JP2001106752A - Method for producing high ortho novolak resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novolak resin having a high ortho bond content at a short time by using an inexpensive catalyst. SOLUTION: This method for producing a high ortho novolak resin comprises using a mixed catalyst of an acidic catalyst selected from an organic acid, a divalent metal salt of the organic acid, or a mixture thereof, in combination with a basic catalyst selected from a metal oxide, a metal hydroxide or a mixture thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a high ortho novolak resin.

[0002]

2. Description of the Related Art It is generally known that a high ortho novolak resin has a higher curing speed than a normal novolak resin. For this reason, it has attracted industrial attention.

For the synthesis of this high ortho novolak resin, US Pat. No. 2,475,587 discloses a method using an oxide of a divalent metal, and US Pat.
No. 32,911 discloses a method using boric acid or a divalent metal borate. Also, U.S. Pat.
U.S. Pat. No. 4,113,700 discloses a method in which a divalent metal oxide, hydroxide or organic acid salt is used in combination with a divalent metal halide. A method is disclosed in which a metal oxide, hydroxide, or organic acid salt is used in combination with sulfonic acid or a salt thereof, or borofluoric acid or a salt thereof.

[0004]

However, when only a divalent metal oxide is used as a catalyst, the solubility in the reaction system is low, so that a long-time reaction is required at a low temperature and the ortho bond content is low. . To prevent this, it is necessary to use a large excess of phenol at high temperatures.

When boric acid or divalent metal borate is used, the amount of phenol used is reduced, but the reaction time is long, and the ortho bond content and the yield are poor.

[0006] Further, when an oxide or hydroxide of a divalent metal, an organic acid salt or a halide is used in combination, the ortho bond content is reduced.

Further, when a divalent metal oxide or the like is used in combination with a sulfonic acid salt or the like, the sulfonic acid salt as a catalyst is expensive, and an organic solvent such as benzene is used. With rising and environmental pollution problems.

Further, all of the above-mentioned methods have a problem that the reaction step is lengthened because a reflux step is required in the reaction.

Accordingly, an object of the present invention is to obtain a novolak resin having a high ortho bond content in a short time by using an inexpensive catalyst.

[0010]

The present invention provides an acidic catalyst selected from an organic acid or a divalent metal salt of an organic acid or a mixture thereof, and a metal oxide or a metal hydroxide or a mixture thereof. The above problem was solved by performing the reaction using a mixed catalyst obtained by combining a basic catalyst.

Since a predetermined catalyst is used, a high ortho novolak resin having an ortho bond content of 80% or more can be synthesized in a short time.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

The high ortho novolak resin according to the present invention is produced by reacting a phenol with formaldehyde using a predetermined catalyst.

The above-mentioned predetermined catalyst comprises a mixed catalyst obtained by combining an acidic catalyst and a basic catalyst.

The acidic catalyst is a catalyst selected from an organic acid or a divalent metal salt of an organic acid or a mixture thereof, and the basic catalyst is a metal oxide, a metal hydroxide or a mixture thereof. Catalyst.

Examples of the organic acid include acetic acid, formic acid, benzoic acid, lactic acid, oxalic acid and the like. In addition, organic acid 2
The salts of the multivalent metal salt include Zn ²⁺ , Mn ²⁺ , Ca ²⁺ , M
Examples of the above-mentioned organic acid salts of g ²⁺ , Ba ²⁺ , Cd ²⁺ , and Pb ²⁺ can be given.

The metal oxides or metal hydroxides include Zn ²⁺ , Mn ²⁺ , Ca ²⁺ , Mg ²⁺ , Ba ²⁺ , Cd
Oxides or hydroxides of ²⁺ and Pb ²⁺ .

The mixing ratio between the acidic catalyst and the basic catalyst is p
Depending on H, the ratio of acidic catalyst to basic catalyst is 10: 1 to 1
The ratio is 1: 1, preferably 5: 1 to 1.5: 1.

The amount of the mixed catalyst used is preferably 0.00001 to 0.1 mol, more preferably 0.003 to 0.01 mol, based on 1 mol of phenol, with respect to the total amount of the divalent metal.

Examples of the phenols include phenol and meta-substituted phenol substituted with a methyl group, an ethyl group, a phenyl group and the like. Examples of the formaldehyde include aliphatic aldehydes such as formalin, paraformaldehyde and acetaldehyde, aromatic aldehydes such as benzyl aldehyde, and cyclic aldehydes such as furfural.

The mixing amount of formaldehyde with respect to 1 mol of the phenol is preferably 0.5 to 1.0 mol.
0.7 to 0.9 mole is preferred. If the amount is less than 0.5 mol, the yield is low and the production cost is high, and if it is more than 1.0 mol, gelation is liable to occur.

The method for producing the high ortho novolak resin will be specifically described. First, a phenol and a formaldehyde are mixed at a predetermined ratio, and a predetermined amount of the mixed catalyst is added. The pH of the reaction system at this time is preferably 3 to 7, and a weak acidity of 5 to 6 is preferable. Then, immediately after heating, water in the reaction solution is distilled off, whereby the addition of formaldehyde to the phenol and the condensation reaction occur in parallel to produce a novolak resin. The distillation temperature at this time is preferably 100 to 180 ° C, and 100 to 14 ° C.
0 ° C. is preferred. If the temperature is lower than 100 ° C., water does not evaporate, and if the temperature is 180 ° C. or higher, the reaction rate increases and the ortho bond content increases, but the yield decreases.

By the above-mentioned distillation, water contained in the raw materials and water generated by the condensation reaction are distilled out of the reaction system. Since the addition and condensation reactions proceed simultaneously, the condensation reaction time is greatly reduced as compared with the case of reflux. Furthermore, the ortho-bond content of the obtained novolak resin is 80% or more,
It becomes a high ortho novolak resin.

The resulting high ortho novolak resin can be used as a molding powder, a coating, a binder for molding sand, and the like.

[0025]

Examples (Examples 1 to 10) Phenol (special grade, manufactured by Kanto Chemical Co., Ltd.) and formalin (special grade, manufactured by Nacalai Tesque, Inc., 37% aqueous solution) were mixed in the mixing ratio of phenol and formaldehyde shown in Table 1. Therefore, the reactor was charged. Then, the acidic catalyst and the basic catalyst described in Table 1 were used,
The proportions listed in Table 1 based on phenol were added to the reactor. Next, the mixture was heated to the temperature shown in Table 1 while stirring, and distillation was started. As the water was distilled off, the distillation temperature rose to about 130-140 ° C. After the end of the reaction time shown in Table 1, unreacted phenol was removed under reduced pressure at 80 ° C. and 3 mmHg or less. The obtained novolak resin was recovered, and the recovery rate was measured. The ortho-bond content of the novolak resin was measured by the following method.
Table 1 shows the results.

Measurement of Ortho Bond Content The ortho bond content was measured according to the method described in G. Casiraghi et al., Macromol. Chem., 182, 2151, 1981. That is, ¹³ CN
The MR was measured, and from the peak, the oo 'bond content, o
The -p 'binding content and pp' binding content were calculated. Then, the ortho bond content was calculated by the following equation. Ortho bond content (%) = [(oo ′ content) + 1/2 ×
(Op 'content)] / [(oo' content) + (op '
Content) + (pp ′ content)] × 100.

(Comparative Examples 1 to 6) The mixing ratio of phenol and formaldehyde shown in Table 1, the catalyst and its addition amount,
A novolak resin was recovered in the same manner as in Example 1, except that the reaction temperature and the reaction time were employed. Table 1 shows the results of the recovery rate and the ortho-bond content of the novolak resin.

In Table 1, the unit of the amount of catalyst used in Comparative Example 4 is shown by weight%.

[0029]

[Table 1]

Results As is apparent from Examples 1 to 10, all of the resulting novolak resins had an ortho bond content of 80% or more.

On the other hand, Comparative Examples 1 and 2 had a long reaction time. The ortho-bond content of the novolak resins obtained in Comparative Examples 1 to 5 was low at less than 80%.

Further, in Comparative Example 6, the reaction system exceeded pH 7 and gelled one hour after the reaction.

[0033]

According to the present invention, an inexpensive catalyst is used,
80% ortho-bond content in a short time without solvent
The above high ortho novolak resin can be synthesized.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4J033 CA01 CA02 CA03 CA04 CA05 CA11 CA12 CB03 CC04 CC06 CC09 CC12 HA12 HA21 HB01 HB05 HB08

Claims (2)

[Claims] An acidic catalyst selected from an organic acid or a divalent metal salt of an organic acid or a mixture thereof, and a mixed catalyst obtained by combining a basic catalyst selected from a metal oxide, a metal hydroxide or a mixture thereof. A method for producing a high ortho novolak resin having an ortho bond content of 80% or more using the method. 2. The metal salt of an organic acid is Zn ²⁺ , M
n ²⁺ , Ca ²⁺ , Mg ²⁺ , Ba ²⁺ , Cd ²⁺ , an organic acid salt of Pb ²⁺ , wherein the metal oxide or metal hydroxide is
Zn ²⁺ , Mn ²⁺ , Ca ²⁺ , Mg ²⁺ , Ba ²⁺ , Cd ²⁺ , P
The method for producing a high ortho novolak resin according to claim 1, which is an oxide or hydroxide of ^{b2 +} .