JPH07119268B2 - Method for producing novolac type phenolic resin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a novolac type phenolic resin having a monodisperse molecular structure, and the resin obtained by the present invention is used for molded articles and laminated. It can be used for known phenolic resins such as products, shell mold binders, retinoid grindstone binders friction material binders, epoxy raw materials for sealants, and epoxy resin curing agents.

[Conventional technology]

Usually, the novolac type phenol resin is obtained by reacting phenols and aldehydes in the presence of an acidic catalyst, but the binuclear amount is the initial charge molar ratio (ratio of aldehydes to phenols, hereinafter abbreviated as molar ratio). However, no matter how much the reaction proceeds, it does not decrease below a certain level.

When the molar ratio is increased, the binuclear amount is decreased, but on the contrary, the polymer region is increased, the softening point is increased, and there is a drawback that the fluidity of the compound is deteriorated. On the other hand, when the molar ratio is lowered, the polymer region is reduced, the softening point is lowered, and the fluidity of the compound is improved, but the amount of binuclear is large, and for example, the heat resistance of the molded product is lowered. There is.

As described above, in the known reaction method of novolac resin,
It has been impossible to obtain a novolac type phenolic resin having a small amount of both binuclear amount and high molecular weight region, that is, a so-called molecular structure is monodisperse.

As a method for producing a specific cyclic compound of P-alkylphenol, Japanese Patent Publication No. 60-33124, Japanese Patent Publication No. 60-33125, Japanese Patent Publication No. 60-33126 and the like are known, but all of them are limited to P-alkylphenol. Moreover, the process is complicated and not industrial.

Further, as a method for reducing the binuclear body, there is also a method of washing and fractionating a resin synthesized by a usual novolak reaction method using a difference in solubility with a specific solvent such as a mixed solvent of methanol and water. However, it is not practical because the process is complicated, the yield is poor, and the cost is increased.

[Problems to be solved by the invention]

From the above background, it has been desired to develop a monodisperse novolac type phenolic resin having good fluidity and exhibiting heat resistance. That is, it is a novolac type phenolic resin having a monodispersed molecular structure, which has a small polymer region, a small binuclear amount, and a narrow molecular weight distribution. As a result of earnest studies, the present inventors have found a method for producing a monodispersed novolac-type phenolic resin having excellent fluidity and heat resistance by reducing both the polymer region and the amount of binuclear body, which could not be produced conventionally. It was invented.

[Means for solving problems]

The present invention relates to a method for producing a novolac type phenolic resin having a monodisperse molecular structure which could not be produced conventionally, and as a result of earnest research, by first performing a resolization reaction and then performing a novolak reaction. ,
It is an invention of a method for producing a novolac type phenolic resin having a monodisperse molecular structure.

The present invention is a method of synthesizing a phenol and an aldehyde using a basic catalyst, and then synthesizing a novolak type phenol resin by adding a phenol and an acid catalyst, wherein the softening point of the novolak type phenol resin is 50 to 120.
℃ and GPC (Gell Permeation Chromatography
In the measurement by Toyo Soda Kogyo Co., Ltd., abbreviated as GPC hereinafter), the ratio of the peak height of the binuclear body to the peak height of the 7-nuclear body is 1.6 to 0.3, and the molecular structure is monodisperse. A method for producing a phenolic resin.

Examples of the phenols according to the present invention include phenol or alkylphenols such as cresol, xylenol, resorcinol, catechol, paratertiary butylphenol, octylphenol and phenylphenol, and mixtures thereof, and bisphenols such as bisphenol A, bisphenol F and bisphenol S. Aldehydes are formalin,
Paraformaldehyde, glyoxal, trioxane, polyoxane, etc., or a mixture or polymer thereof may be used.

As the basic catalyst, oxides and hydroxides of alkali metals such as sodium and potassium, and alkaline earth metals such as magnesium, calcium, and barium, and
Amino acids such as triethylamine and triethanolamine can be used.

As the acidic catalyst, inorganic acids such as hydrochloric acid and sulfuric acid, and
Organic acids such as oxalic acid and adibic acid can be used.

The molar ratio (formaldehydes / phenols) of the resolization reaction in the present invention is 0.5 to 3.0, more preferably 1.0 to 2.0. If the molar ratio is less than 0.5, the binuclear amount becomes too large, and if the molar ratio exceeds 3.0, the polymer region increases.

The molar ratio of the novolak reaction is 0.3 to 0.9, more preferably 0.55 to 0.75. If the molar ratio is less than 0.3, the binuclear amount becomes too large, and if it exceeds 0.9, the polymer region increases.

The novolak type phenol resin according to the present invention means that the phenols and the aldehydes are first subjected to the resolization reaction in the presence of a basic catalyst within the molar ratio range of the resolization reaction, and then the phenols are added to the novolak resin. The softening point is 50 to 120 among those synthesized by adding an acidic catalyst to cause a novolak reaction to be carried out within the molar ratio range of the reaction.
C., more preferably 80 to 105.degree. Softening point or 5
If the temperature is lower than 0 ° C, the product is hard to block and the workability is poor. If the temperature is higher than 120 ° C, the viscosity is too high and it is difficult to adapt to the manufacturing process.

The ratio of the peak height of the binuclear body to the peak height of the 7 nucleus body in the GPC measurement of the novolac type phenol resin in the present invention is 1.6 to 0.3. If it exceeds 1.6, there is a drawback that the amount of binuclear bodies is too large, the softening point is lowered, and the heat resistance of the molded article is lowered. If it is less than 0.3, the polymer region increases, the softening point increases, the fluidity of the molded product deteriorates, and the work efficiency decreases.

GPC measurement conditions Model: HLC-802UR manufactured by Toyo Soda Kogyo Co., Ltd. Column array: G3000HLX + G2000HLX x 2 Flow rate: 0.8 ml / min Oven bath temperature: 40 ° C Sample concentration: 150-200 mg / THF10 ml Detection method: RI (differential refractometer [Advantages of the Invention] According to the present invention, a monodisperse novolac type phenolic resin having excellent heat resistance and fluidity can be stably produced and can be widely supplied to various fields.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the examples. All "%" described here indicate "weight".

Example 1. Phenol 470 g (5 mol), 50% formalin 450 g (7.5
Mol) and 10 g of sodium hydroxide are placed in a reaction apparatus equipped with a thermometer, a reflux condenser, a stirrer and a dehydrator, and the temperature is gradually raised to 75 ° C. and the resolization reaction is carried out for 2 hours. 30
After cooling to below ℃, 611 g (6.5 mol) of phenol and 10
Add 91 g of% hydrochloric acid, bring the mixture to 95 to 100 ° C., and stir under reflux for 3 hours to cause novolak reaction. Immediately vacuum degree 680mmHg
The internal temperature was raised to 200 ° C., and the temperature was maintained for 2 hours for dehydration and demonomerization, and the product was taken out in a cooling vat to obtain the target resin. The softening point of this resin is 95.
The peak height of the binuclear body / the peak height of the 7-nuclear body in GPC measurement at 1.degree.

The GPC measurement of this resin is shown in Figure 2.

Example 2. Phenol 470 g (5 mol) and 50% formalin 210 g (3.5
Mol) and 30 g of oxalic acid using the same apparatus as in Example 1.
A novolak reaction was carried out under stirring and reflux at 5 to 100 ° C., followed by dehydration and demonomerization to obtain a resin. As for the characteristics of this resin, the softening point was 95 ° C., and the height ratio of the peak height of the binuclear body / the peak height of the binuclear body in GPC measurement was 1.74.

The GPC measurement of this resin is shown in Figure 1.

[Brief description of drawings]

 Figure 2 shows the GPC measurement results of the resin of the present invention. FIG. 1 shows the GPC measurement results of resins other than the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kunio Okamoto, 622, Oyagi-cho, Takasaki-shi, Gunma Gunei Chemical Industry Co., Ltd. (72) Masahiko Hatori, 622, Oyagi-machi, Takasaki-shi, Gunma Gunei Chemical Industry Co., Ltd. ( 56) References JP-A-62-212410 (JP, A) JP-B-47-13974 (JP, B1)

Claims (1)

[Claims] 1. Phenols and aldehydes are subjected to a resolization reaction with a basic catalyst at a molar ratio (formaldehyde / phenol) of 0.5 to 3.0, and then phenols are added to make the molar ratio of 0.3 to 0.9 and further acidic. In the method of synthesizing a novolak type phenolic resin by adding a catalyst to make it a novolak type, the softening point of the novolak type phenolic resin is
A method for producing a novolak-type phenol resin, wherein the ratio of the peak height of the binuclear body to the peak height of the 7-nuclear body in GPC measurement at 50 to 120 ° C. is 1.6 to 0.3.