JP2002348346A - Method for manufacturing novolak resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a phenol novolak resin improved in equipment productivity by efficiently removing the heat of reaction under pressure. SOLUTION: The method for manufacturing a phenol novolak resin comprises reacting a phenol with an aldehyde in a pressurized state, where the reaction is effected with the pressure adjusted so that water or an organic solvent present in the system is refluxed while removing the heat of reaction by a condenser. Preferably, formaldehyde is employed as the aldehyde in the manufacturing method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a phenolic novolak resin, and more particularly, to a method for producing a phenolic novolak resin by reacting a phenol and an aldehyde under a pressurized state. .

[0002]

2. Description of the Related Art Phenolic novolak resins are used in a wide variety of fields such as molding materials, epoxy resin curing agents, photoresist resins, and epoxy resin raw materials. Such phenolic novolak resins are generally reacted under normal pressure (phenol resin: pages 83 to 85, 1987, published by Plastic Age Co., Ltd.). On the other hand, a method of reacting under pressure is also known. For example, a method of obtaining a high orthonovolak resin by reacting under pressure using an organic solvent (Makromol. Chem. 182,2973 (1981), Japanese Patent Application Laid-Open No. 2000-26494)
No. 1 publication has been proposed.

[0003] When phenolic novolak resins are produced on an industrial scale, a method of removing the heat of reaction becomes a problem.
Even in the case of a reaction under normal pressure, the cooling efficiency is poor due to the high viscosity in the reaction system and the use of a glass lining tank for the reaction under acidic conditions. In general, the reaction is carried out while refluxing water or an organic solvent existing in the reactor by removing heat in a condenser.

On the other hand, in the case of a reaction under pressure, even if a condenser is attached, reflux does not occur probably due to the presence of the inert gas used at the time of raw material preparation, and it is difficult to remove heat of reaction. For this reason, a method of reducing the amount of the raw material charged or a method of dropping aldehydes little by little and reacting for a long time has been adopted so as to match the cooling capacity of the reaction tank jacket. However, the former method has a problem that the production amount per reaction tank is small, and the latter method has a problem that the reaction time is long, and both methods are inferior in equipment productivity. Therefore, an object of the present invention is to provide a method for producing a phenolic novolak resin under pressure, and to provide a production method in which equipment productivity is improved by efficiently removing heat of reaction.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, in the reaction between phenols and aldehydes under pressure, the pressure in the system was adjusted. Found that the phenolic novolak resin can be produced with good equipment productivity by recirculating water or an organic solvent present in the phenol, and the present invention was completed. That is, the present invention provides a method for producing a phenolic novolak resin in which a phenol and an aldehyde are reacted in a pressurized state. An object of the present invention is to provide an industrially excellent method for producing a phenolic novolak resin, wherein the reaction is carried out while removing the heat of reaction.

The phenols used in the present invention are not particularly limited. Examples thereof include phenol, a substituted phenol having a substituent such as an alkyl group having 1 to 9 carbon atoms, halogen, an aromatic group, resorcinol, hydroquinone,
And polyhydric phenols such as phloroglysin. Here, in the case of a phenol having a substituent, the number of the substituent is usually 1 to 3, and at least three of the three reactive positions (para position and two ortho positions with respect to the phenolic hydroxyl group) Two substituted phenols which are unsubstituted are preferably used. Particularly, bifunctional phenols such as orthocresol are preferred from the viewpoint of reactivity and the like.

The aldehydes used in the present invention include, for example, formaldehyde, acetaldehyde, butyraldehyde, benzaldehyde, hydroxybenzaldehyde, acrolein, glyoxal and the like. In the case of formaldehyde, formalin, paraform, trioxane and the like can also be used. Among them, formalin is preferred from the viewpoint of handleability and the like. The amount of the aldehyde used depends on the molecular weight of the target phenolic novolak resin,
Usually, it is 0.5 to 0.99 mole times.

Although the present invention can be carried out without a catalyst, an acidic catalyst can also be used. As the acidic catalyst, a commonly used catalyst can be used. Specific examples include mineral acids such as hydrochloric acid and sulfuric acid, organic acids such as toluenesulfonic acid and oxalic acid, and salts such as zinc acetate. The amount of the catalyst to be used is usually 0.001 to 0.1 mol times to the phenols.

In the present invention, an organic solvent can be used if necessary. As the solvent, a solvent in which the raw material and the product are soluble is preferable, and for example, an aromatic solvent such as xylene and toluene can be used.

When the reaction is carried out in a pressurized state, a method in which the reaction system is replaced with an inert gas at normal temperature, the system is closed, and then the temperature is raised to a predetermined temperature to bring it to a pressurized state. There is a method of sealing after heating and introducing an inert gas into a pressurized state. In the present invention, any method can be adopted,
In any case, because of the presence of the inert gas, even at a temperature equal to or higher than the boiling point of a low-boiling component such as water or an organic solvent, no boiling occurs and no reflux occurs. Therefore, in the present invention, depressurization, that is, purging with an inert gas to boil low-boiling components so that reflux occurs, and reacting the low-boiling components while removing heat with a condenser.
The depressurization may be during the heating or after the heating,
What is important is that, at a predetermined temperature, the pressure is reduced so that low-boiling components are refluxed. Usually, it is sufficient to perform it once, but it can be performed a plurality of times. In the case of reacting while adding aldehydes in the absence of low boiling components, even if the pressure is released in the early stage of the reaction, the generation of water, which is a low boiling component, is small, and almost no reflux is observed. Reflux with it. In such a case, it is also possible to release the pressure after a low-boiling component has accumulated to some extent.

After the reflux has begun, the pressure is preferably adjusted to a constant value. The pressure varies depending on the type of the raw material and the like, but is usually about 0.01 to 2.3 MPa, preferably about 0.05 to 0.50 MPa. In order to adjust the pressure to a constant value, for example, the pressure may be controlled using a constant pressure device having a purge valve and an inert gas introduction valve.

The reaction temperature is usually from 110 to 220 ° C, preferably from 110 to 160 ° C, more preferably from 120 to 150 ° C. If the temperature is too low, the reaction rate tends to slow down,
On the other hand, if it is too high, side reactions such as decomposition of the raw material tend to occur, and any case is not preferable. The ortho ratio can be controlled by changing the reaction temperature.
That is, the ortho ratio increases when the reaction is performed at a high temperature, and decreases when the reaction is performed at a low temperature. The ortho ratio can be determined by analyzing a binuclear substance by gas chromatography.

The present invention can be implemented, for example, as follows. Phenols and, if necessary, a catalyst are charged into an autoclave equipped with a thermometer and a stirrer. Then, the pressure is released at a predetermined temperature, water or an organic solvent is refluxed, and aldehydes are added continuously or discontinuously, and the temperature is kept until the reaction is completed. Furthermore,
To shorten the reaction time, an acidic catalyst may be additionally charged. Thereafter, if necessary, neutralization with an alkali, washing with water, dehydration under reduced pressure, and stripping are performed to obtain a phenolic novolak resin.

[0014]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the examples. In addition,
The measuring method and the like in the examples are as follows. Ortho ratio: 3 types of binuclear isomers (ortho-ortho, ortho-para, para-para) by gas chromatography
The ratio was measured, and the ratio was determined as ortho ratio (%) = ortho-ortho body (%) + ortho-para body (%) / 2. Softening point: measured by a ring & ball method. Yield: Calculated assuming that (weight of phenols + weight of formaldehyde × 12 ÷ 30) is 100%.

Comparative Example 1 75.6 kg of orthocresol and 882 g of oxalic acid (dihydrate) were placed in a jacketed pressure-resistant GL container (300 L) equipped with a thermometer, a stirrer, a condenser and a formalin injection pump and dissolved. The atmosphere was replaced with nitrogen, sealed, and the temperature was raised to 130 ° C. At this time, the pressure was 0.05 MPa. 33.6% formalin 23.6 k
Injection was started at a rate of g / hr. Immediately after the dropping, a temperature rise due to heat generation was observed, and the mixture was cooled in the jacket. However, the temperature gradually increased, and after 1 hour and 10 minutes, when 27.5 kg of formalin was injected, the temperature reached 140 ° C., so the injection of formalin was stopped. At this time, the pressure was 0.37 MPa. 130 ° C over 30 minutes
(Pressure 0.28 MPa), formalin injection was resumed, and 19.7 kg was charged over 50 minutes. During this time, no large heat generation was observed, and the temperature was 130 ± 5 ° C (pressure 0.27 to 0.31 MPa). The mixture was further stirred at the same temperature for 4 hours. Then 85 ° C
After cooling to normal pressure and neutralization with 10% sodium hydroxide solution. After washing with water, water and unreacted monomers were removed by distillation under reduced pressure.
m or less to obtain 82.1 kg of ortho-cresol novolak resin (yield 99.4%). The ortho ratio was 42% and the softening point was 110 ° C.

Example 1 The same device as used in Comparative Example 1 was equipped with a constant pressure device (a device for keeping the pressure constant by a purge valve and a nitrogen injection valve), and 75.6 kg of orthocresol and oxalic acid (dihydrate) were used. )
After charging and dissolving g, the atmosphere was replaced with nitrogen, sealed, and heated to 130 ° C. At this time, the pressure was 0.05 MPa. Injection of 37.6% formalin was started at a rate of 23.6 kg / hr. 40 minutes later, 16.7 kg of formalin was injected, and 135 ° C (pressure 0.32 MPa)
When the pressure reaches, the purge valve is opened, depressurized, and
Controlled with a. Thereafter, 33.0 kg of formalin was injected over 80 minutes. During this time, reflux occurred and the temperature stabilized at 130 ± 1 ° C. The mixture was further stirred at the same temperature for 4 hours. Thereafter, the same treatment as in Comparative Example 1 was carried out to obtain 82.5 kg of ortho-cresol novolak resin (yield 99.3%). Ortho ratio is 41
%, Softening point was 124 ° C.

Example 2 In Example 1, after injecting formalin, instead of keeping the temperature for 4 hours, keeping the temperature for 1 hour, adding 1.33 kg of a 50% aqueous solution of paratoluenesulfonic acid (monohydrate), and keeping the temperature for 1 hour. Except for the above, the same procedure as in Example 1 was carried out to obtain 82.6 kg of orthocresol novolak resin (yield: 99.4%). Ortho ratio is 42
%, The softening point was 123 ° C.

Example 3 The same apparatus as in Example 1 was charged with 75.6 kg of orthocresol, 882 g of oxalic acid (dihydrate), and 10 kg of pure water and dissolved. did. At this time, the pressure was 0.32 MPa. The purge valve was opened, depressurized, refluxed, and controlled at 0.19 MPa. 39.7% formalin 49.7kg
Was injected over 2 hours at a rate of 23.6 kg / hr. During this time,
The temperature stabilized at 130 ± 1 ° C. Thereafter, the same treatment as in Example 2 was performed, and 82.7 kg of ortho-cresol novolak resin (yield:
99.6%). The ortho ratio was 43% and the softening point was 124 ° C.

[0019]

According to the production method of the present invention, the reaction heat can be efficiently removed, the phenolic novolak resin can be produced with good equipment productivity, and the method of the present invention can be carried out on an industrial scale. It becomes advantageous in. Further, according to the method of the present invention, since the fluctuation width of the reaction temperature is reduced, a product of stable quality can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Koji Yano, Inventor, 5-1 Sokai-cho, Niihama-city, Ehime Prefecture F-term in Sumitomo Chemical Co., Ltd. 4J033 CA02 CA09 CA12 CB25

Claims (4)

[Claims] In a method for producing a phenolic novolak resin in which a phenol and an aldehyde are reacted in a pressurized state, the pressure is adjusted so that water or an organic solvent present in the system is refluxed, and the pressure is adjusted by a condenser. A method for producing a phenolic novolak resin, wherein the reaction is carried out while removing heat of reaction. 2. The method according to claim 1, wherein the aldehyde is formalin.
Manufacturing method. 3. The method according to claim 1, wherein the phenol is orthocresol. 4. The process according to claim 1, wherein the phenol novolak resin has an ortho ratio of 30 to 60%.