Method of preparing a low molecular weight paper size polymer by continuous polymerization in the absence of initiator

A process for the manufacture of a paper size by continuous polymerization of:

• a. from 30 to 85 percent by weight of olefins of 2 to 12 carbon atoms having a terminal double bond selected from the group consisting of ethylene, propylene, butene-1 and 4-methylpentene-1, olefins containing aromatic group and having up to 12 carbon atoms selected from the group consisting of styrene and vinyl toluene, vinyl ethers selected from the group consisting of vinyl methyl ether, vinyl ethyl ether, vinyl n-propyl ether, vinyl isopropyl ether, vinyl n-butyl ether, vinyl sec.-butyl ether, vinyl tert.-butyl ether and vinyl dodecyl ether and mixtures thereof,
• b. from 15 to 70 percent by weight of one or more basic acrylic and/or methacrylic compounds of the general formula ##STR12## where R.sup.1 is H or CH.sub.3, R is alkyl of 1 to 4 carbon atoms, --CH.sub.2 OH or --CH.sub.2 --CH.sub.2 --OH, X is --O--CH.sub.2 --CH.sub.2 --, --O--CH.sub.2 --CH.sub.2 --CH.sub.2 --, ##STR13## or --NH--(CH.sub.2).sub.n --CH.sub.2 -- and n is from 1 to 3, at from 130.degree. to 320.degree. C, in the absence of polymerization initiators said process taking place at a pressure of greater than 1 bar and with a residence time of from 3 to 60 minutes.