| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: invention relates to wood material in which a nitrogen-containing compound is distributed, where the said compound forms a cellular structure and is a product of condensation of formaldehyde in form of a cellular structure formed in amount (N) of at least 1 wt % in terms of nitrogen, relative the total weight of the wood material. The coefficient (FA/N) which is expressed as the ratio of extraction of formaldehyde (FA), determined using a method in a closed volume in accordance with EN 717, part 3, to the quantitative content of nitrogen (N) has maximum value of 3.5ù10-3, and the hold level of the nitrogen-containing compound is higher than 73%. The method of obtaining the wood material involves a) saturating wood material with an aqueous composition containing i) at east one nitrogen-containing compound which forms a cellular structure and ii) at least one substance which catalyses formation of the cellular structure, b) treating the saturated wood material at high temperature in order to remove water and to form a cellular structure from the nitrogen-containing compound which forms a cellular structure. Step b) of the process involves treatment of the saturated wood material at least once with superheated water vapour, followed by treatment at least once at temperature higher than 110C and with relative humidity of the gaseous medium surrounding the wood material of not more than 20%. The nitrogen-containing compound which forms the cellular structure is selected from: 1,3-bis(hydroxymethyl)-4,5-dihydroxyimidazolidin-2-one, 1,3-bis(hydroxymethyl)-4,5- dihydroxyimidazolidin-2-one, which is modified by an alkanol with 1-6 carbon atoms, a polyol with 2-6 carbon atoms or oligoalkyleneglycol, 1,3-bis(hydroxymethyl)urea, 1,3-bis(methoxymethyl)urea, 1- hydroxymethyl -3-methylurea, 1- hydroxymethyl-3-methyl-4,5- dihydroxyimidazolidin-2-one, 1- hydroxymethyl -4,5- dihydroxyimidazolidin-2-one, 1,3-bis(hydroxymethyl) imidazolidin-2-one, 1,3-bis(hydroxymethyl)-1,3-hexahydropyrimidin-2-one, 1,3-bis(methoxymethyl)-4,5- dihydroxyimidazolidin-2-one, tetra(hydroxymethyl)acetylenediurea, low-molecular melamine-formaldehyde resins and low-molecular melamine-formaldehyde resins which are modified with alkanol with 1-6 carbon atoms, polyol with 2-6 carbon atoms or oligoalkyleneglycol, mixtures of said compounds with each other, mixtures of said compound with not less than one compound V', which contains at least one free NH- group, and mixtures of said compounds with at least one compound V" which contains at least one hydroxyl group which is not part of the CH2OH group. ^ EFFECT: wood material has low release of formaldehyde. ^ 19 cl, 19 ex |
