SU876662A1 - Method of producing oligophenols - Google Patents

Description

(54) METHOD OF OBTAINING .OLIGOPHENOLS

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This invention relates to a process for the preparation of oligophenols and can be used for chemical preparation for the production of press materials of the type of areoplasts and epoxy resins.

A known method for the preparation of oligophenols by condensation of 2,5-dichloro-p-xylylene dichloride with -phenol. Q next vacuum distillation of excess free phenol tlJ

The disadvantage of this method is the high content of residual free phenol in the final product (about 3 wt.%) ..

The closest to the proposed technical essence is the method of producing oligophenols by polycondensation of chlorine-substituted p-xylylenedichloride 1 dA in polyphenols in mass, followed by removal of unreacted phenol from the resulting oligomer by vacuum distillation at a residual pressure of 5-10 mm. Hg and 170-190 C 23. ,

The disadvantage of the method lies in the significant content of the remaining free phenol in the product, which increases the content of volatile impurities in the oligomer, which is adversely affected

on the conditions of processing of phenolic and epoxy resins in the product, ear. It exploits the performance properties of finished products. :.

The purpose of the invention is to reduce the content of volatile impurities in the oligomer and increase the physicomechanical hardened epoxy resins.

The goal is achieved by the fact that in a known method of producing oligophenols by polycondensation of chlorine substituted in the nucleus of p-xylylene chloride by mass phenylphenol, followed by removal of unreacted phenol from the resulting oligomer by vacuum distillation at a residual Pressure mm. Hg Art. and 170-190 ° C. Before distillation of the phenol, 5-8 wt.% (based on the purified oligomer) of benzylphenol are introduced into the polycondensate.

Maximum free phenol is possible due to the large difference in the boiling points of phenol and benzylphenol (70 and 150 ° C, respectively, at 4 mm Hg), as well as the ability of benzylphenol to decrease the viscosity of the polycondensate, which makes it much easier for the benzylphenol to remove phenol . The remaining amount of benzylphenol in the polycondensate after the distillation of free phenol is actively involved in the processes of oligrhenol curing, sieve and curing of epoxy oligomers. Moreover, the presence of benzylphenol glycidic ester in epoxy oligomers instead of phenylchloride ester helps to reduce the amount of volatile levels of body weight and weight patterns. improvement of processing conditions and physico-mechanical properties of products.

Example 1. In a flask equipped with a stirrer, a reflux condenser, a thermometer and a hydrogen chloride absorption system, 38 g of 2.5-dichloro-p-xylylenedichloro-1, 73 g of phenol and 1 g of zinc chloride are charged. The condensation process is carried out with a gradual increase in the temperature dO until the evolution of hydrogen chloride stops. Duration of the reaction is 7 hours. After completion of the process, the reaction mass is separated from the catalyst-a.

To 100 g of the resulting condensation product, containing 49.5% by weight of free phenol, was added 2.52 g of benzylphenol, which corresponds to 5% by weight with respect to the purified condensation product. Heat the mixture to 190 ° C and at a residual pressure of 5 mm-. Hg Art. the St.-rim phenol is distilled off until cessation at this temperature.

A dark pink rmolo-like product is obtained with a softening point b3-BO C, hydroxyl content of 9–10 wt.%, Bound chlorine content of 19., wt.%. According to the analysis of gas-liquid chromatography, the amount of remaining free phenol in the condensation product is 0.8 wt.% ,. benzylphenol 2.3 wt.% The content of volatile impurities in the epoxy resin, obtained on the basis of this polyphenol 0.83 wt.%.

Example 2. Similar to Example 1, but the amount of benzylphenol added is 3.3 g, which corresponds to 6.5 wt.% With respect to the purified condensation product. Conditions of vacuum CLOSING: T 180 C and GROWTH.

7mm. Hg Art. The softening point of the product is 70-80s, the content of hydroxyl groups is 9-9.7.% By weight, the bound chlorine is 19.0% by weight. The amount of remaining free phenol in the condensation product is 0.38% by weight, benzylphenol is 2.89% by weight. The content of volatile impurities in the epoxy resin obtained on the basis of this polyphenol

0.49 in%

Example 3. Analogous to Example 1, but the amount of benzo-phenol added is 4.05 g, which corresponds to

8 wt.% In relation to the purified product of condensation. Vacuum distillation conditions: T 170 ° C and RSZST. U mm

Art. The softening temperature of the product is 70–85 ° C, the content of hydroxyl groups is 8.8–9.5 wt.%, And the bound chlorine is 19.0 wt.%. The amount of remaining free phenol in the condensation product is 0.1% by weight, benzylphenol is 3.2% by weight. The content of volatile impurities in the epoxy resin obtained on the basis of this polyphenol is 0.3 wt.%.

Example 4. In a flask equipped with a stirrer, reflux condenser, thermometer and hydrogen chloride absorption system, 47 g of 2,3,5,6-tetrachloro-p-xylilend chloride, 71 g of phenol and 1 g of zinc chloride are charged. The condensation process is carried out with a gradual increase in the temperature to 150 ° C until the release of chlorine hydroxide is stopped. Reaction duration: 8 hours. After completion of the reaction.

0 The reaction mass is separated from the catcher.

2.68 benzylphenol was added to 100 g of the obtained condensation product, containing 42.2% by weight of free bodied phenol, which corresponds to 5% by weight with respect to the purified condensation product. The vacuum distillation conditions are the same as in Example 1. A gummy dark brown product is obtained with

0 softening point 90-95 C, containing 6.8-7 wt.%. hydroxyl groups, 31.8 wt.% St. chlorine. The amount of remaining free phenol in the condensation product is 0.85 wt.%

 benzylphenol 2.5 wt.%. The content of volatile impurities in the epoxy resin obtained on the basis of this polyphenol .0,86 wt.%.

0 Example 5. Similar to the example. 4, but the amount of benzylphenol obtained is 3.75 g, which corresponds to 6.5 wt.% with respect to the purified condensation product. The vacuum conditions of the distillation are the same as in Example 2. The softening temperature of the product is 92–97 ° C, the content of hydroxyl groups is 6.5–6.8% by weight, and the bound chlorine is 31.7% by weight. Amount remaining

d of free phenol in the product of condensation 0.46 wt.%, benzylphenol 3.05 wt.%. the content of volatile impurities in the epoxy resin obtained on the basis of this polyphenol 0.45 wt.%.

Example 6. Similar to example 4, but the amount of benzylphenol added is 4.65, which corresponds to 8% by weight relative to the purified condensation product. The vacuum distillation conditions are similar to those in Example 3. The softening temperature of the product is 95-100 s, the content of hydroxyl groups is 6/26, 4 wt.%, And the bound chlorine is 31.5 wt.%. The number of remaining free fe58766626

Zero in the condensation product 0.14 wt.%, Characteristics of solidified obrazobenyl phenol 3.66 wt.%. The contents of epoxy resins obtained on

volatile impurities in epoxy resin based on polyphenols (approx. 1-6) and

polypropylene epoxy resins of the EDH and ETH brand, obtained on the basis of this, at 33% by weight are given in Tables 1 and 2.

Characteristics of hardened epoxy samples

Indicators

Specific impact viscosity, kgf "cm / cm

Static bend, kgf / cm

Brinell hardness, kgf / cm

Heat resistance according to Martens, s

Flame retardant (sample burning time after plunging), s

EDH - epoxy resin according to the author's certificate of the USSR 451723.

Table resins brand EDH

Hardened epoxy resin based on polyphenols

example 3

example 1

example 2

18.3

17.9

17., 2

15.3

1300

1290

1250

1270

28.0

27.9

27.5

27.0

112

110

111

1-3

1-3

1-3

Claims (2)

Claim * ' The method of producing oligophenols by polycondensation of chlorosulfonated in the core of p-xylylenedichloride with phenol in bulk, followed by removal of unreacted Phenol from the obtained oligomer by vacuum distillation at a residual pressure of 5-10 mm. Hg. Art. and 170-190 ° C, I distinguish 45 N and s, in that, in order to reduce the content of volatile impurities in the oligomer and increase the physicomechanical properties of the cured epoxy resins obtained on its basis, they are introduced into the polycondensate before the 50 phenol race 5-8 wt.% (Calculated on the purified oligomer) of benzylphenol. Sources of information mania, _ss taken into account during the examination USSR certificate 08 G 59/04, 1974. USSR certificate 08 G 59/04, 1968 1. Copyright No. 451723, cl. FROM 2. Copyright No. 230415, cl. C (prototype). ВНИИПИ Order 9498/30 Circulation 533 Subscription Branch PPP Patent. Uzhhorod, Project 4,