containing from 1 to 10 carbon atoms and where R.sup.6 or R.sup.7 is non-existent, hydrogen, or an alkyl having from about 1 to about 10 carbon atoms, wherein the number of silyl or siloxane repeat groups is from about 1 to about 1,000;
or a monomer of the formula ##STR9## wherein R.sup.3 and R.sup.4 independently, is hydrogen, or a hydrocarbyl, or a lactam monomer having from 3 to 9 carbon atoms in the ring, or a lactone monomer having from 3 to 9 carbon atoms in the ring, or wherein said lactam and said lactone monomers are a substituted lactam or lactone wherein said one or more substituents is an alkyl having from 1 to 5 carbon atoms,
or acrylonitrile or alkyl substituted derivatives thereof having from 1 to 4 carbon atoms,
or combinations of said monomers,
mixing said (a) and (b) streams,
transferring said mixed (a) and (b) streams into a mold, and
substantially polymerizing said monomers in said mold.

8 more elements

A polymer composition comprising the reaction product resulting from the combination of at least two substantially diluent free reactant streams to form a reactive mixture then conveying said reaction mixture into a mold where polymerization takes place, one reactant stream of which comprises one or more neutral organo group-4 catalyst(s) and one or more monomer(s), and another of which comprises one or more activating cationic organo group-4 catalyst(s) or an organic Lewis acid and one or more monomer(s), said one or more of each monomer(s) of each reactant stream, independently, having the formula:

##STR15## wherein R.sup.1 is hydrogen or an alkyl group having from 1 to 4 carbon atoms and R.sup.2 is an alkyl or a cycloalkyl group having from 1 to 10 carbon atoms, or wherein R.sup.2 is R.sup.5 -silyl-R.sup.6 or R.sup.5 -siloxane-R.sup.7 where R.sup.5 is non-existent, or an alkylene radical containing from 1 to 10 carbon atoms and where R.sup.6 or R.sup.7 is non-existent, hydrogen, or an alkyl group having from 1 to 10 carbon atoms, wherein the number of siloxane repeat groups is from about 1 to about 1000;
or a monomer having the formula:
##STR16## wherein R.sup.1 is as defined in the formula above and R.sup.3 and R.sup.4, independently, represent hydrogen, or a hydrocarbyl group;
or a lactam monomer having from 3 to 9 carbon atoms in the ring, or a lactone monomer having from 3 to 9 carbon atoms in the ring, or wherein said lactam and said lactone monomers are a substituted lactam or lactone, wherein said substituents are alkyl groups from 1 to 5 carbon atoms;
or an acrylonitrile monomer having the formula:
##STR17## wherein R is hydrogen or an alkyl group having from 1 to 4 carbon atoms;
or combinations of said monomers.

4 more elements

Dependencies are inferred from the claim text.