Ceskoslovenska Akademie Ved

Jan Sebenda

Zbynek Bukac

Rudolf Puffr

Richard Suchy

Miloslav Loyda

Jaroslav Stehlicek

The invention relates to a method for the preparation of polyamides with enhanced electric conductivity (specific resistance below 10.sup.9 .OMEGA..cm) by the anionic polymerization of lactams with 7 to 13 atoms in the ring using the usual basic polymerization initiators and accelerating activators. The polymerization is carried out in the presence of 2-20 wt. parts of plasticizers, e.g. N,N-dialkoxy or N,N-dialkylacrylamides or methacrylamides or their polymers, polyethyleneoxide, polyamides or lactams of higher concentration of amide groups than has the principal lactam, and 1-50 wt. parts of a very finely ground graphite and/or conductive black per 100 wt. parts of anhydrous principal lactam or mixture of lactams.The polymerization is performed in a mold to give directly the required article or in continuous reactors to various profiles or to form granulates. The semiconductive polyamide, which is the product of this invention, is suitable, for instance, for use as machine parts operating under conditions where the formation of electrostatic charges should be eliminated (e.g. in mines, chemical plants, etc.) or for articles where the conductivity is usefully employed (e.g. low temperature heating elements).

Method for the preparation of polymers of lactams having an enhanced

The invention relates to a method for the cationic polymerization of lactams either substituted or unsubstituted on the lactam ring, which contain 6-16 carbon atoms, in the presence of 0.05 - 10 mol. % based on the lactam of an anhydrous salt of Cu, Zn, B, Al, Ti, Si, V, Sb, Bi, Cr, Mo, W, Mn, Fe, Co, Ni and an inorganic or organic anion such as phosphate, pyrophosphate, phosphite, sulfate, halide, carboxylate and sulfonate in the presence of 0.05 - 5 mol. % of a protic organic or inorganic acid such as pyrophosphoric, phosphorous, hydrohalic carboxylic and sulfonic. These additives can be added to lactam below 180.degree. C and the polymerization is carried out at 150.degree. - 320.degree. C for 0.1 - 200 hr. The above-specified salts, also their mixtures, can be used. The polymerization can be carried out with mixtures containing two or more lactams. The process can be carried out in a solvent and in the presence of various anhydrous inorganic fillers, such as glass fibers, ground minerals, powdered metals, metal oxides, phosphates, sulfates or sulfides or graphite. The process can also be effectively conducted in the presence of organic dyes, plasticizers and emulsifiers. If the polymerization is performed with the salts of cations which are spontaneously reduced by the lactam during polymerization, finely dispersed metals are formed and remain suspended in the polymer.

Method for the polymerization of lactams

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 the method for preparation of polymers containing N-acyllactam groups which are suitable as polymeric activators of anionic polymerization of lactams to obtain graft copolymers or block copolymers of the AB or ABA type, where A is the polyamide block. The polymers of the general formula I ##STR1## wherein R.sup.1 is a bifunctional aliphatic C.sub.2 - C.sub.15 hydrocarbon residue, n is an integer and P is a n-functional linear, branched or crosslinked polymeric residue, are prepared by the reaction of polymeric acyl halides of the general formula II ##STR2## where X = Cl or Br, with 1 - 5 mole of trisubstituted N-silyllactam, e.g. N-trimethylsilyllactams or N-phenyldimethylsilyllactams, per one equivalent of acyl halide group in an inert solvent at -15 to +100.degree. C (preferably 0.degree. to +30.degree. C). The polymeric acyl chlorides (the general formula II, X = Cl) are advantageously prepared from polymers containing carboxylic groups and 1 - 5 moles of PCl.sub.5 per one equivalent of carboxylic groups at -15.degree. C to +100.degree. C, preferably at 0.degree. C to +30.degree. C.

Method for preparation of polymers which contain N-acyllactam groups

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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Jan Sebenda