SU852885A1 - Method of preparing water-soluble phenolformaldehyde resins - Google Patents

Description

alkali, which under the conditions of e-operation, destroys the mineral fiber and the binder itself. In addition, the use of sodium hydroxide as a catalyst leads to the predominant formation of para-substituted phenol-alcohols, differing from ortho-substituted phenol-alcohols (obtained using barium hydroxide) with lower and less stable 1P | strength characteristics after curing.

Known phenol-0 | rmaldelidny resin, modified ketoiami, possessing improved toxicity indicators. Its condensation of 1 mol of phenol with 2-6 mol of formaldehyde in the presence of 0.35 mol of caustic and sodium is obtained by condensation. After 4 h from the beginning. Condensation is introduced 2-8 mol of keto and continue to condense for another 10 h. The finished product contains small amounts of non-realizing phenol (0.002%) and formaldehyde (0.1%), has a high 1 durability and solidified form, but not soluble in water and therefore cannot be used as a binder for mineral wool products 2.

The closest to the invention to the technical essence and DO | Stigaemo effect is a method of obtaining a water-soluble phenol resin-aldehyde resin, which includes a coolant phenol. Formaldehyde at 50-60 ° C for 8-10 hours at a weight ratio of phenol to formaldehyde equal to 100: 68-74 in the presence of a catalyst - barium hydroxide 3. The phenol alcohols obtained in this way have a short useful life (approximately 20 days). Therefore, it is impossible to provide consumer plants located for a considerable period with such phenol alcohols. or x on specialized enterprise-phenol synthesis. In addition, the synthesis of the above phenol alcohols requires a relatively large amount of deficient synthetic phenol (about 660 kg per ton of 100% phenol alcohols).

The purpose of the invention is to increase the storage stability of phenolformaldehyde resins and to reduce the consumption of phenol.

The goal is achieved by the fact that in the process of obtaining water-soluble phenol-formaldehyde resins, including the co-condensation of phenol with formol aldehyde 50–60 ° C in the presence of hydrooxide and barium, condensation is carried out at a phenol-formaldehyde ratio of 100: 72 -80 and additionally 5.5-8 hours after the start of condensation, anetone in the amount of 15-65 wt. hours per 100 weight. including phenol.

If acetone is introduced at the beginning of the reaction, the speed will decrease significantly and the condensation time will increase, but the useful life of the binder will not increase. In addition, the resulting product has an increased amount of free monomers and reduced strength properties in cured form. With the introduction of acetone into the finished product, the useful life of phenoalcohols increases from 20 to 40 days. However, the resistance of the cured resin to moisture decreases sharply. Only the introduction of acetone into the reaction mixture at a certain moment in the indicated amount of 5 ensures the preparation of a resin with increased stability and good strength indicators.

Example 1. In a round-bottomed flask equipped with a mechanical stirrer, cooler and thermometer, 127.9 g of synthetic phenol, 248.7 g of 37% formalin solution and 15.1 g of hydroxide octapydrate bar.i. The mixture was stirred for 8 hours at a temperature of 55- .60 ° C, 5 after which 40.8 g of acetone was added and condensation was continued for another 2 hours. The main technical characteristics of the obtained product are given in the table.

Example 2. In a round-shaped flask equipped with a mechanical stirrer, a cooler and a thermometer, 127.9 g of synthetic phenol, 264.8 g of a 37% formalin solution and 15.1 g of octane hydroxide barium hydroxide are charged. The mixture was stirred for 6 hours at a temperature of 55-60 ° C, after which 40.8 g of acetone was added and the condensation was continued for another 2 hours. The main technical characteristics of the obtained product are shown in the table. 0 EXAMPLE 3. A round-bottom flask equipped with a mechanical stirrer, a cooler, and a thermometer was charged with 127.9 g of synthetic phenol, 275.8 g of 37% foil oil, and 15.1 g of barium hydroxide 45 octahydrate. . The mixture was stirred for 5.5 hours at a temperature of 55-60 ° C, after which 83.1 g of acetone was added and condensation was continued for another 1.5 hours. The main technical characteristics of the obtained product 50 are listed in the table.

The stability of the resin makes it diluted with water. The resin is considered suitable for the production of mineral wool products when diluted with water at a 55 ratio of at least 1: 3 with no sediment.

Dilution with Water is determined by periodically adding water to the resin cylinder, followed by shaking. 60 DOSE is added to the resin until a mutation appears. The maximum water dilution of the resin, expressed as a volumetric ratio of resin and water, is considered to be a ratio at which the solution starts to grow turbid, but 65 with mixing the liquid disappears.

Claims (1)

Claim 15 A method for producing water-soluble phenol-formaldehyde resins, including condensation of phenol with formaldehyde at 50-60 ° C in the presence of barium hydroxide, characterized in that, in order to increase storage stability and reduce phenol consumption, condensation is carried out at a weight ratio of phenol to formaldehyde of 100: 72–80, and additionally, after the start of condensation, after 25.5.5–8 hours, acetone was added to the reaction mixture in an amount of 15–65 weight. hours per 100 weight. including phenol.