JPS5823404B2 - Manufacturing method of phenolic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novolac type phenolic resin.

Molded products made of novolac type phenolic resin are widely used because they are inexpensive and have excellent mechanical and thermal properties.

The molding material is generally made by adding a base material such as wood flour, glass fiber, asbestos, a hardening agent such as hexamethylenetetramine, etc. to a resin and kneading the mixture with rolls.

This molding material is cured in the mold under heat and pressure to form a molded product.

By the way, if the softening point of the resin used is too high, the workability during roll kneading will be poor and the fluidity during molding will also be poor, making it impossible to obtain a molded product of good quality.

Therefore, in such cases, it is necessary to lower the softening point of the resin used.

However, when phenols and aldehydes are reacted, the softening point when most of the aldehydes have reacted is the molar ratio A/
It is almost determined by P, and is not related to the type and amount of the acid catalyst used, the reaction temperature and pressure, and the concentration of aldehydes.

Therefore, if the above problem occurs with a phenolic resin reacted at a certain molar ratio A/P, it is necessary to use a plasticizer or add a solvent such as methanol, phenol, or methyl cellosolve that is compatible with the resin. is possible.

However, the use of plasticizers may deteriorate the performance of the molded product, and on the other hand, the addition of solvents may generate gas during molding, which may deteriorate the heat resistance, mechanical strength, dimensional stability, etc. of the molded product. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for producing a novolac type phenolic resin that makes it possible to lower the softening point without causing problems such as deterioration of molded product performance.

The present invention is characterized in that the softening point of the phenol resin is lowered by reacting phenols and aldehydes under an acid catalyst, and then adding a monofunctional epoxyalkyl compound to cause the reaction. The gist is the manufacturing method of resin.

The so-called phenols mentioned above include phenol, cresol, xylenol, etc., the aldehydes include formaldehyde, furfural, acetaldehyde, etc., and the acid catalysts include hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, oxalic acid, boric acid, phosphoric acid, etc. All of these are commonly used as raw materials for producing novolac type phenolic resins.

Among aldehydes, formaldehyde may be of any concentration, such as formalin or paraform.

The molar ratio A/P of aldehydes to phenols is 1
, 0, there is a possibility that the resin will gel, and the softening point will also become high, resulting in poor roll kneading properties during molding.

Examples of the monofunctional epoxyalkyl compounds include methyl glycidyl ether, ethyl glycidyl ether, isopropyl glycidyl ether, butyl glycidyl ether, isobutyl glycidyl ether, tert-butyl glycidyl ether, pentyl glycidyl ether, impentyl glycidyl ether, and tert-pentyl glycidyl ether. , hexyl glycidyl ether, heptyl glycidyl ether, octyl glycidyl ether, nonyl glycidyl ether, 2-methyloctyl glycidyl ether, C13C14 mixed glycidyl ether, C14-Cl3 mixed glycidyl ether, cyclopropyl glycidyl ether, cyclobutyl glycidyl ether, cyclopentyl glycidyl ether , cyclohexyl glycidyl ether, vinyl glycidyl ether,
flopenyl glycidyl ether, butylenyl glycidyl ether, pentenyl glycidyl ether, cyclopropyl glycidyl ether, cyclopropyl glycidyl ether, cyclopentenyl glycidyl ether, cyclohexenyl glycidyl ether, tesyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, These include tridecyl glycidyl ether, tetradecyl glycidyl ether, pentadecyl glycidyl ether, hexadecyl glycidyl ether, heptadecyl glycidyl ether, octadecyl glycidyl ether, nonadecyl glycidyl ether, eicosyl glycidyl ether, and the like.

The monofunctional epoxyalkyl compound is preferably added in an amount of 0.001 to 0.1 mol per mol of the phenol.

If it is 0.1 or more, the crosslinking density during curing will be low (as well as the curing speed will be slow), and the heat resistance and mechanical strength of the molded product may deteriorate.

On the other hand, if it is less than o or ooi, there is a possibility that the effect will not be exhibited.

According to the method for producing a phenol resin according to the present invention, the extent to which the softening point is lowered can be adjusted by appropriately adjusting the amount of the monofunctional epoxyalkyl compound added within the above range.

When using the above monofunctional epoxyalkyl compound, a compound such as a tertiary amine, a quaternary ammonium salt, an imidazole derivative, etc. is added as a catalyst in an amount of 0.1 to
The reaction proceeds easily by adding at a ratio of 10%.

As the tertiary amine, dimethylaminobenzaldehyde,
Examples of quaternary ammonium salts include trinotyl ammonium iodide, trimethyl ammonium chloride, and trimethyl ammonium perchlorate, and imidazole derivatives include picrate and benzoate. ,
Nitroimidazole and the like are used.

In the practice of this invention, the use of catalysts such as the three amines described above is not essential.

However, when a catalyst such as a tertiary amine is not used, it is preferable to raise the reaction temperature or lengthen the reaction time.

Next, a method for producing a phenol resin according to the present invention will be specifically explained.

Phenols and aldehydes are charged in a predetermined molar ratio, an acid catalyst is added, and the mixture is heated and stirred while refluxing.

The liquid temperature is maintained at around 100° C. for several hours after the start of reflux (addition condensation process).

Thereafter, in order to separate condensed water from the resin, dehydration is performed by heating and stirring (dehydration process).

The method used up until now is the same as the production method for novolac type phenol resins that has been generally used.

Then, a monofunctional epoxyalkyl compound is added, if necessary, along with a catalyst such as a tertiary amine compound, a quaternary ammonium salt, or an imidazole derivative, for further reaction.

The objects of the present invention can be achieved no matter when the monofunctional epoxyalkyl compound or the catalyst is added during the addition condensation process, during the dehydration process, or at any time after the completion of the dehydration.

In the method for producing a phenol resin according to the present invention, the reason why the softening point of the phenol resin is lowered by the addition reaction of a monofunctional epoxyalkyl compound is that the epoxy ring of the added monofunctional epoxyalkyl compound opens and reacts with the OH group of the phenol. This is thought to be due to the fact that hydrogen bonds between OH groups are reduced or eliminated.

By carrying out the above method of the present invention, the softening point can be effectively lowered without deteriorating the properties of the molded product such as heat resistance, mechanical strength, and dimensional stability, and without generating gas during molding. Therefore, it is possible to eliminate deterioration in roll kneading workability and fluidity caused by a high softening point.

Next, examples of the present invention will be described together with comparative examples.

Example 1 Phenol 94P, 37% Formalin 70 and 1%
1 ml of HCI was placed in a reaction apparatus equipped with a stirrer, a thermometer, and a cooling reflux tube, and the mixture was heated and reacted with stirring. After reflux was started, the reaction was continued for 2 hours.

Next, a dehydrator was attached to the reaction apparatus and dehydration was carried out under reduced pressure, and dehydration and concentration was continued until the final temperature reached 150°C.

After reaching 150°C, keep the temperature at that temperature for 30 minutes, then return to normal pressure, add 5 g of butyl glycidyl ether, and keep at 150°C for 100 minutes.

As a result, 100 g of white solid resin was obtained.

Its softening point was 95°C and heat distortion temperature was 150°C.

Example 2 The steps up to the vacuum dehydration step were carried out in the same manner as in Example 1, and then 3 g of butyl glycidyl ether and 1.62 g of dimethylaminobenzaldehyde were added and kept at a constant temperature of 130° C. for 60 minutes.

The resulting white solid resin had a softening point of 96°C and a heat distortion temperature of 150°C.

Example 3 Cl2-Cl3 instead of 5g of butyl glycidyl ether
Mixed glycidyl ether (C12:55%, C13:4
Example 1 except that 5%) 151 was used (the softening point of the white solid resin obtained in the same manner was 98°C, and the heat distortion temperature was 15%).
It was 0°C.

Example 4 Same as Example 2 except that 2-methyloctyl glycidyl ether 101 was used instead of 5g of butyl glycidyl ether (the softening point of the white solid resin obtained in the same manner was 100°C, and the heat distortion temperature was 150°C)
Met.

Example 5 The softening point of a white solid resin obtained in the same manner as in Example 1 except that the amount of butyl glycidyl ether was changed to 101 was 93°C.
, the heat distortion temperature was 150°C.

Comparative Example Phenol 94P, 37% Formalin 70g and 1%
11 ml of HC was put into a reaction apparatus equipped with a stirrer, a thermometer, and a cooling reflux tube, and the reaction was carried out while being heated and stirred. After starting reflux, the reaction was continued for 2 hours.

Next, a dehydrator was attached to the above reactor to perform dehydration under reduced pressure, and dehydration and concentration was continued at a gate where the final temperature reached 150°C.

After reaching 150°C, the temperature was maintained for 30 minutes, and then the temperature was lowered.

The softening point of the resulting white solid resin is 120°C1
The heat distortion temperature was 150°C.

In addition, throughout the above-mentioned Examples and Comparative Examples, the heat distortion temperature was measured according to the method specified by ASTM.

Claims (1)

[Claims] 1. After reacting phenols and aldehydes under an acid catalyst, a monofunctional epoxyalkyl compound is added in an amount of o, ooi to 0.1 mole per mole of phenol. A method for producing a phenol resin, characterized in that the softening point of the phenol resin is adjusted by reaction. 2 When reacting a monofunctional epoxyalkyl compound,
2. The method for producing a phenolic resin according to claim 1, wherein any one of a tertiary amine, a quaternary ammonium salt, or an imidazole derivative is used as a catalyst.