JP2008007650A - Method for producing phenol resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a novolak type phenol resin having a narrow molecular weight distribution with slight unreacted phenols in high yield. <P>SOLUTION: The method for producing the novolak type phenol resin comprises reacting a phenol compound with an aldehyde compound using a silica catalyst supporting aluminum. Thereby, the novolak type phenol resin having ≥1.0 to ≤3.0 molecular weight distribution can be produced by the method for producing the novolak type phenol resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a phenol 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 addition, the conventional novolac type phenolic resin has a broad molecular weight distribution, the viscosity at the time of melting becomes high, and when such novolac type phenolic resin is used as a molding material, it is considered that the moldability is affected. In order to obtain a molding material having a higher degree of moldability, a material having a narrower molecular weight distribution width has been demanded.

  In the production of borac-type phenolic resins, the molecular weight is generally adjusted by adjusting the charged molar ratio of the phenolic compound and the aldehyde compound. Then, the amount of unreacted phenol tends to increase, and the molecular weight distribution tends to widen. As a general means for narrowing the molecular weight distribution, there is a method (for example, see Patent Document 1) of reducing the 1,2 nuclei of a phenol compound as a raw material by producing by a steam distillation method. There was a problem that would decrease. In general, the molecular weight distribution became wider as the reaction proceeded and the yield increased.

Japanese Patent Application Laid-Open No. 07-179545

  The present invention provides a method for producing a novolak-type phenol resin having a low content of unreacted phenol and a narrow molecular weight distribution in a shorter time and with a higher yield.

The present invention is achieved by (1) to (3).
(1) A method for producing a novolak-type phenol resin, in which a phenol compound and an aldehyde compound are reacted using a silica catalyst in which aluminum is supported.
(2) The said silica catalyst is a manufacturing method of the novolak-type phenol resin as described in (1) which is what carried | supported aluminum on the silica using the aluminum containing salt by the ion exchange method.
(3) The method for producing a novolac type phenol resin according to (1) or (2), wherein the molecular weight distribution of the novolac type phenol resin obtained by the method for producing the novolak type phenol resin is 1.0 or more and 3.0 or less.

  By the method of the present invention, it is possible to produce a novolak-type phenol resin with a small content of unreacted phenol and a narrow molecular weight distribution in a shorter time and with a higher yield.

  The present invention is a method for producing a novolac-type phenol resin, in which a phenol compound and an aldehyde compound are reacted using a silica catalyst in which aluminum is supported. Thereby, the novolak-type phenol resin with little unreacted content of the phenol compound used for manufacture of resin and narrow molecular weight distribution can be manufactured with high yield.

  The phenolic compound used in the present invention is not particularly limited as long as it can be used for the production of a novolak type phenolic resin. Preferably, phenol, orthocresol, metacresol, paracresol, xylenol, para Examples thereof include at least one phenol compound selected from tertiary butylphenol, paraoctylphenol, paraphenylphenol, bisphenol A, bisphenol F, resorcin, and the like.

  The aldehyde compound used in the present invention is not particularly limited as long as it can be used for the production of a novolak type phenol resin, but preferably formaldehyde, formalin, acetaldehyde, butyraldehyde, paraformaldehyde, acrolein, etc. Further, a mixture thereof can be mentioned, and a substance that is a source of generation of these aldehyde compounds can also be used.

  In the production method of the present invention, the reaction molar ratio between the phenol compound and the aldehyde compound is such that the aldehyde compound has a preferable lower limit of 0.1 mol and more preferably a lower limit with respect to 1.0 mol of the phenol compound. Is 0.5 mol, a preferable upper limit is 3.0 mol, and a more preferable upper limit is 1.0 mol.

As the silica catalyst in which aluminum is supported in the present invention, a silica having a tetrahedral structure centered on silicon and using aluminum supported thereon can be used as a carrier.
Examples of the method of supporting the aluminum on silica include a method of supporting the aluminum by using an impregnation method or an ion exchange method using a salt containing aluminum. For example, in an ion exchange method or the like, a solution containing the aluminum-containing salt is used, and the solution is passed through a column filled with the silica, or the silica is dispersed and mixed in the solution to obtain aluminum. Can be supported. Further, in order to increase the acidity, ion exchange may be performed using an acid. Examples of the aluminum-containing salt include aluminum nitrate and aluminum sulfate.

  The silica catalyst thus obtained is different from untreated simple silica or alumina, in which a part of the silicon in the silica is replaced with aluminum, so that the silica carrying aluminum has a negative charge. Since the acid point is expressed, the catalyst is preferable. In addition, the reaction can be further promoted and the reaction time can be shortened.

In the silica catalyst, transition metals of the fourth and fifth periods, tin, and magnesium can be used as metals other than aluminum in the periodic table.
In the silica catalyst, the preferable aluminum loading is preferably 0.02 mol, more preferably 0.1 mol, and a preferable upper limit of 0.7 mol with respect to 1 mol of silicon in silica. A more preferred upper limit is 0.5 mol. If it is more than the said lower limit, the acid intensity | strength as a catalyst is enough and reaction is accelerated | stimulated more.

  The particle diameter of the silica is not particularly limited, and a silica having a diameter of about 10 μm to 4 mm can be used. A smaller one has a larger surface area and a faster reaction. The silica may have fine pores such as micropores, mesopores, and macropores inside. The value of the specific surface area is not particularly limited, but in general, the larger the value, the faster the reaction.

  The amount of the silica catalyst used in the method for producing the novolak type phenolic resin of the present invention is preferably 15 to 50 wt%, more preferably 20 to 40 wt%, based on the charged weight of the phenol compound. When the amount used is larger than the lower limit, the molecular weight distribution is more effectively narrowed and the reaction is quicker. On the other hand, when the amount is less than the upper limit, it is possible to reduce the possibility that the effective amount used for the reaction of the phenol compound is adsorbed on the silica catalyst and affects the liquid phase reaction.

As a method for producing the novolak type phenolic resin of the present invention, it can be produced by a batch method using a general reaction kettle, and a predetermined amount of the phenol compound, the aldehyde compound and the silica catalyst are added to the reaction kettle. The novolac type phenol resin can be produced by reacting by stirring and mixing. More specifically, there may be mentioned a method in which the phenol compound and the silica catalyst are put into a reaction kettle and mixed, and then the aldehyde compound is added and mixed.
Although it does not specifically limit as reaction temperature in the manufacturing method of the said novolak-type phenol resin, Preferably it is 10 to 300 degreeC, More preferably, it is the range of 30 to 300 degreeC. Although it can be produced outside the above range, if it is lower than the lower limit, the reaction rate is lowered, the reaction time becomes too long to achieve a high conversion rate, and the productivity of the novolak type phenol resin may be lowered. On the other hand, if it is higher than the upper limit, side reactions and the like may proceed and the amount of by-products may increase.
The reaction time is not particularly limited, but is usually about 0.01 to 30 hours, preferably 0.05 to 20 hours.
The reaction pressure can be any of reduced pressure, increased pressure and normal pressure. From the viewpoint of reaction efficiency, the preferred operating pressure range is usually from 0.1 atm to 200 atm, more preferably from 0.5 atm to 100 atm.
After completion of the reaction, the used silica catalyst can be separated by a filtration method or the like, but can be used as it is as a filler such as a molding material without being separated.

  In the production method of the novolac type phenol resin of the present invention, a semibatch type or continuous flow type production method can be used in addition to the batch type. In the continuous flow type, a reactor packed with the silica catalyst by various methods such as a fixed bed, a fluidized bed, a suspension bed, and a shelf fixed bed, and the phenol compound and the aldehyde compound are used. And a liquid phase reaction can be carried out. At this time, as the silica catalyst to be packed, in the case of the fixed bed reactor, it is usually preferable to use a spherical or cylindrical molded one, and the representative length of the molded silica catalyst is 1 mm to 10 mm. It is better to mold it. In the suspension bed reactor, it is usually preferable to use a powder of 16 mesh to 400 mesh as the size of the silica catalyst. Also in the flow-type reaction, the reaction can be performed under the same reaction conditions as described above and by adjusting the residence time or the contact time with the silica catalyst as the reaction time.

  According to the method for producing a novolak-type phenol resin of the present invention, a novolak-type phenol resin having a small content of unreacted phenol and a narrow molecular weight distribution can be obtained. The molecular weight distribution is 1.0 or more. 3.0 or less can be obtained. The molecular weight distribution can be determined by analyzing the obtained resin by gel permeation chromatography (GPC) and converting to polystyrene.

  When the novolac type phenol resin obtained by the method for producing the novolak type phenol resin of the present invention is used as a molding material, the moldability is improved, and the strength of the molded product obtained thereby is improved. Such a novolac type phenol resin can be suitably used as a binder for a friction material, a grindstone, a sealing material and the like in addition to the molding material.

  Hereinafter, the content of the present invention will be described in more detail by way of examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

Example of production of silica catalyst (Production Example 1)
Under normal pressure, a solution obtained by dissolving 42 g of aluminum nitrate nonahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) in 500 ml of ion-exchanged water is added to 30 g of silica powder having a particle diameter of 75 to 150 μm in a reaction vessel, and the mixture is stirred for several minutes by a rotary evaporator. While impregnating, it was evaporated to dryness. Furthermore, after drying at 120 ° C. for 24 hours, it was fired at 500 ° C. for 5 hours under air flow. As a result, 31 g of a silica catalyst carrying 10 wt% Al was obtained.

(Production Examples 2 to 5)
In Production Example 1, the amounts of aluminum nitrate nonahydrate were 4.2 g, 21 g, 84 g, and 126 g, respectively, and the same as in Production Example 1 depending on the respective amounts of aluminum nitrate nonahydrate. A supported catalyst was produced in the same manner as in Production Example 1 except that the amount of ion-exchanged water was changed in proportion, and 1 wt%, 4.9 wt%, 20.3 wt%, and 29.9 wt% were supported, respectively. A silica catalyst was obtained.

(Example 1)
Under normal pressure, 30 g of the silica catalyst obtained in Production Example 1 is added to 79 g of phenol (manufactured by Wako Pure Chemicals, special grade) in a reaction vessel, the temperature is raised to 100 ° C., and 23 g of paraformaldehyde (92%, Sumitomo Corporation) is slowly added. And added. After stirring for 2 hours, 84 g of a reaction product containing a novolac type phenol resin was obtained. The reaction product obtained above was evaluated by gel permeation chromatography (GPC). As a result, the unreacted phenol content was 3.5%, the number average molecular weight Mn in terms of polystyrene was 833, and the molecular weight distribution Mw / Mn was 2.33.

(Examples 2 to 5)
In Example 1, in place of 30 g of the silica catalyst obtained in Production Example 1, each of the silica catalysts obtained in Production Examples 2 to 5 was used in the same manner as in Example 1 except that the same amount was used. Type phenolic resin was produced and evaluated.

(Comparative Example 1)
Under normal pressure, 30 g of CARiACT Q10 (Fuji Silysia) is added to 79 g of phenol (made by Wako Pure Chemicals, special grade) in a reaction vessel, the temperature is raised to 100 ° C., and 23 g of paraformaldehyde (92%, Sumitomo Corporation) is slowly added. It was. The mixture was stirred for 2 hours to obtain 82 g of a reaction product. The reaction product containing the novolak type phenol resin obtained above was evaluated by GPC. As a result, the unreacted phenol content was 86.2%, the number average molecular weight Mn in terms of polystyrene was 114, and the molecular weight distribution Mw / Mn. Was 1.08.

(Comparative Example 2)
Under normal pressure, 0.79 g of oxalic acid (manufactured by Wako Pure Chemical Industries, Ltd.) is added to 79 g of phenol (manufactured by Wako Pure Chemical Industries, Ltd.) in a reaction vessel, heated to 100 ° C., and 23 g of paraformaldehyde (92%, Sumitomo Corporation) is added. Slowly added. After stirring for 2 hours, 79 g of a reaction product containing a novolac type phenol resin was obtained. When the reaction product obtained above was evaluated by GPC, the unreacted phenol content was 25.8%, the number average molecular weight Mn227, and the molecular weight distribution Mw / Mn = 1.87.

(Comparative Example 3)
Under normal pressure, 23 g of paraformaldehyde (purity 92%, Sumitomo Corporation) and 0.03 g of aluminum powder with a particle size of 75 to 150 μm are added to 79 g of phenol (made by Wako Pure Chemicals, special grade) in a reaction vessel, and the temperature is raised to 100 ° C. The mixture was stirred for 48 hours to obtain 80 g of a reaction product containing a novolac type phenol resin. The reaction product obtained above was evaluated by GPC. As a result, the unreacted phenol content was 80.4%, the number average molecular weight in terms of polystyrene was Mn139, and the molecular weight distribution Mw / Mn was 1.23. .

(Comparative Example 4)
Under normal pressure, 23 g of paraformaldehyde (purity 92%, Sumitomo Corporation) and 30 g of alumina having a particle size of 75 to 150 μm are added to 79 g of phenol (made by Wako Pure Chemicals, special grade) in a reaction vessel, and the temperature is raised to 100 ° C. The mixture was stirred for a time to obtain 84 g of a reaction product containing a novolac type phenol resin. The reaction product obtained above was evaluated by GPC. As a result, the unreacted phenol content was 60.9%, the number average molecular weight Mn in terms of polystyrene was 181 and the molecular weight distribution Mw / Mn was 1.77. It was.

The results of Examples 1 to 5 and Comparative Examples 1 to 4 are summarized in Table 1.

  As is apparent from the results in Table 1, according to the present invention, the reaction product was faster than the comparative example, and even in a short time, the reaction product obtained had a reduced unreacted phenol content, The yield was improved and the molecular weight distribution was narrow.

  According to the present invention, it is possible to obtain a novolac type phenolic resin with a small amount of unreacted phenolic compound and a narrow molecular weight distribution, and the obtained novolac type phenolic resin includes, for example, a molding material, a friction material, a grindstone, and a sealing material. Etc. are suitably used as a binder.

Claims (3)

  A method for producing a novolac-type phenol resin, in which a phenol compound and an aldehyde compound are reacted using a silica catalyst in which aluminum is supported.   The method for producing a novolac type phenolic resin according to claim 1, wherein the silica catalyst is obtained by supporting aluminum on silica using an aluminum-containing salt by an ion exchange method.   The method for producing a novolac type phenol resin according to claim 1 or 2, wherein the molecular weight distribution of the novolac type phenol resin obtained by the method for producing the novolak type phenol resin is 1.0 or more and 3.0 or less.