CS261844B1 - Adhesive with reduced releasing of formaldehyde from large-surfaced lignocellulose materials and process for preparing thereof - Google Patents

Abstract

50 to 64 wt. urea-formaldehyde % of condensate, 35 to 49.92 wt. water and 0.08 to 5.6 wt. surfactants form glue, whose method of production is carried out by 1 to 10 wt. parts of surfactants with 10 to 100 wt. parts of water at 500 to 10,000 rpm / min. for 10 to 120 seconds and homogenizes with urea-formaldehyde resin at 1,000 to 10,000 rpm. for 10 to 60 seconds at a concentration of 0.08 up to 5.6 wt. surfactants related to urea-formaldehyde condensate mass.

Description

The present invention relates to a reduced formaldehyde release adhesive from large-scale lignocellulosic materials and to a process for its manufacture.

Hitherto known means for reducing formaldehyde ernisia from large-scale lignocellulosic materials made using urea-formaldehyde glue such as chipboard, shovel, sawdust, wood-fiber, thatch, plywood, blockboard will not sufficiently prevent the release of formaldehyde to the health of the environment. The release of formaldehyde from large-scale lignocellulosic materials, even several years old, is caused by the hydrolysis of the urea-formaldehyde adhesive under the effect of heat and moisture present in thatch. The release of formaldehyde causes great difficulties in the mass use of mainly particle board in furniture and construction.

Some means for reducing formaldehyde emission from large-scale lignocellulosic materials and the process of their production are now known which are added to the adhesive or applied to the finished thatch. Various nitrogen compounds such as urea (Ikeda M .; Japanese Patent 74, 18 926, Kawahara M .; Japanese Patent 73, 72 309), Melmine (Ikeda M .; Japanese Patent 74, 18 926, Szlezyngier M. et al; Polish Patent 74,060, 1975], guanidine and derivatives thereof (Niskina S .; Japanese Patent 73, 92,541), thiourea, dicyandiamine, caprolactamine, m-phenlenediamine (Starzynska K .; Polymers 18 [12] 639, 1973) aliphatic and aromatic azo compounds, ammonium salts of carbonic acid (Kellner et al .; AO CSSR 206 094) as well as oxygenated sulfur compounds, ammonium sulfide and polysulfides (Neumann R .; , staut AW: U.S. Patent 3,68638, Kubin T. et al .; AO CSSR 167 432, 1977) or urea and ammonium chloride evolution (Kawahara M .; Japanese Patent 73 72 309). Also by effecting ammonia gas on finished agglomerated thatch (e.g. Charles S .; Plywood and Panel 4, 1982, 8-9) or ammonia released from ammonium hydroxide it (Rofael E .; Miertzsch H., Menzel W .; Adhazion 26 [3], 1982, 18-231) reduces formaldehyde emission from large-scale lignocellulosic materials. A disadvantage of the described compositions is the lowering of the ratio of nitrogenous substances to formaldehyde, which results in a deterioration of the physical and mechanical properties of large-scale lignocellulosic materials, respectively. the achieved effect of reducing formaldehyde leakage is low. Some applications are disadvantageous for economic or operational reasons.

The disadvantages of the present state of the art are eliminated by the reduced formaldehyde release adhesive from large-scale lignocellulosic materials, which is based on the fact that it contains 50 wt. % to 64 wt. % urea-formaldehyde condensate, 35 wt. until

49.92% wt. % water and 0.08 wt. % to 5.6 wt. surfactants such as oxyethylene alkylphenols, oxyethylene fatty alcohols, ethylenediaminetetraacetic acid and nitrilotriacetic acid amides, fatty acid condensates with amino acids and polyamines, alkylarylsulfonates and sulfides. According to the process of the invention, 1 to 10 wt. parts of surfactants are mixed with 10 to 100 wt. parts of water at 500 to 10,000 rpm. for 10 to 120 seconds and homogenized with urea-formaldehyde resin at 1000 to 10,000 rpm. 10 to 60 seconds at a concentration of 0.08 wt. % to 5.6 wt. of surfactants based on the urea-formaldehyde condensate mass.

The advantages of the reduced formaldehyde release adhesive and the process according to the invention make it possible to produce large-area lignocellulosic materials of emission class Ei with better physico-mechanical properties than is currently achieved by reducing the urea to formaldehyde ratio and also to produce chipboard that is in emission class El special. at present, they do not produce in the world without a significant modification of the existing technology, which is simultaneously manifested as a higher effect of the invention. These benefits will also allow for increased use of agglomerated thatch in construction and will improve the hygiene of furniture products and interior hygiene. After venting, the removal of formaldehyde released by the compression of large-scale materials, the concentration of formaldehyde released into the atmosphere drops to 0.1 / g / ml of water.

Example 1

6.92 wt. % surfactants in the composition of 65% oxyethylene alkylphenols and 35% wt. of oxyethylene fatty alcohol is mixed with 96.8 parts of water at 1,000 rpm. for 20 seconds followed by a speed increase to 9,000 rpm. for 10 seconds. Mix the homogenized surfactant mixture with 692 wt. parts by weight of urea-formaldehyde resin at 9,000 rpm. within 20 seconds to prepare a means to reduce formaldehyde emission from large-area materials of 56.55% by weight. % urea-formaldehyde condensate, 42.58 wt. % water and 0.87 wt. surfactants.

Example 1 and d 2

1.13 wt. % of surfactants in a composition of 50 wt. nitrilotriacetic acid amide and 50 washes. wt. The fatty acid condensate with amino acids is mixed with 14.83 parts of water at 500 rpm. for 90 seconds followed by a speed increase to 9,000 rpm261844 β

choc / min. for 30 seconds. Mix the homogenized surfactant mixture with 323 parts urea-formaldehyde resin at 7000 rpm. over 30 seconds to prepare a means to reduce formaldehyde emission from large-area materials of 61.9 wt. % urea-formaldehyde condensate, 39.6 wt. % water and 0.3 wt. surfactants.

Example 3

31.5% by weight of the surfactant targets of 60% oxyethylene alkylphenol and 40% alkylarylsulfonate are mixed with 96.8 parts water at 1500 rpm. for 60 seconds followed by a speed increase to 10,000 rpm. for 40 seconds. Mix the homogenized surfactant mixture with 692 wt. parts by weight of urea-formaldehyde resin at 9,000 rpm. for 20 seconds to prepare a composition for reducing formaldehyde emission from large-scale lignocellulosic materials of 54.2 wt. % urea-formaldehyde condensate, 41.0 wt. % water and 5.0 wt. surfactants.

The reduced formaldehyde release adhesive from large-scale lignocellulosic materials and the method of its manufacture will be used in the woodworking industry in the manufacture, in particular of large-scale materials.

Claims (2)

CLAIMS 1. A reduced formaldehyde-release adhesive from large-scale lignocellulosic materials, characterized in that it comprises 50% by weight of the composition. up to 64% w / w. % urea-formaldehyde condensate, 35 wt. until 49.92% wt. % water and 0.08 wt. % to 5.6 wt. surfactants such as oxyethylene alkylphenols, oxyethylene fatty alcohols, ethylenediaminetetraacetic acid and nitrilotriacetic acid amides, fatty acid condensates with amino acids and polyamines, alkylarylsulfonates and sulfobetaines. INVENTION 2. A method according to claim 1, wherein 1 to 10 wt. parts of surfactants are mixed with 10 to 100 wt. parts of water at 500 to 10,000 rpm. for 10 to 120 seconds and homogenized with urea-formaldehyde resin at 1000 to 10,000 rpm. for 10 to 60 seconds at a concentration of 0.08 wt. % to 5.6 wt. of surfactants based on the mass of urea-formaldehyde condensate.