PL111972B1 - Catalyst for polycondensation of urea-formaldehyde resins - Google Patents

Description

and III shown in Table 10, were used after processing for the production of 16 mm particle boards. with dimensions of 40x56 cm. Each set was used to spray 10 kg of wood chips. Three plates were formed by hand for each set. The plates were pressed at 11 sec/mm. Press temperature 200°C and pressure 35 kg/cm 2 . 11, the average results of the three values are given. It is obvious that all 3 kits are equal and even better than the control kit 4, i.e. without the catalyst according to the invention. Table 10 20 25 30 1 1 Urea formaldehyde glue 65% ammonium 15% Hexamethylenetetraamine emulsion 20% Solution 1 Solution 2 1 Solution 3 Water 1 Sets used I 2 1177 0270 0077 0203 0208 — — 0053 | II 3 1177 0270 0077 0203 — 0208 — 0053 III 4 17 ¦— .— 0208 0053 | IV 5 | 1385 0270 0077 0203 — — — 0053 1 Table 11 Symbols Set I Set II III 1 IV Density kg/m3 712 668 701 731 Contractual bending strength kp/cm2 184 144 204 195 tensile kg/cm2 5.2 .4.9 6.8 4.4 Swelling after 2 hours in % 6.0 8.0 5.0 13.1 Swelling after 24 hours w% 21.4 24.3 17.0 23.2 Similar results can be obtained by replacing sodium or potassium chloride with lithium chloride or sodium, potassium or lithium fluorides, bromides or iodides in the above examples. the following three solutions: formaldehyde (calculated as 100%) urea sodium chloride water 106 160 27 707 this was prepared 11 16 260 713 183 292 98 427 1000 1000 1000 while solution 2 has an organic/inorganic ratio of 0.1/1.0 Both samples contain 29% solids Solution 3 is more concentrated at 57% solids with an "organic to inorganic" ratio is 4.8/1.0 These solutions have been used in kits 50 55 60 65 Claims 1. A catalyst for the polycondensation of urea-formaldehyde resins used to bind water-permeable cellulose molecules which, when used in combination with the known with a catalyst increases the rate or degree of polycondensation of the resin, while allowing the use of smaller amounts of solid resins without loss of binding capacity, characterized in that it contains a mixture of organic and inorganic components in the amount of 30-150 parts by weight per 100 parts by weight of water, and the organic components contain formaldehyde and urea or a non-resinous condensation product of formaldehyde and urea, and the inorganic component contains a water-soluble alkali metal halide, the weight ratio of organic to inorganic components being 0.1-10.0:1 .0 parts by weight. 2. A catalyst according to claim 1, characterized in that it contains formaldehyde and urea as organic ingredients, and sodium chloride as inorganic ingredient. LDD Z-d 2 W Pab., Z. 893/1400/81, n.

Claims (2)

1. Claims 1. Catalyst for the polycondensation of urea-formaldehyde resins used to bind water-permeable cellulose molecules, which, when used in conjunction with a known catalyst, increases the rate or degree of polycondensation of the resin while allowing the use of smaller amounts of solid resins without the occurrence of with a loss of binding capacity, characterized in that it contains a mixture of organic and inorganic components in the amount of 30-150 parts by weight per 100 parts by weight of water, the organic components being formaldehyde and urea or a non-resinous condensation product of formaldehyde and urea, and the component the inorganic contains a water soluble alkali metal halide, the weight ratio of organic to inorganic being 0.1 to 10.0:1.0 parts by weight. 2. A catalyst according to claim The product according to claim 1, characterized in that it contains formaldehyde and urea as organic components and sodium chloride as inorganic component. LDD Z-d 2 W Pab., Z. 893/1400/81, n. 95+20 copies Price PLN 45 PL PL PL