SU412211A1 - METHOD OF OBTAINING RESIN PHENOLFORMALDEHYDE RESINS - Google Patents

Description

one

The invention relates to the production of polymers — phenolic resins of phenol-formaldehyde resins used as a binder for the manufacture of filled plastics of various types (fibrine, getinax, textolite, etc.).

A known method for producing resole fepol-formaldehyde resins, encapsulates the polycodisation of phenol with formaldehyde in the presence of an alkaline catalyst at a temperature of about 100 ° C, the substance of the oligomer formed under vacuum of 500-650 mm Hg. Art. at a temperature of about 90 ° C for 3-4.5 hours and cooling the polymer obtained.

The disadvantages of this method are the cycle time, the complexity of the apiature design, the insufficiently high yield of the final product, due to the loss of phenol and formaldehyde with distilled water.

The purpose of the invention is to create a method for producing resole phenol-formaldehyde resins in a simple manner, reducing the time of the substance, simplifying the instrumentation, reducing the loss of phenol and formaldehyde, and increasing the heat resistance of the final product.

For this, after polycondensation, the obtained product is cooled to a temperature of about 80 ° C. J is introduced by the introduction of ethyl silicate.

5g (OSgN5) 4 in the amount of 1--5% of the total weight of the loaded components.

The described method of chemical drying is based on the decomposition of ethyl silicate with water 5 to obtain ethyl alcohol and silica sol, which are part of the final product.

The reaction proceeds according to the generalized equation:

0

Si (OC2H5) 4 + 2H20 4С2Н50Н + ISiOaln - colloidal solution.

Example 1. Laboratory synthesis of a phenol-formaldehyde-resin resol resin is carried out in a three-neck flask in a water bath, equipped with a stirrer, reflux condenser, and thermometer. 365 g of formalin (as a 37% aqueous solution) and 331 g of molten phenol are charged to the flask, 3.37 g of sodium hydroxide are transferred and injected. Polycondensation is carried out for 2 hours at 96-107 ° C. After condensation, the resin is cooled at .86 ° C and 23 g of ethyl silicate-32 are introduced and then the finished resin is cooled, which has the following characteristics: viscosity OZ-4-80-

5 120 sec; humidity 28–32%; brominating content not more than 9%.

The resulting product was tested in the manufacture and processing of fiber. To do this, the resin is mixed with cotton cellulose and with additives of talc, magnesia, lime and oleic acid, dried at 80-100 ° C and recycled into the product. The resulting fiber meets all the indicators GOST 5689-66.

Example 2. Experimental synthesis of resin on the plant equipment (apnarat with a capacity of 6.3 m with a jacket, a reflux condenser and a mixer, i have it; 60 rpm).

The composition of the resin is given in table. one.

Table 1

but cooled to 93 ° C in 10 minutes and to 80 ° C in 20 minutes, ethyl silicate is added and, with stirring, cooling is continued to 60 ° C, which takes approximately 1 hour and 10 minutes.

The end of the polycondensation is controlled by the viscosity of the semi-finished product, which according to VZ-4 should be in the range of 60 to 80 seconds.

The finished resin has the following indicators: viscosity according to VZ-4-80- | G20 sec: humidity (according to Dean and Stark) 30-: 35%; brominated content 4-7%.

Indicators of finished resins are given in table. 2

T a b and a 2

The phenol and formaldehyde loaded into the reactor is stirred for 5 minutes, then caustic soda is introduced. The mixture is heated with stirring in steps:

up to 80 ° C - 45 min

up to 87 ° C - 10 min,

up to 98 C - 15 min.

At the same time in the mixture proceeds the process of non-condensation.

In the reaction mass, maintained at 98-96 ° C for 50 minutes and the successor On the obtained resin prepared fiber VL-2. The results are shown in Table. 3

The remaining figures are within the limits of GOST 5689-66 for fiber optic tape VL-2.

Table 3