JP2008231374A - Method of manufacturing phenol-modified aromatic hydrocarbon formaldehyde resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phenol-modified aromatic hydrocarbon formaldehyde resin excellent in moisture resistance and the adhesiveness with a metal. <P>SOLUTION: A method of manufacturing the phenol-modified aromatic hydrocarbon formaldehyde resin comprises subjecting an aromatic hydrocarbon formaldehyde resin having a mean number of reacted protons in an aromatic ring of 1.8-3.0 and an acetal value of 0-2.2 mol/kg, and phenol or a phenol derivative, to a condensation reaction in the presence of an acid catalyst. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

The present invention relates to a method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin excellent in moisture resistance and metal adhesion, and the phenol-modified aromatic hydrocarbon formaldehyde resin obtained in the present invention is a molding material, epoxy resin Used for raw materials, epoxy curing agents, etc.

Phenol-modified aromatic hydrocarbon formaldehyde resins are already known, and this modified resin requires more moisture resistance and electrical properties than general-purpose phenolic resins. Laminates for electrical and electronic parts, molded products, coating materials, sealing materials, etc. Used as a thermosetting resin. A phenol novolac resin is widely used as a sealing resin for semiconductor devices. In recent years, packages have become smaller and thinner due to high-density mounting of electronic devices, and since they are exposed to higher temperatures than ever before, the problem of package cracking has occurred and crack resistance has been required. As a solution, it is necessary to reduce the hygroscopicity of the cured product and improve the adhesive strength with the metal part, and a method of introducing a structure that exhibits low hygroscopicity to epoxy resin and phenol resin curing agent is known and biphenyl type Use of an epoxy resin, a phenol aralkyl resin, a phenol-modified aromatic hydrocarbon formaldehyde resin or the like has been studied. (See Patent Documents 1, 2, and 3)
JP-A 61-47725 JP 59-105018 JP-A-10-279666

  However, since the moisture absorption required for the sealing resin of the semiconductor device and the adhesive strength with the metal part are increasing year by year, it cannot be said that all of them show satisfactory performance.

  An object of the present invention is to provide a phenol-modified aromatic hydrocarbon formaldehyde resin excellent in moisture resistance and adhesion to a metal.

As a result of intensive studies, the present inventors have found that the aromatic hydrocarbon formaldehyde resin used as a raw material for obtaining a phenol-modified aromatic hydrocarbon formaldehyde resin excellent in moisture resistance and adhesion to metal has a number of proton reactions in the aromatic ring. And a specific range for the acetal number was found to be required.
That is, the present invention condenses an aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in an aromatic ring of 1.8 to 3.0 and an acetal value of 0 to 2.2 mol / Kg with phenols in the presence of an acidic catalyst. The present invention relates to a method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin characterized by reacting.

The phenol-modified aromatic hydrocarbon formaldehyde resin obtained in the present invention is excellent in moisture resistance and adhesion to metal. It can be used as a molding material, epoxy resin or its curing agent.

The aromatic hydrocarbon formaldehyde resin is usually obtained by reacting aromatic hydrocarbons such as xylene and mesitylene with formalin for 2 to 8 hours under reflux under an acid catalyst. Those using xylene are called xylene formaldehyde resins, and those using mesitylene are called mesitylene formaldehyde resins. The aromatic hydrocarbon used as a raw material for the aromatic hydrocarbon formaldehyde resin used in the present invention includes toluene, xylene three isomers, mesitylene, pseudocumene, monocyclic aromatic hydrocarbon compounds having 10 or more carbon atoms, and And polycyclic aromatic hydrocarbon compounds such as naphthalene and methylnaphthalene. Mixtures of these can also be used.
In the present invention, an aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in the aromatic ring of 1.8 to 3.0 and an acetal value of 0 to 2.2 mol / Kg is described in JP-A-61-228013. To obtain an aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in the aromatic ring of 1.8 to 3.0 and an acetal value of 2.3 to 4 mol / Kg, and then the aromatic ring proton reaction. It is preferable to obtain an aromatic hydrocarbon formaldehyde resin having an average number of 1.8 to 3.0 and an acetal number of 2.3 to 4 mol / Kg by a method of removing formalin by steam distillation under an acidic catalyst.
An aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in the aromatic ring of 1.8 to 3.0 and an acetal value of 2.3 to 4 mol / Kg has a molar ratio of formaldehyde to aromatic hydrocarbon of 1: 2-5, the concentration of sulfuric acid in the component consisting of formaldehyde, water, and sulfuric acid is 15-35% by weight, the reaction temperature is 80-110 ° C., and the stirring speed is low enough to observe the interface between the oil layer and the water layer. Can be synthesized.
Further, as described in JP-A-11-92543, the molar ratio of the aromatic hydrocarbon to formaldehyde used is 1: 1 to 5, and the molar ratio of the aromatic hydrocarbon to aliphatic alcohol used is 1 : 0.5 to 2.0, and the synthesis can also be performed by setting the sulfuric acid concentration in the component consisting of formaldehyde, water, and sulfuric acid to 30 to 50% by weight and the reaction temperature to 40 to 80 ° C.

In the present invention, the number of proton reactions in the aromatic ring of the aromatic hydrocarbon formaldehyde resin that is the raw material can be measured by H-NMR, and is about 1.8 to 2.6 ppm of methyl protons and about 6.9 ppm of aromatic rings. It is obtained from the integral value of directly connected protons.
Specifically, when the integral value of methyl protons of metaxylene in the vicinity of 1.8 to 2.6 ppm of metaxylene formaldehyde resin by H-NMR measurement is 6, which is the number of methyl proton equivalents present in one molecule of metaxylene. The integral value of the proton directly connected to the aromatic ring in the vicinity of 6.9 ppm is calculated. The value is an average value of the number of equivalents of metaxylene ring direct protons present per metaxylene molecule after the reaction. The value obtained by subtracting the calculated value from 4 which is the number of proton equivalents directly attached to the metaxylene ring before the reaction was defined as “average number of proton reactions in the aromatic ring”.

A cured product using a phenol-modified aromatic hydrocarbon formaldehyde resin, which is excellent in reactivity with phenols and obtained by reaction with phenols, has excellent cured properties. It is necessary that the number is 1.8 to 3.0 on average by H-NMR measurement, preferably 1.9 to 2.5.
When the average number of proton reactions in the aromatic ring of the raw material resin is 1.8 or more and 3.0 or less, there are many active groups that react with phenols, and the cured product using the obtained phenols-modified aromatic hydrocarbon formaldehyde resin Is preferable because a sufficient crosslinking density is obtained and the physical properties are good.

  Acetal bond among methylene bond, dimethylene ether bond, acetal bond, and methylol group, acetal group, and methoxymethyl group in aromatic nuclei at the end of aromatic hydrocarbon formaldehyde resin as raw material. And the acetal group acts as a formalin component when reacting with the third component, and becomes a phenol novolak component in the reaction with phenols. Therefore, if the phenol novolac component is contained in a large amount, the moisture resistance and the effect of introducing a xylene structure Adhesiveness with metal is difficult to express and is not preferable.

An acetal value is a numerical value of the acetal bond and acetal group content in an aromatic hydrocarbon formaldehyde resin. An unreacted 2,6-xylenol, 2,6-xylenol-modified aromatic hydrocarbon formaldehyde resin, tetramethyl is present in the reaction liquid when the aromatic hydrocarbon formaldehyde resin and 2,6-xylenol are reacted under acidic conditions. Bisphenol F (bis (4-hydroxy-3,5-dimethyl) phenylmethane) is present. Tetramethylbisphenol F is a substance derived from acetal bond and acetal group, and acetal value is obtained by quantifying the content of acetal bond and acetal group by quantifying tetramethylbisphenol F (“thermosetting” Resin ", Synthetic Resin Industry Association, 1986, Vol. 7, No. 2, p.
When the acetal number exceeds 2.2 mol / Kg, it is not preferable because the effect of introducing the xylene structure is not sufficiently exhibited in the reaction product with the third component.

In the method of removing formalin by steam distillation of an aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in the aromatic ring of 1.8 to 3.0 and an acetal number of 2.3 to 4 mol / Kg under an acidic catalyst, Acetal bonds and acetal groups of aromatic hydrocarbon formaldehyde resins undergo decomposition under acidic conditions. At this time, the acetal number can be reduced to 0 to 2.2 mol / Kg by removing formalin from the system by steam distillation.
Examples of the acidic catalyst used for removing formalin by steam distillation include sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, and oxalic acid. Paratoluenesulfonic acid and oxalic acid are preferred. The amount of paratoluenesulfonic acid added is preferably 10 to 5000 ppm, more preferably 100 to 500 ppm, based on the amount of the aromatic hydrocarbon formaldehyde resin. The amount of oxalic acid added is preferably 2 to 15% by weight, more preferably 3 to 10% by weight, based on the amount of resin. When the amount of catalyst is small, the catalytic effect does not appear. If the amount of the catalyst is excessive, the self-condensation reaction occurs vigorously and gelation occurs. The treatment temperature is preferably 100 to 200 ° C, more preferably 130 to 180 ° C. The treatment time is influenced by the amount of catalyst and the treatment temperature, but is preferably 1 to 10 hours, and more preferably 1 to 6 hours.
The acetal value of the aromatic hydrocarbon formaldehyde resin after the steam distillation treatment is preferably 0 to 2.2 mol / Kg, more preferably 1 to 2.0 mol / Kg.

  Examples of the phenols used in the present invention include phenol, cresols, xylenols, butylphenol, octylphenol, nonylphenol, cardanol, terpenephenol, etc. Among them, phenol is preferable. The phenols may be used alone or as a mixture thereof.

  In the present invention, examples of the acidic catalyst used for the condensation reaction include sulfuric acid, hydrochloric acid, paratoluenesulfonic acid, oxalic acid and the like. Paratoluenesulfonic acid and oxalic acid are preferred. The addition amount of p-toluenesulfonic acid is preferably 0.01 to 0.5% by weight, more preferably 0.02 to 0.1% by weight, based on the total amount of resin, phenols and acidic catalyst. The amount of oxalic acid added is preferably 3 to 15% by weight, more preferably 5 to 10% by weight, based on the total amount of resin, phenols and acidic catalyst.

  The reaction charge amount of the aromatic hydrocarbon formaldehyde resin and phenol used in the present invention is preferably 80 to 500 parts by weight, more preferably 90 to 400 parts by weight with respect to 100 parts by weight of the aromatic hydrocarbon formaldehyde resin. is there. The above range is preferable because gelation can be suppressed in the reaction, the remaining amount of unreacted phenols can be reduced, and the burden of distillation operation is small.

Although the reaction temperature and reaction time vary depending on the type of phenols used, the type of catalyst, and the amount, the reaction temperature is about 95 ° C. to 160 ° C., and the reaction time is preferably about 1 to 6 hours. Since the reaction between the aromatic hydrocarbon formaldehyde resin and the phenols is a condensation reaction, water and methanol are produced. However, the temperature may be controlled by distilling or refluxing the produced liquid. When the distillation reaction is performed, the reaction temperature is preferably about 140 ° C. to 160 ° C., and the reaction time is preferably about 1 hour to 3 hours.
In the reflux reaction, the reaction temperature is preferably about 95 ° C to 130 ° C, and the reaction time is preferably about 1 hour to 3 hours.

  Unreacted phenols in the resin can be reduced to 0.2% by weight by removing unreacted phenols by distillation under a vacuum of 10 to 30 Torr after the reaction, or by distilling off by steam distillation. It is.

  After removing unreacted phenol, when removing the catalyst by a method such as neutralization or washing with water, it is desirable to dilute with an organic solvent. As the organic solvent, methyl ethyl ketone and metaxylene are preferable. After washing with water, the organic solvent is removed by vacuum distillation or steam distillation to obtain a phenol-modified aromatic hydrocarbon formaldehyde resin.

  The phenol-modified aromatic hydrocarbon formaldehyde resin thus obtained is excellent in moisture resistance and metal adhesion, and can be used as a thermosetting resin as a molding material, an epoxy resin, or a curing agent thereof.

The present invention will be specifically described below with reference to examples. “%” Means “% by weight” unless otherwise specified. The evaluation method of a phenols modified aromatic hydrocarbon formaldehyde resin is shown. The adhesion to the metal was evaluated by a tensile shear test, and the moisture resistance was evaluated by the height of the absolute value of the tensile shear bond strength by performing a tensile shear test after wetting (PCT).
<Analyzing method of proton reaction number in aromatic ring of raw resin>
H-NMR measurement was used. Around 6.9 ppm when the integral value of methyl protons of metaxylene in the vicinity of 1.8 to 2.6 ppm of metaxylene formaldehyde resin by H-NMR measurement is 6 which is the number of methyl proton equivalents present in one molecule of metaxylene. The integral value of the proton directly connected to the aromatic ring is calculated. The value is an average value of the number of equivalents of metaxylene ring direct protons present per metaxylene molecule after the reaction. The value obtained by subtracting the calculated value from 4 which is the number of proton equivalents directly attached to the metaxylene ring before the reaction was defined as “average number of proton reactions in the aromatic ring”.
<Acetal number>
The sample and 2.6 xylenol are reacted under PTSA catalyst. The produced tetramethylbisphenol F is quantified by gas chromatography measurement. GC measurement was performed by an internal standard method using biphenyl ether as an internal standard.
The acetal value was calculated by the following formula.
Acetal number (mol / Kg) = A × 1000 / B × C
A: Tetramethylbisphenol F amount (g)
B: Amount of xylene resin (g)
C: Molecular weight of tetramethylbisphenol <hydroxyl equivalent>
The sample was acetylated with an excess amount of acetic anhydride in a pyridine solvent, and the excess acetic anhydride that was not consumed in the acetylation reaction was titrated with an aqueous sodium hydroxide solution.
<Melt viscosity>
I. C. Measurements were made at 150 ° C. using an I corn and viscometer.
<Unreacted phenol content>
Measured by gas chromatography. Methyl benzoate was measured by an internal standard method as an internal standard.
<Tensile shear test>
The resins, curing accelerators, and silica shown in Table 1 were kneaded (set temperature: 105 ° C., rotation speed: 30 rpm, kneading time: 180 seconds) with a lab plast mill. Three kinds of materials to be bonded were changed to prepare test pieces, and a tensile shear test (based on JIS-K6850) was performed to determine the tensile shear bond strength.
Materials to be bonded: copper, silver plating (base 42 alloy, 0.2 μm), palladium plating (base 42 alloy, 0.4 μm)
Adhered piece size: 50 mm (L) x 25 mm (W) x 2 mmt)
Curing conditions: Curing for 10 minutes at 175 ° C. Post curing conditions: After 6 hours at 175 ° C., 4 hours at 200 ° C. Shearing conditions: Crosshead speed 0.5 mm / min
Wet (PCT) conditions: A tensile shear test was carried out after holding at 121 ° C. (2 atm) for 50 hours.
In Table 1, the biphenyl type epoxy resin is Japan Epoxy Resin Co., Ltd. YH-4000H, the phenol novolac resin is Gunei Chemical Co., Ltd. PSM 4261, the phenol aralkyl resin is Mitsui Chemicals Co., Ltd. Millex XLC-LL, and the silica is Electrochemical Co., Ltd. FB-820, triphenylphosphine was used as a curing accelerator.
In Table 1, before PCT is the tensile shear bond strength before wetting, and after PCT is the tensile shear bond strength after wetting.

<Production Example 1>
Production example 1 of aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in the aromatic ring of 1.8 to 3.0 and an acetal value of 0 to 2.2 mol / Kg.
A 2 liter separable flask equipped with a thermometer, a Liebig condenser, a stirrer, and a nitrogen introduction tube was charged with xylene formaldehyde resin (Mitsubishi Gas Chemical Co., Ltd., Nikanol G, average number of proton reactions in the aromatic ring of 1.9, acetal number of 3.5 mol) / Kg) 1000 g, paratoluenesulfonic acid (Wako Pure Chemical Industries, Ltd.-special grade reagent) 0.5 g (0.05% with respect to the amount of xylene formaldehyde resin) was added, and steam distillation was performed at 130 ° C. for 1 hour to remove formalin. As a result, 950 g of a yellow resin was obtained. The average number of proton reactions in the aromatic ring of this resin was 1.9, and the acetal value was 2.0 mol / Kg.

<Production Example 2>
Production example 2 of aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in the aromatic ring of 1.8 to 3.0 and an acetal number of 0 to 2.2 mol / Kg.
A 2 liter separable flask equipped with a thermometer, a Liebig condenser, a stirrer, and a nitrogen introduction tube was added to a xylene formaldehyde resin (Mitsubishi Gas Chemical Co., Ltd., Nikanol GL20, an average number of proton reactions in an aromatic ring of 2.1, an acetal number of 2.9 mol). / Kg) 1000 g, oxalic acid (Wako Pure Chemicals Co., Ltd.-special grade reagent) 50 g (5% with respect to the amount of xylene formaldehyde resin) was added, and steam distillation was performed at 130 ° C. for 1 hour to remove formalin to obtain 950 g of a yellow resin. It was. The average number of proton reactions in the aromatic ring of this resin was 2.1, and the acetal value was 1.6 mol / Kg.

<Example 1>
Synthesis of phenol-modified xylene formaldehyde resin (Resin A)
Charged 500 g of phenol (Wako Pure Chemicals Co., Ltd.-special grade reagent) into a 2 liter separable flask equipped with a thermometer, condenser, reflux condenser, stirrer, and nitrogen introduction tube, heated to 130 ° C, and manufactured while paying attention to temperature rise 500 g of the resin obtained in Example 1 (0.052% residual catalyst amount, 0.026% catalyst amount with respect to the total charged amount) was added in portions. The reaction was conducted at a reflux temperature of 98 ° C. for 1 hour. After the reaction, the temperature was raised to 170 ° C., dehydration treatment, and distillation under reduced pressure to obtain 700 g of a phenol-modified xylene resin. The melt viscosity was 350 mPa · S / 150 ° C. and the hydroxyl group equivalent was 195 g / eq.

<Example 2>
Synthesis of phenol-modified xylene formaldehyde resin (Resin B)
A 2 liter separable flask equipped with a thermometer, condenser, reflux condenser, stirrer, and nitrogen introduction tube was charged with 500 g of phenol (Wako Pure Chemical Industries, Ltd.-special grade reagent) and 50 g of oxalic acid (Wako Pure Chemical Industries, Ltd.-special grade reagent). After heating to 130 ° C., 500 g of the resin obtained in Production Example 2 (remaining catalyst amount 5.26%, catalyst amount with respect to the total charged amount 7.27%) was added in portions while paying attention to the temperature rise. The reaction was conducted at a reflux temperature of 98 ° C. for 1 hour. After the reaction, the temperature was raised to 170 ° C., dehydration treatment, and distillation under reduced pressure to obtain 700 g of a phenol-modified xylene resin. The melt viscosity was 380 mPa · S / 150 ° C., and the hydroxyl group equivalent was 200 g / eq.

<Comparative Example 1>
Synthesis of phenol-modified xylene formaldehyde resin (Resin C)
In a 2 liter separable flask equipped with a thermometer, condenser, reflux condenser, stirrer, and nitrogen inlet tube, 500 g of phenol (Wako Pure Chemical Industries, Ltd.-special grade reagent), 0.5 g of paratoluenesulfonic acid (Wako Pure Chemical Industries, Ltd.-special grade Reagent), and heated to 130 ° C, paying attention to the temperature rise, xylene formaldehyde resin (Mitsubishi Gas Chemical Co., Ltd., Nikanol G, average number of substituents per aromatic ring 1.9, acetal number 3.6 mol / Kg) 500 g Was added in portions. The catalyst was reacted at a reflux temperature of 98 ° C. for 1 hour (0.05% of catalyst based on the total amount charged). After the reaction, the temperature was raised to 170 ° C., dehydration treatment, and distillation under reduced pressure to obtain 700 g of a phenol-modified xylene resin. The melt viscosity was 400 mPa · S / 150 ° C. and the hydroxyl group equivalent was 185 g / eq.
<Comparative example 2>
Evaluation was carried out without using a phenol-modified xylene formaldehyde resin as a curing agent.

Resin (A), (B), (C) and phenol novolak resin obtained in the above examples and comparative examples, the blending ratio of the epoxy resin composition when using the phenol aralkyl resin as a curing agent for the epoxy resin, and The properties of the cured product are shown in Table 1.

From the results in Table 1, the cured product using the phenol-modified xylene formaldehyde resin of the present invention shows excellent values for moisture resistance and adhesion to metal.

Claims (7)

An aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in an aromatic ring of 1.8 to 3.0 and an acetal value of 0 to 2.2 mol / Kg and a phenol are subjected to a condensation reaction in the presence of an acidic catalyst. A process for producing a phenol-modified aromatic hydrocarbon formaldehyde resin. The method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 1, wherein the aromatic hydrocarbon formaldehyde resin is at least one selected from the group consisting of a xylene formaldehyde resin and a mesitylene formaldehyde resin. The method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 1 or 2, wherein the acidic catalyst is p-toluenesulfonic acid or oxalic acid. An aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in an aromatic ring of 1.8 to 3.0 and an acetal value of 2.3 to 4 mol / Kg is removed by removing formalin by steam distillation under an acidic catalyst. The production of phenol-modified aromatic hydrocarbon form according to claim 1, wherein an aromatic hydrocarbon formaldehyde resin having an average number of proton reactions in the ring of 1.8 to 3.0 and an acetal value of 0 to 2.2 mol / Kg is obtained. Method. The method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 4, wherein the acidic catalyst is paratoluenesulfonic acid or oxalic acid. The method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 4, wherein the steam distillation is performed at 100 to 200 ° C for 1 to 10 hours.   The method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 1, wherein after the condensation reaction, unreacted phenols are removed to make the content 0.2 wt% or less.