JP2007100028A - Method for producing novolak-type phenol resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a novolak-type phenol resin, capable of easily removing a catalyst and scarcely containing the residual catalyst. <P>SOLUTION: This method for producing the novolak-type phenol resin comprises reacting aldehydes with phenols, wherein the aldehydes as an aqueous solution are brought into contact with a solid catalyst, so as to be activated. The method for producing the novolak-type phenol resin preferably uses one kind or not less than two kinds selected from a water-insoluble heteropolyphosphoric acid, montmorillonite, silica, and zeolite as the solid catalyst. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a novolac type phenolic resin.

  Novolac-type phenolic resin has good electrical properties and is also excellent in heat resistance and flame retardancy, so it is a raw material for epoxy resins for electrical and electronic materials and semiconductor encapsulants, and a curing agent for epoxy resins. Furthermore, it is widely used as a binder resin for laminates, molding materials and mold materials.

In general, novolac-type phenolic resins are obtained by reacting phenols and aldehydes with inorganic acids and organic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, phosphorous acid, oxalic acid and p-toluenesulfonic acid as catalysts. can get. In the phenol resin thus obtained, the above-mentioned inorganic acid and organic acid catalyst are present as impurities, and therefore a step of removing or neutralizing them is necessary. Moreover, even if these are removed or neutralized, it is difficult to completely remove them, which may affect the physical properties of the cured product (for example, see Patent Document 1).
JP 2001-64341 A

  An object of the present invention is to provide a method for producing a novolac-type phenolic resin in which catalyst removal is easy and there is almost no residual catalyst.

The present invention
(1) A method for producing a phenol resin by reacting an aldehyde with a phenol, wherein the aldehyde is made into an aqueous solution by being brought into contact with a solid catalyst to be activated. Method,
(2) The method for producing a novolak-type phenol resin according to item (1), wherein the solid catalyst is one or more selected from water-insoluble heteropolyacid, montmorillonite, silica and zeolite,
It is.

  By the method of the present invention, it is possible to produce a novolac-type phenol resin that is easy to remove the catalyst and has almost no residual catalyst.

  The present invention relates to a method for producing a novolac-type phenol resin by reacting an aldehyde with a phenol, wherein the aldehyde is activated by contacting with a solid catalyst as an aqueous solution. It is a manufacturing method of resin.

  The phenol used in the present invention is not particularly limited as long as it is a phenol compound used in the production of a novolak type phenol resin, but preferably phenol, orthocresol, metacresol, paracresol, xylenol, paratarsha It is at least one or more phenols selected from libutylphenol, paraoctylphenol, paraphenylphenol, bisphenol A, bisphenol F, resorcin, and the like.

  The aldehyde used in the present invention is not particularly limited as long as it is an aldehyde compound used in the production of a novolak type phenol resin, but is preferably formaldehyde, acetaldehyde, butyraldehyde, acrolein or the like or a mixture thereof. . In the present invention, the aldehydes are used as an aqueous solution, but a solvent other than water, such as alcohol, may be added as necessary as long as the reactivity is not impaired. The concentration when the aldehyde is used as an aqueous solution is preferably 1 to 99% by weight, more preferably 10 to 95% by weight.

In the present invention, when a phenol is used as the phenol and a formaldehyde aqueous solution (formalin) is used as the aqueous solution of the aldehyde, a so-called phenol novolak resin can be obtained.
In the present invention, the reaction molar ratio of phenols to aldehydes is preferably 0.1 to 3.0 moles, more preferably 0.5 to 1.0 moles relative to 1.0 mole of phenols. Is a mole.

The solid catalyst used in the present invention is not particularly limited as long as it is a so-called solid acid catalyst exhibiting solid acidity. Specific examples thereof include water-insoluble heteropolyacids, smectites such as montmorillonite, silica, zeolite, alumina, and ion exchange resins. Among these, water-insoluble heteropolyacid, montmorillonite, silica, and zeolite are preferable from the viewpoint of reactivity, versatility, shape, and cost.
These solid acid catalysts may be modified with metals, metal oxides, or the like, or may be partially replaced with constituent elements in order to further improve the activity of aldehydes. Some heteropolyacids are soluble in water. If these are used, it becomes difficult to separate the catalyst and the aldehyde aqueous solution, and therefore it is preferable to use a water-insoluble heteropolyacid.

In the method for producing a novolak type phenolic resin of the present invention, an aldehyde is made into an aqueous solution, activated by contact with a solid catalyst, and this is reacted with a phenol to produce a novolac type phenolic resin. Examples of the method for activating the aqueous solution of aldehydes by bringing them into contact with the solid catalyst include a method in which the catalyst is filled in an apparatus and the aqueous solution of the aldehydes is passed through it. As the apparatus and its filling method, various methods such as a fixed bed, a fluidized bed, a suspension bed, and a shelf fixed bed are adopted, and any method can be used.
For example, when a solid catalyst is packed in a fixed bed reactor, it is usually better to mold the solid catalyst into a spherical shape or a cylindrical shape, and typically the length is 1 mm to 10 mm. It is good.
In addition, the size of the catalyst when used in a suspension bed reactor is usually 16 mesh to 400 mesh powder. The amount of the solid catalyst to be used is usually 0.01 to 50% by weight as the solid catalyst concentration in the reactor containing the aqueous solution of the aldehydes and the solid catalyst in the suspension bed reactor, preferably Is 0.1 wt% to 30 wt%.

  Although it does not specifically limit as processing temperature when making the said aldehyde contact with a solid catalyst and it activates, Preferably it is 10 to 100 degreeC, More preferably, it is the range of 30 to 100 degreeC. If the temperature is lower than 10 ° C, the reaction rate for activation may decrease. In this case, a residence time (reaction time in the case of a batch system) is required to achieve a high conversion rate in the reaction of aldehydes and phenols. May become too large and productivity may decrease. On the other hand, if the temperature is higher than 100 ° C., the aqueous solution may boil and cannot be stably treated. The reaction time (in the flow reaction, the residence time or the catalyst contact time) is not particularly limited, but is usually 0.01 hours to 30 hours, preferably 0.05 hours to 20 hours.

  Next, as a method of reacting the activated aldehydes and phenols obtained as described above, any of batch, semi-batch and continuous flow methods can be carried out. When the reaction is carried out batchwise, an activated aqueous solution of aldehydes is added to a reaction kettle filled with phenols maintained at a predetermined temperature. At this time, the phenols and the aqueous solution of the activated aldehydes may be charged all at once. However, if an aqueous solution of aldehydes is added all at once, it may generate intense heat. Depending on the case, the reaction may be carried out by adding small amounts successively.

The temperature in the reaction between the activated aldehydes and phenols is not particularly limited, but is preferably in the range of 10 ° C to 300 ° C, more preferably 30 ° C to 300 ° C. If it is lower than 10 ° C., the reaction rate may be lowered. In this case, the reaction time becomes too long to achieve a high conversion rate, and the productivity of the phenol resin may be lowered. On the other hand, when the temperature is higher than 300 ° C., an undesirable side reaction or the like proceeds, which may affect the increase of by-products and the stability of the phenols and aldehydes as raw materials and the phenol resin as a product. There is.
The reaction time is not particularly limited, but is usually 0.01 hours to 30 hours, preferably 0.05 hours to 20 hours. The reaction pressure can be carried out at any of reduced pressure, increased pressure and normal pressure. From the viewpoint of reaction efficiency (reaction efficiency per unit volume), it is not preferable to carry out at a too low pressure. Usually, the preferred operating pressure range is 0.1 to 200 atmospheres, more preferably 0.5 to 100 atmospheres.

  In the method for producing a novolac type phenol resin of the present invention, the solid catalyst used for activating aldehydes can be used again and again. As the method, the solid catalyst recovered by separating the aqueous solution of the aldehyde after contacting with the aldehyde may be used as it is, but a part or all of the recovered solid catalyst may be subjected to heat treatment or the like. It can be regenerated and used by the method.

  EXAMPLES Hereinafter, although the content of this invention is demonstrated in detail by an Example, this invention is not limited to the following examples, unless the summary is exceeded.

<Example 1>
After stirring 700 g of 35% formaldehyde aqueous solution at 50 ° C., 100 g of heteropolyacid (tungstophosphoric acid partial cesium salt H0.5Cs2.5P12O40 (manufactured by Nippon Inorganic Chemical Industry Co., Ltd.)) was added. After stirring for 3 hours while maintaining at 50 ° C., the heteropolyacid was filtered off to obtain an activated aqueous formaldehyde solution.

In a 3 L three-necked flask, 1000 g of phenol was heated to 100 ° C. while stirring, 700 g of the resulting activated formaldehyde aqueous solution was sequentially added over 1 hour, and the mixture was reacted at reflux at 100 ° C. for 6 hours. . After completion of the reaction, the reaction solution was taken out after cooling to room temperature, and the obtained novolak type phenol resin was measured for the weight average molecular weight, number average molecular weight, molecular weight distribution, and free phenol amount by liquid chromatography.
In the measurement, liquid chromatography was performed using Tosoh GPC columns (G1000HXL: 1, G2000HXL: 2, G3000HXL: 1) under the analysis conditions of a flow rate of 1.0 ml / min, elution solvent tetrahydrofuran, and column temperature of 40 ° C. A differential refractometer was used as a detector.

<Examples 2 to 4>
In Example 1, instead of heteropolyacid, montmorillonite (Kunimine Kogyo Co., Ltd., Kunipia F), aluminum-substituted montmorillonite ion-exchanged with aluminum nitrate, zeolite (Wako Pure Chemical Industries, Ltd. NaY), spherical silica (Fuji Silysia Chemical) The reaction and evaluation were carried out in the same manner as in Example 1 using CARiACT Q-10) manufactured by the company as a solid catalyst.

<Comparative Example 1>
In Example 1, the reaction / evaluation was performed in the same manner as in Example 1 except that the reaction was performed using a normal aqueous formaldehyde solution instead of the aqueous formaldehyde solution activated with the heteropolyacid.

<Comparative example 2>
In a 3 L three-necked flask, 1000 g of phenol and 10 g of oxalic acid were heated to 100 ° C. while stirring, 700 g of an aqueous formaldehyde solution was sequentially added over 1 hour, and the reaction was performed while refluxing at 100 ° C. for 6 hours. After completion of the reaction, the reaction solution was taken out after cooling to room temperature, and the obtained novolak type phenol resin was measured for the weight average molecular weight, number average molecular weight, molecular weight distribution, and free phenol amount by liquid chromatography.

  The said Examples 1-4 and Comparative Examples 1-2 were put together in Table 1, and were shown.

  As is clear from the results in Table 1, the novolak type phenolic resin obtained in spite of the fact that no residual catalyst was observed in the examples had a high molecular weight, whereas the reaction according to Comparative Example 1 did not increase the molecular weight. It was not resinized. Further, in a general method of adding the oxalic acid catalyst according to Comparative Example 2 into the system, although the resin has a high molecular weight, the catalyst (oxalic acid) remains, and a step for removing this is necessary.

  According to the present invention, it is possible to obtain a novolac-type phenolic resin that is easy to remove the catalyst and has almost no residual catalyst, and the novolac-type phenolic resin obtained is, for example, a molding material, a friction material, a grindstone, a sealing material. Etc. are suitably used as a binder.

Claims (2)

  A process for producing a phenol resin by reacting an aldehyde with a phenol, wherein the aldehyde is activated by contacting with a solid catalyst as an aqueous solution.   The method for producing a novolak type phenol resin according to claim 1, wherein the solid catalyst is one or more selected from water-insoluble heteropolyacids, montmorillonite, silica and zeolite.