CN86106758B

CN86106758B - Synthetic method of phenolic resin

Info

Publication number: CN86106758B
Application number: CN86106758A
Authority: CN
Inventors: 赵鸣玉; 李淑贞; 高宏开; 赵鸣一; 李雅洁
Original assignee: Shenyang University of Chemical Technology
Current assignee: Shenyang University of Chemical Technology
Priority date: 1986-10-20
Filing date: 1986-10-20
Publication date: 1988-01-13
Also published as: CN86106758A

Abstract

The present invention provides a new method for synthesizing phenolic resin without generating waste water containing phenol. The method is a semi-closed circulating technological process comprising two parts namely a condensation reaction and a polycondensation reaction. Firstly, methanol and formaldehyde have a continuous condensation reaction to obtain intermediate methylal mixed with phenol to generate a polycondensation reaction in an acidic medium to obtain phenolic resin, and no waste water containing phenol is generated in the reaction. The by-product of methanol can be used for preparing the methylal, and the other by-product of phenol can be used as raw materials for the synthesizing the resin. The purity of the intermediate methylal is larger than 92%, and the yield of the phenolic resin is higher than 98%.

Description

A kind of synthetic method of resol

The invention belongs to the synthetic method of organic high molecular compound, be applicable to and produce resol.

Resol has good acidproof, alkaline-resisting, heat-resisting and electrical insulating property, is widely used in many aspects such as telecommunication, electrical equipment, instrument, daily necessities, light building material.Synthetic adopt usually " formaldehyde method " of past resol, promptly polycondensation in acidic medium forms thermoplastic lacquer resins by phenols and formalin, or polycondensation becomes heat-reactive phenolic resin in alkaline medium, and its reaction formula is:

（n+1）C ₆H ₅OH+nCH ₂O

C ₆H ₄OH+nH ₂O

The main drawback of this method is to react a large amount of phenolic wastewater of generation, one ton of resin of common every production will produce 0.6～0.8 ton of waste water that contains the phenol amount up to 30,000 mg/litre, need the cost huge investment to carry out sewage disposal, because phenolic wastewater treatment technology level is limited at present, therefore still environment is caused certain pollution.

Provided by the present inventionly produce the technology of resol by methylal and phenols, WPI and WPLL database retrieval through U.S. ORBIT system prove that forefathers did not study as yet.

The novel process of producing resol that the object of the present invention is to provide simple, the no phenolic wastewater of a kind of technology to generate.

The present invention divides two steps to implement: i.e. the preparation of the continuous condensating of methylal and resin.Existing division is as follows:

1, the continuous condensating of methylal

With methyl alcohol and two kinds of solution of formaldehyde in molar ratio 2.0～2.5 ratio be mixed with mixed solution, after being preheating to 40～60 ℃, be passed into the built-up type conversion zone, in temperature is under 65～90 ℃, by means of the catalysis and the centrifugation of Zeo-karb, carries out the continuous condensating reaction, resultant of reaction is under the effect of hot-fluid, be separated the stable ternary azeotrope of composition through built-up type conversion zone and stripping section, wherein the concentration of methylal is generally 93.5% more than or equal to 92%.In addition, feed methyl alcohol again from conversion zone bottom and continue to react, make in the still liquid formaldehyde residual volume smaller or equal to 100ppm with unreacted a small amount of formaldehyde.

Principal reaction is:

2CH ₃OH+HCHO

（CH ₃O） ₂-CH ₂+H ₂O

2, resin is synthetic

With methylal and phenol in molar ratio 0.7～0.95 proportioning mix, add an acidic catalyst (hydrochloric acid, sulfuric acid) down at 40～60 ℃, temperature of reaction is controlled at 65～75 ℃, polycondensation is 3～7 hours under normal pressure, reactant is after concentrating, air distillation removes methyl alcohol, and underpressure distillation removes phenol again, promptly obtains water white transparency or milky resin.The cut that contains methyl alcohol, minor amount of water and a small amount of methylal more than 85% that air distillation goes out, as the raw material of system methylal, the cut based on phenol of underpressure distillation gained, the raw material as synthetic resins recycles.Owing to contain less water (because of bringing in hydrochloric acid or the sulfuric acid) in the reduced pressure distillate, in recycling, will cause water small amount of accumulation during the course, can burn by distillation discharge system.The productive rate of gained resol is more than 98%.

Principal reaction is:

+ (CH ₃O) ₂CH ₂→ resin+2CH ₃3OH

The technological process of invention sees Fig. 1 for details.

Fig. 1 is an acetal method novolak resin process flow diagram.

The invention provides a kind of new method of producing resol, technological process is simple, in reaction process, in raw material, bring anhydrous generation the less water into, by product recycles in system, entire reaction is semiclosed working cycle, avoided " formaldehyde method " a large amount of phenolic wastewater that technology produced to handle, phenolic waste liquor has been eliminated in technological process, not the output three wastes.The method of serialization synthesizing dimethoxym ethane not only provides the ideal intermediate for resol, has also promoted C ₁The methyl alcohol CHEMICAL DEVELOPMENT.Technical indicator advanced person, methylal concentration is greater than 92%, and the resol productive rate is more than 98%, softening temperature＞95 ℃, poly-speed 40～60 seconds, viscosity 30～40 seconds (No. four cups) contains phenol amount＜6%.The resol that resol provided by the present invention and formaldehyde method are produced is different on the end-group structure of macromolecular chain, and the former is ehter bond-methoxyl group (OCH ₃), the latter is alcoholic extract hydroxyl group (CH ₂OH), therefore, the resin that the present invention obtained also has the characteristics of good fluidity.

The embodiment of the invention is as follows:

Producing of methylal

At first add methanol solution on mixing tank top, the device bottom feeds formaldehyde, the ratio of components that makes methyl alcohol and formaldehyde is 2.2 moles, after the mixing, be preheating to 45～60 ℃, add the built-up type conversion zone, under 75～90 ℃,, carry out condensation reaction by means of catalysis, the centrifugation of Zeo-karb (732 types, 1000 milliliters).In the resultant of reaction, methylal is separated into the stable ternary azeotrope of composition well through knockdown distilling period under the hot-fluid effect, unreacted formaldehyde completely further reacts through the small amount of methanol of adding bottom conversion zone again, last discharge at the bottom of the still of water sepn section, this liquid effluent is for absorbing the formaldehyde water, and methylal concentration is＞92% in the cat head production fluid.

Synthesizing of resin

In the reactor that agitator, prolong and thermometer are housed, adding purity restrains greater than 99% phenol 144, methylal 103.8 grams of purity 93.7% when under agitation being heated to 50～60 ℃, stop heating, slowly splashing into 7.7 milliliters of hydrochloric acid (proportion 1.16) must begin to descend by temperature of charge, under agitation reflux is after 4 hours, adds solid sodium hydroxide 1.5 grams, treat the solid caustic soda dissolving after, earlier under normal pressure, boil off methyl alcohol, carry out underpressure distillation then.When temperature rose to 160 ℃, blowing got the water white lacquer resins of softening temperature more than 90 ℃, and productive rate is 98%.

Resin properties sees Table 1

Table 1 resol character

Outward appearance	Viscosity (No. four cups) second	Poly-fast second	Softening temperature ℃	Contain phenol amount %
					Water white transparency (slightly little yellow or oyster white)	30～40	40～60	＞95	＜6%

Claims

1, a kind of synthetic method of resol, it is characterized in that with the methylal being that raw material and phenol polycondensation form, methylal is by formaldehyde and methanol mixed, be preheated to 40～60 ℃, in temperature of reaction is under 65～90 ℃, catalysis by Zeo-karb, centrifugation, carry out the serialization condensation reaction, obtain forming the stable ternary azeotrope based on methylal through fractionation by distillation again, water is discharged at the bottom of the tower still, for absorbing the formaldehyde water, methylal is mixed by a certain percentage with phenol, under 40～60 ℃ of temperature, add the concentrated hydrochloric acid or the vitriol oil while stirring, 65～75 ℃ of following polyreactions 3～7 hours, through distillation, refining water white transparency or the milky resin of obtaining, reclaim the raw material of solvent methanol solution as the system methylal, phenol recycles as the raw material of synthetic resins.

2, resol synthetic method according to claim 1 is characterized in that the mol ratio of methyl alcohol and formaldehyde is 2.0～2.5 in the condensation reaction.

3, resol synthetic method according to claim 1 is characterized in that the mol ratio of methylal and phenol is 0.7～0.95 in the polycondensation.

4, according to claim 1 and 2 described resol synthetic methods, it is characterized in that in the condensation reaction, replenish methyl alcohol from the conversion zone bottom.