JPH09241346A - Production of novalac phenol resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a novolac phenol resin at good efficiency by increasing the rate of the addition condensation reaction and simultaneously performing dehydration by increasing the efficiency of mixing a phenol with a formaldehyde. SOLUTION: In a process for producing a novolac phenol resin by reacting a phenol with an aldehyde in the presence of a catalyst in such a manner that the mixture of the phenol with the catalyst is mixed with the aldehyde while keeping the temperature of the mixture at 105-180 deg.C to simultaneously effect the addition condensation reaction and dehydration, the mixture of the phenol with the catalyst is quantitatively mixed with the aldehyde in a specified molar ratio with a static mixer 4 and/or a turbine pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a novolak type phenolic resin, and particularly to increase the rate of addition condensation reaction by keeping the reaction temperature above the boiling point of water and increasing the mixing efficiency of phenols and formaldehydes. In addition, the present invention relates to a method for efficiently producing a novolac type phenolic resin which can be dehydrated simultaneously.

[0002]

2. Description of the Related Art Conventionally, novolak type phenol resins are
After conducting an addition condensation reaction of phenols and aldehydes under a known acidic catalyst using a reactor at atmospheric pressure of 100 ° C. for 60 to 180 minutes, water in the raw material and condensed water generated by the condensation reaction are atmospherically pressured. Alternatively, a method of evaporating and removing by applying 120 to 240 minutes under reduced pressure was general. Further, if necessary, a step of removing unreacted substances may be added, but in such a method, the problem that the reaction and dehydration steps take time, and the raw water and the condensed water, which are originally reaction-inhibiting substances, simultaneously react in the reaction solution. However, there is a problem that the reaction rate is reduced because it is contained in the inside. In addition to the resin, it is necessary to consider the capacities of the raw material water and the condensed water, and there is a problem that the yield relative to the capacity of the reactor is small.

On the other hand, as a method for simultaneously performing the reaction and the dehydration, a method of adding a hydrophobic solvent to the reaction system to separate water (for example, JP-A-245010, JP-A-1-6016, etc.) or phenols in advance A method is known in which a mixture of aldehyde, aldehyde and a catalyst is reacted in a pipe and dehydrated in an evaporator (for example, Japanese Patent Application Laid-Open No. 51-130498). In the former method, water is replaced after the reaction is completed. In addition to the need for a step of removing the solvent, there is a problem that odor and deterioration of resin characteristics are caused by a slight residual solvent. The latter is a generally-known continuous reaction, and it is necessary to homogenize all the main raw materials and catalysts in the mixing tank in advance because of the reaction in the pipe that does not have a mixing effect. Therefore, there is a problem that a zone for raising the temperature step by step is required, the reaction rate is slow, and the reaction pipe requires a distance of 5,000 to 50,000 per tube diameter 1.

Further, there is known a method of simply dehydrating phenols while adding aldehydes (JP-A-3-281617). In this method, however, the reaction rate is maintained because a predetermined amount of water is maintained in the reaction system. When the addition of aldehydes is performed from above the liquid surface, the aldehydes are evaporated on the reaction liquid surface before the reaction is sufficiently carried out, and there is a problem not only in the yield but also in the environment. Further, as a method for increasing the reaction rate, a method by a high pressure reaction using an autoclave (for example, JP-A-4-356515)
However, there is a problem in that water still exists in the reaction system, the pressure-reducing step takes time, and the facility investment for ensuring safety is large.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted extensive studies to solve these problems, and as a result, by mixing aldehydes in a mixture of heated phenols and a catalyst, and further mixing them. By using a static mixer and / or turbine pump for the equipment, the addition condensation reaction is completed in a short time without using a solvent that is simple in equipment and does not participate in the reaction, and at the same time, the raw water and the condensed water are The present invention has been completed by finding that it can be removed by evaporation and a novolac type phenol resin can be obtained efficiently.

[0006]

According to the present invention, when a phenol is reacted with an aldehyde in the presence of a catalyst, the aldehyde is added while maintaining the temperature of the mixed solution of the phenol and the catalyst at 105 to 180 ° C. In a method for producing a novolak type phenol resin in which dehydration is performed at the same time, a static mixer and / or a turbine pump are used for mixing both liquids.

As the phenols, one or more compounds having a phenolic hydroxyl group such as phenol, cresol and bisphenol are used, and the aldehydes are aldehyde groups such as formaldehyde, paraformaldehyde and polyoxymethylene. 1 type (s) or 2 or more types of the compound which has are used. Although the molar ratio of the aldehyde to the phenol is not particularly limited, it is generally in the range of 0.3 to 1.0. As the catalyst, one or more of inorganic or organic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, oxalic acid, maleic acid, p-toluenesulfonic acid and sulfamic acid are used.

The mixing of the phenols and the catalyst and the temperature rise are carried out in a known reactor having a stirrer and a heating device, and the temperature at this time is 105 to 180 ° C. Depending on the catalyst species, the decomposition temperature or sublimation temperature may be the upper limit, but 105 ° C
In the following, not only the reaction rate is slow, but also raw material water and condensed water cannot be completely evaporated and removed. Further, at 180 ° C. or higher, the reaction rate is fast and it is difficult to suppress partial polymer formation. In addition, if necessary, oxidation can be prevented by an inert gas according to a conventional method. This mixed solution is supplied by a metering pump or the like.

The static mixer used in the present invention has a mixing blade such as a twisting blade (FIG. 3) or a folding blade (FIG. 4) inside the pipe, and the fluid is repeatedly divided when passing through the inside. -It is mixed. The turbine pump used in the present invention has an internal structure as shown in FIG. 5, and includes a vane (12) on which a fluid rotates and a pump body (1).
It flows while swirling between 3) and the mixing action works at this time. (11) and (11 ′) are fluid inlets,
(14) is a fluid outlet. The types of the static mixer and the turbine pump are not particularly limited, but it is preferable that the static mixer has two or more blades and the turbine pump has two or more turbines in view of the mixing effect. When both are used in combination, it is more preferable to dispose the turbine pump in the front stage and the static mixer in the rear stage.

The mixing time for determining the length of the static mixer or the rotation speed of the turbine pump, in other words, the reaction time varies depending on the temperature of the mixed solution and the molar ratio of aldehydes / phenols, but is limited in the present invention. As long as it is within a temperature range, it is sufficient to secure several seconds to 1 minute. Even if the mixing time is made longer than this, the addition condensation reaction is completed and there is no effect, and the static mixer has a large pressure loss, and the turbine pump leads to a decrease in production efficiency due to a decrease in flow rate. Does not match.

Aldehydes are quantitatively supplied in an amount corresponding to the desired molecular weight, but the feed position is preferably just before the inlet of the static mixer or turbine pump, and further, the phenols and the catalyst are added. It is preferable to supply from the center of the flow path along the advancing direction of the mixed solution.
When the supply position is farther from the mixing device, the mixing degree is different due to the difference in the flow velocity between the tube wall and the central portion, and a partial polymer is likely to be produced.

The mixed solution may be returned to the original reactor or may be transferred to the second reactor or a known thin film evaporator. In any case, the raw material water and the condensed water evaporate at the moment when they come out of the mixing device. Further, at this time, the mixed solution may be sprayed with a spray nozzle or the like in order to secure an evaporation area, and the second reactor and the thin film evaporator may be at normal pressure, or more preferably reduced pressure. If necessary, unreacted phenol is further removed to obtain a novolac type phenol resin.

Further, an example of the present invention will be described in detail with reference to FIG. 1, but the present invention is not limited by such description. FIG. 1 is a schematic diagram showing the equipment and flow using a static mixer. After supplying the phenols and the catalyst to the first reactor (1) with a stirrer, while mixing, 105 to 18
Heat to 0 ° C. After reaching the temperature, the mixed liquid is supplied to the static mixer (4) by the metering pump (2). At the same time, the aldehydes are supplied from the aldehydes supply facility (3) to the static mixer in an amount that provides a predetermined molar ratio. In the static mixer (4), quantitatively mixed, an addition condensation reaction of phenols and aldehydes is performed, and water and condensed water in the raw materials are evaporated and vaporized, and the transfer pipe (5) is in a gas-liquid mixed state. To the second reactor (6). At this time, the water vapor is immediately separated at the entrance of the second reactor, condensed by the heat exchanger (7) and removed to the outside of the system, and only the dewatered novolac-type phenol resin is stored in the second reactor (6). To be done. After this, if necessary, unreacted phenol may be removed by a known method.

Further, as shown in FIG. 2, the reaction liquid in a gas-liquid mixed state discharged from the static mixer (4) is returned to the first reactor (1) by a transfer pipe (8) and circulated so that water vapor is generated. Even if it is condensed by the heat exchanger (9), the intended effect can be obtained.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited by these examples. In addition, all "%" described in the text indicates% by weight.

Example 1 A solution prepared by heating 85.0 kg of phenol and 0.8 kg of oxalic acid to 130 ° C. in a 100 L capacity first reactor equipped with a heating device and a stirrer was heated by a gear type constant pump to 5 The amount of 0.7 kg / min was supplied to a static mixer having 10 stages of twisting blades inside. At the same time, 37% formalin was also supplied at a rate of 3.9 Kg / min for reaction. After that, it was sent to a second reactor having a heat exchanger with a capacity of 100 L and the steam was condensed and removed to obtain 86.0 kg of novolac type phenol resin. The obtained resin had a weight average molecular weight of 3200, unreacted phenol of 4.8% and water content of 0.
7% and unreacted formaldehyde 0.05%. Also, it took 15 hours to process 85 kg of phenol.
Minutes. The weight average molecular weight was measured by high performance liquid chromatography, unreacted phenol was quantified by capillary gas chromatography, water was quantified by Karl Fischer reagent titration, and unreacted formaldehyde was quantified by hydroxyamine hydrochloride titration. It was The same applies to the following examples and comparative examples.

Example 2 Phenol 85.0 kg, 1
A solution obtained by heating 0.4 kg of 0% hydrochloric acid to 110 ° C. in a reactor having a capacity of 100 L equipped with a heat exchanger, a heating device, and a stirrer at a rate of 25.5 kg / min. Supply to a mixer, 37% formalin at the same time 5.9Kg
The amount of / min was supplied and reacted. The reaction solution was returned to the original reactor, and this operation was continuously carried out for 10 minutes while condensing water vapor in the heat exchanger and removing it from the system to obtain 83 kg of novolac type phenol resin. The obtained resin had a weight average molecular weight of 5,300, unreacted phenol of 5.3%, and water content of 1.
It was 0% and unreacted formaldehyde 0.07%. The time required for the reaction was 10 minutes.

Example 3 Of the equipment used in Example 1, the static mixer was a three-stage turbine pump, the supply amount of phenol and catalyst mixed liquid was 4.3 Kg / min, and the supply amount of formalin was 3. Novolak type phenol resin 8 was prepared in the same manner as in Example 1 except that the pressure was 0 kg / min.
6 kg was obtained. The obtained resin has a weight average molecular weight of 420.
0, unreacted phenol 6.5%, water content 1.5%, unreacted formaldehyde 0.05%. The time required for the reaction was 20 minutes.

Example 4 The temperature of the mixed solution of phenol and catalyst was 145 ° C., the supply rate of the mixed solution was 8.5 Kg / min, and the formalin supply rate was 5.7 Kg / min. Novolak type phenolic resin 8 by the same method
3 kg was obtained. The obtained resin has a weight average molecular weight of 350.
0, unreacted phenol 3.8%, water content 0.5%, unreacted formaldehyde 0.05%. The time required for the reaction was 10 minutes.

Example 5 Phenol 45 kg, bisphenol A 44.0 kg, and oxalic acid 1.3 kg 140 g
Supply at 27Kg / min at ℃, 3.7K formalin supply
The novolac-type phenol resin (89 kg) was obtained in the same manner as in Example 2 except for g / min. The obtained resin has a weight average molecular weight of 4100, unreacted phenol of 2.7%,
The water content was 0.9% and the unreacted formaldehyde was 0.08%. The time required for the reaction was 10 minutes.

Example 6 The pressure in the second reactor was reduced to 60.
By the same method as in Example 1 except that Torr was used, 84 Kg of novolac type phenol resin was obtained. The resin obtained had a weight average molecular weight of 3400 and unreacted phenol of 0.8.
%, Moisture 0.3%, unreacted formaldehyde 0.03%
Met. The time required for the reaction was 15 minutes.

Comparative Example 1 The reactor used in Example 2 was charged with 60.0 kg of phenol and 0.6 kg of oxalic acid.
After heating to 00 ℃, 37% formalin 35.0Kg
Was gradually added over 90 minutes, and the reaction was continued at 100 ° C. for 60 minutes. The weight average molecular weight at this time was 1700, unreacted phenol was 9.5%, water content was 23.2%, and unreacted formaldehyde was 3.5%. When this resin was dehydrated while heating it to a temperature of 130 ° C, 21
It cost 0. At this point, the weight average molecular weight was 3,500, unreacted phenol was 8.5%, water content was 2.3%, and unreacted formaldehyde was 0.35%. The resin obtained is 59
Kg.

Comparative Example 2 The same procedure as in Example 1 was carried out except that the temperature of the mixed solution of phenol and oxalic acid was changed to 80 ° C., and before the entire amount in the first reactor was treated, The second reactor was full and no further processing was possible. The resin obtained at this point has a weight average molecular weight of 2
400, unreacted phenol 8.5%, water 13.5
%, Unreacted formaldehyde was 1.5%.

Comparative Example 3 A novolac type phenolic resin was obtained in the same manner as in Example 1 except that the static mixer section was replaced with normal piping. The obtained resin had a weight average molecular weight of 1700, but a peak was observed in the high molecular region. Unreacted phenol 9.0%, moisture 6.2
%, Unreacted formaldehyde was 3.5%. Further, when the inside of the pipe was checked, a polymer scale was attached to the pipe wall.

As is clear from these Examples and Comparative Examples, the novolac type phenol resin obtained by the method of the present invention not only completes the addition condensation reaction of phenols and aldehydes in a short time, but also at the same time. Dehydration is also virtually complete. It is also clear that the resin yield per volume of the reactor can be increased.

[0026]

According to the method of the present invention, since the reaction temperature is raised and water which is a reaction inhibitor is removed at the same time,
The reaction rate of phenols and aldehydes can be made extremely fast, and there is no problem with the conventional problems of large installation area and scale generation due to partial overreaction in the reaction process. Since it can be fully utilized, it is suitable as an industrial method for producing a novolac type phenol resin.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the equipment and flow when a static mixer is used in the present invention using a first reactor and a second reactor.

FIG. 2 is a schematic diagram showing the equipment and flow when only a first reactor is used and a static mixer is used in the present invention.

FIG. 3 is a perspective view of blades of a static mixer having a twisting blade inside the pipe.

FIG. 4 is a perspective view of blades of a static mixer having folding blades inside a pipe.

FIG. 5 is a perspective view showing the internal structure of a turbine pump.

[Explanation of symbols]

 1 First Reactor 2 Metering Pump 3 Aldehyde Supply Device 4 Static Mixer 5 Transfer Pipe to Second Reactor 6 Second Reactor 7 Heat Exchanger 8 Transfer Pipe to First Reactor 9 Heat Exchanger 11, 11 'fluid inlet 12 vanes 13 pump body 14 fluid outlet

Claims (1)

[Claims] 1. When the phenols are reacted with the aldehydes in the presence of the catalyst, the addition condensation reaction is carried out by mixing the phenols and the catalyst with the aldehyde while keeping the temperature of the mixed solution at 105 to 180 ° C. In a method for producing a novolac type phenol resin which is dehydrated at the same time, a mixed solution of phenols and a catalyst and aldehydes are quantitatively mixed at a predetermined molar ratio by a static mixer and / or a turbine pump. A method for producing a novolac type phenolic resin.