JP3238288B2 - Method for producing novolak type phenolic resin - Google Patents

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, which comprises reacting while inducing resin properties during the reaction in order to obtain a resin having a very narrow quality standard.

[0002]

2. Description of the Related Art Novolak-type phenolic resins are widely used in various fields in the industrial world because of their excellent properties such as heat resistance, abrasion resistance, mechanical strength, electrical insulation, low smoke generation and acid resistance. Have been. These novolak-type phenolic resins are produced by charging phenols, aldehydes, catalysts, and the like in a lump or dividedly, and thereafter controlling the heating temperature, the reaction temperature, the reaction time, the pressure, and the like to a constant value. . However, a novolak type phenol resin is an oligomer having a molecular weight distribution, and when produced by a general-purpose plant by the above method, there is a variation in characteristic values between production lots. For example, the solution viscosity in a 50% ethanol solution is reduced. For example, a variation of 5 to 30% with respect to the average value is obtained. Therefore, in applications where the variation cannot be tolerated due to practical characteristics, a plurality of lots having different resin characteristics are blended and used so as to have target characteristic values.

[0003] Therefore, there is a strong demand for a novolak-type phenolic resin that can be used alone in one lot without using a novolak-type phenolic resin and that has little variation in characteristic values between production lots. In order to respond to these demands in recent years, the introduction of high-precision weighing machines and metering pumps has led to the improvement of raw material charging accuracy, and the introduction of sequencers and computers has led to the production of novolak-type phenolic resins by finely controlling the reaction conditions. However, a method for producing a resin having a constant quality has not yet been developed.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to use a single novolak type phenolic resin in applications where a plurality of lots having different resin characteristics of the novolak type phenolic resin have been used together so as to meet required characteristics. An object of the present invention is to provide a method for producing a novolak-type phenol resin having a very narrow quality standard (target characteristic range) that can be realized.

[0005]

The present invention relates to a method for producing a novolak type phenol resin obtained by reacting a phenol with an aldehyde in the presence of an acidic catalyst.
During the condensation reaction, the resin properties are measured, and if the property value is larger than a predetermined target value, phenols are added, and if the property value is smaller, aldehydes are added, and the reaction is continued. The present invention relates to a method for producing a novolak-type phenol resin, which is characterized by inducing properties. Resin properties correlated with molecular weight in the present invention
Properties include melt viscosity, average molecular weight, melting point, softening point,
Liquid viscosity, refractive index, etc., but are not limited thereto.
Although it is not possible to measure in a short time with little measurement error
Is good. In the present invention, the solution viscosity means that the resin
The viscosity of a solution dissolved at a certain concentration in a medium, 50%
Often, ethanol solutions are measured.

The phenols used in the present invention include:
Phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, ethylphenol,
One or more selected from phenols such as alkylphenols and bisphenols can be used.
As the aldehyde, one or more aldehydes selected from formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde, salicylaldehyde and the like can be used. As the catalyst to be used, one or more selected from inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, organic acids such as oxalic acid and acetic acid, and organic acid salts of divalent metals such as lead, tin and zinc. Can be used in combination.

[0007] The target value of the resin properties during the condensation reaction is set by the correlation between the product properties and the property values of the sample during the reaction. Regarding the addition amount of phenols or aldehydes for deriving to the target characteristic range of the product when the target value of the resin properties during the condensation reaction deviates from the target value, even if the addition amount is changed depending on the fixed amount or the degree of departure. Preferably, it is preferable to perform a trial production experiment and obtain an estimation formula so that an appropriate addition amount can be added according to the degree of deviation of the resin characteristic from a target value. The location of measurement of the resin properties during the condensation reaction is not particularly limited, but is preferably during the reflux reaction.

[0008]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited by these examples.

Examples 1 to 7 A reactor equipped with a stirrer, a heat exchanger and a thermometer was charged with 1000 parts of phenol, 640 parts of 37% formalin and 10 parts of oxalic acid, and subjected to a reflux reaction under normal pressure for 3 hours. The viscosity of the contents was measured at 95 ° C. with a B-type viscometer. Here, if the measured viscosity value of the content was lower than the target value, formalin was added, if higher, phenol was added, and if it was within the target value, the reflux reaction was continued for 2 hours. Thereafter, a dehydration reaction is performed at normal pressure until the liquid temperature reaches 150 ° C., and further,
A novolak-type phenol resin was obtained by performing a dehydration-condensation reaction at 180 ° C. at a degree of vacuum of 60 Torr. Seven lots were produced by the above manufacturing method. Table 1 shows the viscosity target values and process inspection results of the sample during the reaction, the amount of phenol or formalin added when the target was not satisfied, and the solution viscosity measurement results of the obtained 50% ethanol solution of the novolak-type phenol resin. there were. In the table, σ is the standard deviation
Is shown.

<< Comparative Examples 1 to 7 >> 1000 parts of phenol and 37% formalin 640 were added to a reactor of the same type as in Example 1.
And 10 parts of oxalic acid, refluxed under normal pressure for 5 hours, then dehydrated at normal pressure until the liquid temperature reached 150 ° C, and further dehydrated and condensed to 180 ° C at a vacuum of 60 Torr. Then, a novolak type phenol resin was obtained.
Seven lots were produced by the above manufacturing method. The results of measuring the solution viscosity of a 50% ethanol solution of the obtained novolak type phenol resin are as shown in Table 1.

[0011]

[Table 1]

<< Examples 8 to 14 >> In a reactor of the same type as in Example 1, 1000 parts of cresol was added.
570 parts of 37% formalin and 2.5 parts of 30% hydrochloric acid were charged and refluxed at normal pressure for 5 hours, and the weight average molecular weight (Mw) of the content was measured by a gel permeation chromatography method. Here, if the weight average molecular weight of the content was lower than the target value, formalin was added, and if it was higher, cresol was added. If the weight average molecular weight was within the target value, the reflux reaction was continued for 2 hours. Thereafter, a dehydration reaction is carried out at normal pressure until the liquid temperature reaches 140 ° C.
A novolak-type cresol resin was obtained by performing a dehydration condensation reaction to 0 ° C. Seven lots were produced by the above manufacturing method. The target value of the weight average molecular weight of the sample during the reaction, the result of the process inspection, the addition amount of cresol or formalin when the target was not satisfied, and the measurement result of the weight average molecular weight of the novolak cresol resin were as shown in Table 2. In the table, σ indicates a standard deviation.

Comparative Examples 8 to 14 In a reactor of the same type as in Example 1, 1000 parts of cresol and 570 of 37% formalin were added.
And 2.5 parts of 30% hydrochloric acid, refluxed under normal pressure for 7 hours, then dehydrated at normal pressure until the liquid temperature reaches 140 ° C., and further heated to 160 ° C. at a vacuum of 80 Torr.
A novolak-type cresol resin was obtained by performing a dehydration condensation reaction until this. Seven lots were produced by the above manufacturing method. The measurement results of the weight average molecular weight of the obtained novolak cresol resin are as shown in Table 2.

[0014]

[Table 2]

The novolak type phenolic resins according to Examples 1 to 7 and 8 to 14 are comparative examples 1 to 7 and 8 to 14
The variation between lots is extremely small as compared with the novolak-type phenol resin.

[0016]

According to the production method of the present invention, it is possible to obtain a novolak-type phenol resin having a very small variation between production lots. Therefore, if the method for producing a novolak phenolic resin according to the present invention is used, a resin having an extremely narrow quality standard can be stably produced.

Continuation of front page (56) References JP-A-6-322054 (JP, A) JP-A-3-152460 (JP, A) JP-A-55-104322 (JP, A) JP-A-4-76023 (JP) JP-A-4-88001 (JP, A) JP-A-60-92315 (JP, A) JP-A-57-202121 (JP, U) East German Economic Patent No. 219870 (58) Field (Int.Cl. ⁷ , DB name) C08G 8/00-8/38 C08G 85/00 G01N 1/00-1/34 G01N 25/00-25/72 G01N 30/00-30/96 G01N 33 / 44 G05D 21/00-21/02 G05D 24/00-24/02 WPI / L (QUESTEL) JICST file (JOIS)

Claims (2)

(57) [Claims] In a method for producing a novolak-type phenol resin obtained by reacting a phenol and an aldehyde in the presence of an acidic catalyst, a resin property correlated with a molecular weight is measured during the condensation reaction, and the characteristic value is measured. Novolak type phenolic resin is characterized by adding phenols if it is larger than the predetermined target value, and adding aldehydes if it is smaller than the predetermined value and continuing the reaction to induce the target properties. Production method. 2. The novolak type according to claim 1, wherein the resin properties correlated with the molecular weight measured during the condensation reaction are melt viscosity , average molecular weight determined by gel permeation chromatography, melting point, softening point, solution viscosity, and refractive index. Method for producing phenolic resin.