JP5255810B2 - Method for producing dicyclopentadiene-modified phenolic resin - Google Patents

Description

  The present invention relates to a method for producing a phenol resin by reacting a phenol with dicyclopentadiene.

  Phenol resins obtained by reacting phenols with dicyclopentadiene (hereinafter also referred to as dicyclopentadiene-modified phenol resins or modified phenol resins) are useful as raw materials for epoxy resins with excellent flowability and moisture absorption. An epoxy resin obtained by epoxidizing the phenol resin is used as a material for a semiconductor encapsulant or a laminate for a printed wiring board.

The dicyclopentadiene-modified phenol resin is produced by heating phenols and dicyclopentadiene (hereinafter also referred to as DCPDs) together with an acid catalyst. Examples of the acid catalyst include boron trifluoride, boron trifluoride / phenol complex, and boron trifluoride / ether complex. After completion of the reaction, the acid catalyst is neutralized and deactivated using an alkaline catalyst neutralizing agent. This is to prevent the reaction from proceeding excessively in the subsequent step of distilling off unreacted phenol when the acid catalyst remains even after the reaction is completed.
The reaction product liquid after neutralizing the acid catalyst is separated into a solid containing a neutralizing agent and an acid catalyst residue, and a filtrate containing unreacted phenols and dicyclopentadiene-modified phenol resin. The filtrate is distilled under reduced pressure to remove unreacted phenols and collect dicyclopentadiene-modified phenolic resin.

  When dicyclopentadiene-modified phenolic resin is used as a material for semiconductor encapsulants or laminates, it may reduce electrical insulation, etc. It is necessary to sufficiently remove the phenols and impurities. In particular, the boron compound or fluorine compound derived from the acid catalyst is preferably 25 ppm or less, more preferably 22 ppm or less. However, since some boron compounds and fluorine compounds are dissolved in phenols, there is a problem that they remain in the reaction product liquid even after filtration.

  Conventionally, calcium carbonate or sodium hydroxide has been used as a catalyst neutralizing agent in the production of the modified phenolic resin. Such a catalyst neutralizing agent cannot adsorb boron compounds and fluorine compounds, and boron compounds and fluorine compounds are likely to remain in the reaction product solution. On the other hand, Patent Document 1 proposes using hydrotalcites as a catalyst neutralizing agent. Hydrotalcites have the effect of neutralizing the acid catalyst and adsorb boron compounds and fluorine compounds, so that impurities in the reaction product liquid can be reduced. However, in semiconductor encapsulants and printed circuit board laminates, further reductions in impurities are required, and neutralization of acid catalysts with hydrotalcites is still insufficient. There was a problem.

  In Patent Document 2, after neutralizing and deactivating the acid catalyst with an inorganic base such as calcium hydroxide, the resulting reaction product liquid contains adsorbed water, such as activated clay, acid clay, There has been proposed a method for obtaining a modified phenol resin containing less boron compound or fluorine compound by adding activated carbon or the like and hydrolyzing the complex formed by neutralization. However, this method has a problem that the adsorbed water in the powder is dissolved in unreacted phenol. For this reason, after completion | finish of reaction, a water | moisture content will be contained in the excess phenol distilled and collect | recovered from the modified phenol resin. As a result, when the modified phenol resin is produced using the recovered phenol, a part of the acid catalyst is deactivated by moisture, resulting in a decrease in reaction efficiency or a characteristic of the modified phenol resin. There is.

Japanese Patent No. 3028385 JP-A-11-199659

  An object of the present invention is to provide a method for producing a dicyclopentadiene-modified phenolic resin having a content of impurities that is small enough to be used as a raw material for a semiconductor encapsulant or a printed wiring board laminate.

The present invention is obtained by a reaction step (I) in which phenols and dicyclopentadiene are reacted in the presence of an acid catalyst as a reaction raw material to produce a dicyclopentadiene-modified phenol resin, and the reaction step (I). A method for producing a dicyclopentadiene-modified phenolic resin, characterized by comprising an acid catalyst deactivation step (II) for simultaneously adding an alkaline compound and zeolite to the reaction product solution to deactivate the acid catalyst. is there.

  The process for producing a dicyclopentadiene-modified phenolic resin of the present invention comprises removing the zeolite, acid catalyst and unreacted raw material from the reaction product obtained in the acid catalyst deactivation step (II), and dicyclopentadiene. It is preferable to have a resin recovery step (III) for obtaining a modified phenolic resin.

  According to the production method of the present invention, a dicyclopentadiene-modified phenolic resin having a softening point and an impurity content suitable for raw materials such as a semiconductor encapsulant and a printed wiring board laminate can be obtained. That is, the epoxidized modified phenolic resin produced by the method of the present invention has excellent electrical characteristics and is useful as a raw material for semiconductor encapsulants, printed wiring board laminates, and the like.

  Hereinafter, embodiments of the present invention will be described in detail. However, these are examples of the embodiments of the present invention, and needless to say, the present invention is not limited to these contents.

  The phenols used in the present invention are not particularly limited, but preferred examples include phenol, o-cresol, m-cresol, p-cresol, 2,6-xylenol, and mixtures thereof. Of these, phenol is preferable from the viewpoint of the characteristics and economical efficiency of the resin.

  The DCPDs used in the present invention are not particularly limited, but are preferably dicyclopentadiene (hereinafter also referred to as DCPD), dicyclopentadiene substituted with at least one alkyl group or vinyl group, or a mixture thereof. The alkyl group is a methyl group, an ethyl group or the like. Among these, it is preferable to use dicyclopentadiene because of the characteristics of the resin and availability.

  When phenols and DCPDs are reacted, the softening point of the resulting modified phenolic resin can be adjusted by adjusting the charged molar ratio (phenols / DCPDs). That is, when the feed molar ratio of phenols is increased, the softening point of the modified phenol resin is lowered, and when the feed mole ratio of phenols is decreased, the softening point of the modified phenol resin is raised. In order to produce a modified phenolic resin having an industrially significant softening point (70 to 150 ° C., preferably 80 to 140 ° C.), the preferable feed molar ratio is 1/1 to 15/1, more preferably 2/1 to 10/1.

Examples of the acid catalyst used for reacting phenols with DCPDs include boron trifluoride, boron trifluoride / phenol complex, boron trifluoride / ether complex, and the like. Among these, boron trifluoride / phenol complex is preferable because it is easy to handle and has a large yield of modified phenolic resin per unit amount of catalyst. In the case of boron trifluoride / phenol complex, the acid catalyst is used in an amount of 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, per 100 parts by mass of DCPDs.
The reaction temperature of phenols and DCPDs varies depending on the type of acid catalyst, but in the case of boron trifluoride / phenol complex, it is 20 to 170 ° C, preferably 50 to 150 ° C.
The reaction is preferably carried out with as little moisture as possible, preferably 100 ppm by mass or less.

  When the increase in viscosity of the reaction product stagnates, heating is stopped and the acid catalyst in the reaction product is deactivated. The acid catalyst is deactivated by adding an alkaline compound and zeolite to the reaction product, and heating and stirring at 10 to 150 ° C., preferably 30 to 90 ° C., for 10 minutes to 10 hours, preferably 20 minutes to 5 hours. Do. The addition of the alkaline compound and zeolite may be performed simultaneously or in separate steps. The end of the acid catalyst deactivation can be confirmed by, for example, dissolving in methyl isobutyl ketone, adding water to this solution and stirring, and measuring the pH of the aqueous layer.

Zeolite used in acid catalyst deactivation process, the main component is an alkali metal or alkaline earth metal _{aluminosilicates, M 2 / nO · Al 2} O 3 / xSiO 2 / yH 2 O (M in the formula is a metal Ion, n is a valence, and x and y are integers). For example, Na ₁₂ [(AlO ₂ ) ₁₂ (SiO ₂ ) ₁₂ ] · 27H ₂ O (4A type) or Na ₈₆ [(AlO ₂ ) ₈₆ (SiO ₂ ) ₁₀₆ ] · 276H ₂ O (13X type).
Zeolite adsorbs impurities such as acid catalyst residues, boron compounds, fluorine compounds, and alkali (earth) metals generated by neutralization of the acid catalyst, thereby improving the purity of the reaction product solution. Zeolite adsorbs these impurities well because zeolite has innumerable pores, and impurities that enter the pores are adsorbed on the inner walls of the pores.

The average pore diameter of the zeolite used in the acid catalyst deactivation step is not particularly limited, but is 1 to 20 mm (0.1 to 2 nm), preferably 5 to 15 mm (0.5 to 1.5 nm). It is preferable because of its excellent adsorption ability for fluorine compounds. The specific surface area of the zeolite is not particularly limited, 500~1500m ² / g, preferably from 700~1300m ² / g. The particle size and shape of the zeolite are not particularly limited, but the average particle size in the case of powder is 1 to 150 μm, preferably 5 to 100 μm, and the average particle size in the case of granular is 0.5 to 4 mm. preferable. If the particle size exceeds the upper limit value, the adsorptivity of the boron compound or the fluorine compound may be lowered, and if the particle size is smaller than the lower limit value, the filtration rate may be lowered, which is not preferable.

A powdery zeolite having an average particle size of 1 to 100 μm, preferably 10 to 50 μm, is preferred in terms of efficient adsorption of boron compounds and fluorine compounds and filterability. When the average particle size exceeds the upper limit, the adsorptivity of the boron compound or the fluorine compound may be lowered, and when the average particle size is smaller than the lower limit, the filtration rate may be lowered.
Zeolite is an adsorbent having pores inside. For example, the 4A type pore diameter is about 0.35 nm, and it can pass molecules having an effective diameter of 0.4 nm.
The amount of the zeolite used is 10 to 1000 parts by mass, preferably 50 to 500 parts by mass, per 100 parts by mass of the alkaline compound.

  The method for producing zeolite is not particularly limited, and examples thereof include a method for producing from a reagent and a method for producing from a natural mineral. As a method for producing from a reagent, a method using sodium silicate and sodium aluminate as starting materials is preferable. Examples of the method for producing from natural minerals include a method for producing from acid clay, kaolin, nacre, feldspar and the like. For example, a method of adding sodium hydroxide after baking kaolin mineral to metakaolin to increase reactivity, or a method of adding sodium hydroxide after grinding kaolin or volcanic glass to break the crystal structure, etc. It is done.

  The alkaline compound used in the acid catalyst deactivation step is not particularly limited, but sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonia and the like are preferable, and calcium hydroxide is particularly preferable. preferable. The addition amount of the alkaline compound is not particularly limited, but is 1 to 10 times by mass, preferably 2 to 5 times by mass with respect to 1 part by mass of the acid catalyst. If the addition amount of the alkaline compound exceeds the upper limit, the filtration time becomes too long, and the productivity of the modified phenolic resin decreases. Moreover, when the addition amount of the alkaline compound is less than the lower limit amount, there is a problem that the deactivation of the acid catalyst becomes insufficient.

  The reaction product in which the acid catalyst is deactivated is separated into a liquid and a solid content by solid-liquid separation means such as distillation and filtration, but filtration is simple and preferable. The filtration method and conditions are not particularly limited, but the filtration is preferably vacuum filtration or pressure filtration. The filtration temperature is room temperature to 150 ° C, preferably 70 to 130 ° C.

The filtration residue is a modified phenolic resin that is collected and used as a raw material for various applications. The recovered modified phenolic resin has a softening point of 70 to 150 ° C, preferably 80 to 140 ° C, PH of 5.0 to 9.0, preferably 6.0 to 8.0, boron compound and fluorine compound content. Are 25 ppm by mass or less, preferably 22 ppm by mass or less, and can be suitably used as a material for a semiconductor encapsulant, a laminate for a printed wiring board, or the like without any special treatment or purification.
The filtrate is distilled and unreacted phenol is recovered. The distillation can be performed under pressure, normal pressure, or reduced pressure, but vacuum distillation is preferred. The distillation temperature is 100 to 300 ° C, preferably 150 to 270 ° C, more preferably 170 to 250 ° C.
The recovered phenol has a purity of 90% by mass or more and can be reused for the production of the modified phenolic resin.

Hereinafter, the present invention will be described in more detail by way of examples.
In addition, about pH of the reaction product solution, about 0.5 g of the product solution was dissolved in 20 cm ³ of methyl isobutyl ketone, and 20 cm ³ of water was added and well stirred. After stirring, the mixture was allowed to stand for 30 minutes, and the pH of the aqueous layer was measured with a PH meter.
The softening point of the dicyclopentadiene-modified phenolic resin was measured using a ring and ball softening point measuring device (MEITECH, 25D5-ASP-MG type) in a glycerin bath at a heating rate of 5 ° C./min.
The content of the boron compound and fluorine compound in the dicyclopentadiene-modified phenolic resin was measured by an atomic absorption method using an atomic absorption apparatus [manufactured by Shimadzu Corporation, model number AA-6200].

Example 1
A reaction vessel (separable flask: 1 L) equipped with a stirrer, a thermometer, a reflux device, an inert gas introduction tube, and an oil bath was charged with 278 g (= 2.9 mol) of commercially available phenol and heated to 80 ° C. After the heating, 2.5 g of boron trifluoride / phenol complex was added, the temperature was further raised to 140 ° C., and 100 g (= 0.76 mol) of DCPD was gradually added over 2 hours to cause the reaction. After completion of the addition, 7.5 g of calcium hydroxide, zeolite [manufactured by Wako Pure Chemical Industries, Ltd., synthetic zeolite F9, powder, pore size 9 mm (9 nm), average particle size 7 μm (200 mesh passing product), specific surface area 1100 m ² / G] 2.5 g was added and stirred for 30 minutes to neutralize and deactivate the acid catalyst. After completion of the stirring, the reaction product solution was filtered. The filtrate was heated to 220 ° C. and distilled under reduced pressure, and 183 g of unreacted phenol was distilled off.
The yield of distillation residue (= modified phenolic resins) was 195 g. The softening point, pH, boron content and fluorine content of the modified phenolic resin were measured, and the results are shown in Table 1.

(Example 2)
In Example 1, Example 1 was repeated except that o-cresol was used instead of phenol. The softening point, pH, boron content and fluorine content of the obtained resin were measured, and the results are shown in Table 1.

(Example 3)
In Example 1, Example 1 was repeated except that 2,6-xylenol was used instead of phenol. The softening point, pH, boron content and fluorine content of the obtained resin were measured, and the results are shown in Table 1.

Example 4
In Example 1, instead of zeolite [manufactured by Wako Pure Chemical Industries, Ltd., synthetic zeolite F9, powder, pore size 9 mm (9 nm), average particle size 7 μm (200 mesh passing product), specific surface area 1100 m ² / g] Except for using ^2.5 g of zeolite [manufactured by Wako Pure Chemical Industries, Ltd., synthetic zeolite A3, powder, pore size 3 mm (3 nm), average particle size 7 μm (200 mesh passing product), specific surface area 1000 m ^{2 /} g] Example 1 was repeated. The softening point, pH, boron content and fluorine content of the modified phenolic resin were measured, and the results are shown in Table 1.

(Example 5)
In Example 1, Example 1 was repeated except that 7.5 g of sodium hydroxide was used instead of 7.5 g of calcium hydroxide. The softening point, pH, boron content and fluorine content of the modified phenolic resin were measured, and the results are shown in Table 1.

(Comparative Example 1)
In Example 1, Example 1 was repeated except that 10 g of calcium hydroxide was used instead of 7.5 g of calcium hydroxide and 2.5 g of zeolite. The softening point, pH, boron content and fluorine content of the modified phenolic resin were measured, and the results are shown in Table 1.

(Comparative Example 2)
In Example 1, Example 1 was repeated except that 10 g of hydrotalcite was used instead of 7.5 g of calcium hydroxide and 2.5 g of zeolite. The softening point, pH, boron content and fluorine content of the modified phenolic resin were measured, and the results are shown in Table 1.

(Comparative Example 3)
In Example 1, instead of 2.5 g of zeolite, 2.5 g of activated clay [manufactured by Toshin Kasei Co., Ltd., activated clay E, specific surface area of about 200 m ² / g, water content 5 mass%] was used. Example 1 was repeated. The softening point, pH, boron content and fluorine content of the modified phenolic resin were measured, and the results are shown in Table 1.

Claims (2)

Reaction step (I) in which phenols and dicyclopentadiene are reacted in the presence of an acid catalyst as a reaction raw material to produce a dicyclopentadiene-modified phenol resin, and a reaction product solution obtained in the reaction step (I) And a method for producing a dicyclopentadiene-modified phenolic resin characterized by having an acid catalyst deactivation step (II) in which an alkaline compound and zeolite are simultaneously added to deactivate the acid catalyst.   A resin recovery step (III) for obtaining dicyclopentadiene-modified phenolic resin by removing the zeolite, acid catalyst and unreacted raw material from the reaction product obtained in the acid catalyst deactivation step (II); The process for producing a dicyclopentadiene-modified phenolic resin according to claim 1.