CS211798B1 - Method of preparation of the fusible pastes - Google Patents

Description

(54) Preparation of hot-melt adhesives

The invention relates to a process for the preparation of adhesives by copolymerization of two lactams of the general formula NH- (CH ₂ ) _x -CO, wherein x is 5, 7, 11.

Recently, more and more attention has been paid to the research and production of new polymer materials with the properties of so-called hot-melt adhesives, without which the modern clothing industry can no longer be imagined. These adhesive materials are applied only under the effect of heat, i.e., in the absence of solvents, hardeners and the like. Therefore, their use is very simple and economical. They are developed primarily for the textile industry, but are also used in the leather and furniture industries, packaging and the like.

The main requirements for the properties of hot-melt adhesives are: melting interval less than 150 ° C, preferably 100 to 130 ° C, melt index 20 to 50 g / 10 min at 190 ° C / 2.16 kg, good flexibility and wash resistance, and chemical screening. In particular, polyamides meet these requirements of possible polymeric materials. However, the melting range ranges for polyamides can only be achieved by simultaneous polymerization or polycondensation of more than two polyamide-forming monomers. Therefore, the presently manufactured hot melt adhesives and other adhesives are based on terpolymers of lactams or diacid salts with diamines. The most common components are 6-caprolactam, adipic acid salt with hexamethylenediamine and 12-dodecanlactam. Two-component copolymers of polyamide-forming monomers are not suitable because the melting interval of these copolymers cannot be reduced below 150 ° C.

These drawbacks are eliminated by a method for preparing hot melt adhesives copolymerization of two lactams of formula ΝΗ- (0Η ₂₎ -00 _χ, where x is 5, 7 11. Its principle consists in that the copolymerization is carried out in the presence of 0.1 to 30% by weight . natural or synthetic waxes, petroleum jelly, paraffins, low molecular weight polyolefins (H. h. 10 000) or mixtures thereof.

According to other features, the copolymerization can be carried out in the presence of hydrolytic catalysts at temperatures of 200 to 330 ° C or cationic catalysts, preferably in the presence of anhydrous phosphoric acid at the same temperature or anionic initiation systems at temperatures of 130 to 280 ° C. Finally, 6-caprolactam can be used as the starting lactams. and 12-dodecanlactam in a 1: 1 molar ratio.

The basic effect of the process according to the invention is in particular to accelerate the polymerization.

Among the λ-amino acid lactams, any pair of lactams of the general formula NH-CCHgl ^CO can be used, wherein x is 5, 7, 11, preferably particularly industrially produced pairs of lactams: 6-caprolactam and 12-dodecanlactam. The relative ratio of concentrations of both lactams affects the melting interval of the product. The lowest melting interval can be achieved at an equimolar ratio of both lactams. The preparation of hot-melt adhesives from the above-described mixture is carried out by a so-called hydrolytic mechanism, i.e. at temperatures of 200 to 320 ° C in the presence of water, omega-acids, or diamines and diacids salts as catalysts, but also in the presence of cationic or anionic catalysts. systems and also in the absence of catalysts. In the absence of catalysts, but also in the presence of so-called hydrolytic catalysts, the third component also has an activating effect on the polymerization; the acceleration of polymerization is particularly important when 12-dodecanlactam is used as one of the polyemide-forming components. In the presence of 5 wt. % of synthetic wax or natural wax, for example bees wax or lanolin in the starting equimolar mixture of these lactams, the copolymerization is complete after 100 hours.

The method according to the invention is further described in the examples and summarized in the tables.

Examples 1 to 22

0.48 moles of 6-caprolactam, 0.02 moles of 6-aminocaproic acid, 0.50 moles of 12-dodecanlactam were weighed into a glass ampoule and a certain amount of the third component was added to this comonomer mixture according to the data given in Table I. evacuated for 1 hour (1.6 kPa) and sealed under vacuum. The polymerization was carried out at 260 ° C and after the time indicated in the table an equilibrium copolymer was obtained. Its melting intervals and intrinsic viscosity of m-cresol solutions at 25 ° C are also shown in Table I.

Table I

Copolymerization of an equimolar mixture of 6-caprolactam and 12-dodecanlactam in the presence of a third component. Polymerization temperature 260 ° C, 2 mol% 6-aminocaproic acid catalyst

example the third component % wt. time after- interval lymeration thaw throw. Noc: 2 ° C 1 wax. mikrokryst. 5 96 128 to 132 1.34 2 those paraffin. 5 96 129 to 133 1.43 3 vaseline media. 2 96 135 to 139 1.16 4 lanolin 2 96 130 to 133 1.20 5 lanolin 5 96 126 to 130 0.84 6 lanolin '0 72 112 to 118 0.62 and beeswax sur. 5 96 126 to 129 0.48 8 beeswax refinery. 5 96 129 to 131 0.37 9 wax synth. 2 96 130 to 133 1.20 10 II 3 96 126 to 130 0.99 1 1 if 5 96 122 to 128 0.76 12 n 10 72 117 to 120 0.49 13 II 13 72 115 to 118 0.45

example the third component % wt. polymerization time throw. interval thaw Noc: 2 ° C 14 wax. synth. 24 72 90 to 95 0.36 15 Dec polyethylene (11 h. 5 000) 0.1 120 128 to 132 1.30 16 11 0.3 120 127 to 130 1,28 17 11 0.5 96 128 to 129 1,27 18 II 1 96 125 to 127 1,27 19 Dec 11 1.5 96 124 to 126 1.10 20 May II 15 Dec 72 120 to 123 1.05 21 polypropylene oil (M.h. 1,000) 0.5 120 129 to 131 1.31 22nd 5 96 120 to 122 1,28 internal viscosity of copolymer solutions in m-cresol (concentration 0.4 g of copolymers / 100 ml

m-cresol; 25 ° C) M.H. - molecular weight.

Examples 23 to 32

The monomers, in some cases also the initiator, were weighed into the glass ampoule and the modification component added to the mixture according to the data in Table II. The polymerization was carried out as described in Examples 1-22.

Table II

at- klad monomers mol% initiator mol% modifier wt. % polymerization time throw. interval thaw ° c 23 6KL, 48 8 KL, 50 AKK, 2 wax synth., 5 20 May 121 to 124 24 1, · ' II polypropylene oil (M. h. 1 000) 20 May 3 122 to 124 25 12LL, 50 8KL, 48 paraffin., techn., 10 72 122 to 128 26 polyethylene (M.h. 10 000) 0.5 96 127 to 130 27 Mar: 6KL, 50 12LL, 50 0 squalan, 5 120 128 to 132 28 8KL, 50 1, polyethylene (M.H., 0 000) ’, 5 96 125 to 128 29 II II wax. synth., 5 96 122 to 127 30 6KL, 48 II 6KL.H ₃ PO ₄ lanolin, 10 2 10 115 to 120 31 II II polypropylene oil (M.h. 1,000) 1 10 526 to 130 32 8KL, 48 AND. II polyethylene (M.h. 10,000), 1 10 125 to 127

6KL - 6-caprolactam, 3KL - 8-octanlactam, 12LL - 12-dodecanlactam, AKK - S-aminocaproic acid, 6-caprolactam phosphoric acid salt, squalan - 2, 4, 10, 15, 19, 23-hexamethyltetrakosen, M.H. - molecular weight

Examples 33 to 35

Anionic polymerization of 0.4975 mol of 6-caprolactam, 0.4975 mol of 12-dodecane lactam, 0.0025 mol of sodium salt of 6-caprolactam (initiator) and 0.0025 mol of 1-acetyl-β-caprolactam (activator) was carried out in adiabatic reactor at an initial temperature of 140 ° C. The modifying component was added to the molten monomers before delivery of the initiator system. Modifying components and their concentrations are shown in Table III.

Table III

Anionic adiabatic copolymerization of an equimolar mixture of 6-caprolactam and 12-dodecanlactam. % melting interval, ° C paraffin, techn., 2 lanolin, 5 polyethylene (M. h. 10 000), 5

133 to 136 126 to 130 122 to 125

Claims (5)

OF THE INVENTION Process for preparing hot-melt adhesives by copolymerization of two lactams. wherein x is 5, 7, 11, characterized in that the copolymerization is carried out in the presence of 0.1 to 30 wt. natural or synthetic waxes, oils, vaselines, paraffins, polyolefins having a molecular weight less than 10 000 or mixtures thereof. 2. Process for preparing hot-melt adhesives according to claim 1, characterized in that the copolymerization is carried out in the presence of hydrolytic catalysts at temperatures of 200 to 330 ° C. 3. Process for preparing hot-melt adhesives according to claim 1, characterized in that the copolymerization is carried out in the presence of cationic catalysts, preferably in the presence of anhydrous phosphoric acid at temperatures of 200 to 330 [deg.] C. 4. A process according to claim 1, wherein the copolymerization is carried out in the presence of anionic initiator systems at temperatures of from 130 to 280 [deg.] C. 5. Process for preparing hot-melt adhesives according to claim 1, characterized in that 6-caprolactam and 12-dodecanlactam are used in the molar ratio of 1: 1 as starting lactams.