Ceskoslovenska Akademie Ved

Zbynek Bukac

Jan Sebenda

Richard Suchy

Miloslav Loyda

The invention relates to a method for manufacturing of anionic polycaprolactam with a low content of water extractables and high stability of the degree of polymerization during melting by a two-stage polymerization using known basic initiators and known activators of the following types: ##STR1## where R is ##STR2## R.sup.1 = R or C.sub.1-4 alkyl, cycloalkyl or allyl, R.sup.2 = C.sub.1-4 alkyl or H atom, n is an integer 3-11 and x is an integer &gt;3. The ratio of activator to initiator (e.g. sodium dihydromethoxyethoxyaluminate) ranges between 2.6 and 4.2, advantageously 2.8-3.5 The first polymerization stage proceeds at 150.degree.-200.degree. C. for .ltoreq.10 min, the polymer is then shaped and postpolymerized at 150.degree.-200.degree. C. for .ltoreq.90 min to achieve a monomer content near to the equilibrium content corresponding to the 2nd stage temperature.

Anionic polymerization of caprolactam at a temperature below the melting

The invention relates to hot-melt adhesives based on anionic copolymers of lactams, where one of the starting lactams is 8.octanolactam in the amount of 10-90 mol.% and the other at least 2 lactams containing 6 or more 6 atoms in the ring are in the amount 90-10 mol.%. These further lactams are preferably 6-hexanolactam and 12-dodecanolactam. The melt adhesives may contain further additives, as dyes, fillers, molecular weight regulators, etc. The anionic copolymerization used for their manufacturing is the simple and rapid technique which requires lower temperatures and can be easily performed continuously. The said polyamide melt adhesives are applicable e.g. in clothing and footwear industry and other textile and leather working.

Hot-melt adhesives based on anionic terpolymers of lactams

Preparation of polyamides by anionic polymerization or copolymerization of cyclic lactams which comprises conducting the polymerization in the presence of a six membered cyclic co-catalyst containing three ##STR1## groups and represented by the formula: ##STR2## wherein R.sub.1 and R.sub.2 are each selected from the group consisting of aryl groups, or containing two ##STR3## groups and represented by the formula: ##STR4## wherein R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each selected from the group consisting of alkyl (C 1-18) and aryl groups and combinations thereof, and X.sub.1, X.sub.2 and X.sub.3 are either sulphur or oxygen, except that at least two members of the group X.sub.1, X.sub.2 and X.sub.3 must be oxygen. Preferably, the aryl contains from 1 to 3 benzene rings, or can be an alkoxyaryl or dialkylaminoaryl. The alkyl can be an arylated alkyl.

Preparation of polyamides by anionic polymerization with substituted

The invention relates to a method for manufacturing anionic polyamies, copolyamides and lactam oligomers with a chemically bonded dye. The dyes are of the general formula

Method for producing anionic polyamides with chemically bonded dye

The invention relates to a method for producing cyclic trimers of organic isocyanates from isocyanates employing as catalyst sodium dihydro-bis-/alkoxyethoxy/aluminates of the general formula

Method for producing cyclic trimers of organic isocyanates

A method of preparing polyamides by anionic polymerization of cyclic lactams which comprises polymerizing at least one such lactam in the presence of at least one co-catalyst selected from the group consisting of N-substituted 1,3-oxazines, 1,3-thiazines, trioxopipendines and thioxopiperidines.

Preparing polyamides by anionic polymerization of lactams

A method of preparing polyamides by anionic polymerization of cyclic lactams which comprises polymerizing at least one such lactam in the presence of at least one co-catalyst selected from the group consisting of N-substituted 1,3-oxazines, 1,3-thiazines, trioxopiperidines and thiodioxopiperidines.

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Prague, Czechia

Zbynek Bukac