JP3510869B2 - Phenolic polymer, its production method and its use - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel phenolic polymer useful as a molding material, various binders, coating materials, laminated materials, etc., a method for producing the same, and a composition using the same as an epoxy resin curing agent or curing thereof. Regarding things. In particular, it relates to a phenolic polymer having low water absorption, low elastic modulus and low melt viscosity, which is useful as a curing agent in an epoxy resin type semiconductor encapsulating material.

[0002]

2. Description of the Related Art As a semiconductor encapsulation method, resin encapsulation with an epoxy resin is generally used from the viewpoint of economical efficiency, productivity and physical properties. Among them, orthocresol novolac type epoxy resin and phenol novolac curing agent are used. Resin encapsulations consisting of and an inorganic filler such as silica have been widely used. However, in recent years, the required performance of the encapsulant has changed significantly with the increase in the size of the LSI chip, the thinner / smaller package, and the change in the mounting method. It is becoming difficult to adequately respond in terms of heat resistance and reliability. For example, during heat treatment during soldering, cracking or peeling of the package due to rapid vaporization and expansion of moisture absorption becomes a problem.

Therefore, it is desired to develop an epoxy resin or a curing agent which has a low hygroscopic property and a low elastic modulus at the soldering temperature. In response to such a demand, a method using a phenol aralkyl resin (Japanese Patent Publication No. 47-13782, Japanese Patent Publication No. 47-15111, etc.) as a curing agent has been put into practical use. Phenol aralkyl resin is obtained by reacting a phenol compound with an aromatic compound having two halomethyl groups, alkoxymethyl groups, hydroxymethyl groups, etc., and has the effect of lowering the OH group concentration, resulting in low water absorption and heat. It was intended to lower the elasticity, and some effects were recognized, but it was not yet sufficient.

Recently, a phenol biphenyl aralkyl resin of a type using bis (methoxymethyl biphenyl) as an aromatic compound having two or more alkoxymethyl groups has been proposed (Japanese Patent No. 3122834 etc.), and some improvement has been made. However, even in this case, it cannot be said to be sufficiently satisfactory. Particularly in the case of large and thin packages, materials that can support lead-free solder and have a lower water absorption and a lower elastic modulus are required in the situation where an increase in soldering temperature cannot be avoided.

Under these circumstances, it has been proposed to use polycyclic aromatic compounds such as naphthol (Japanese Patent Laid-Open No. 9-176262), but it is possible to use phenol excessively in order to increase the melt viscosity. It is indispensable and is not necessarily a sufficient improvement.

In addition to these, naphthol aralkyl resin and petroleum pitch copolymerized with formaldehyde together with phenol, addition reaction product of divinylbenzene and phenol, addition reaction product of dicyclopentadiene and phenol, etc. are proposed. It has not reached the point of satisfying the characteristics.

Further, benzylated products of specific polyphenols have also been proposed (JP-A-8-120039).
No.), it is disclosed that an epoxy resin composition excellent in heat resistance, low water absorption, mechanical strength, etc. can be obtained, but a polyphenol in which a phenol skeleton, which is said to be particularly preferable, is linked by a methylene group or a thioether bond is disclosed. The benzylated products lack water absorption and elastic modulus, and are completely unsatisfactory as lead-free solder compatible materials.

[0008]

Therefore, an object of the present invention is to provide a novel phenol capable of achieving low viscosity, low water absorption and low elasticity when used as a curing agent in an epoxy resin curing system for semiconductor encapsulation. The purpose is to provide a polymer. Another object of the present invention is to provide a method for efficiently producing such a phenolic polymer.
Still another object of the present invention is to provide use of such a phenolic polymer as an epoxy resin curing agent, and a curable composition blended with an epoxy resin and a cured product thereof.

[0009]

That is, the present invention relates to a phenolic polymer represented by the following general formula (1).

[Chemical 8] (In the formula, Ar is an aryl group, R ¹ and R ² are each hydrogen or a methyl group, R ³ , R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms, and a, b and c are: 0 ≦ a ≦
2, 0 ≦ b ≦ 2, 1 ≦ c ≦ 5, (a + bc) / (1+
c) is in the range of 0.2 to 1.5, and c b's are the same or different from each other. )

The present invention also provides a phenol biphenylaralkyl resin represented by the following general formula (2) and a general formula (3).
The present invention relates to a method for producing a phenolic polymer represented by the above formula (1), which comprises reacting the benzyl compound represented by the formula (1) in the presence of an acid catalyst.

[Chemical 9] (In the formula, R ³ , R ⁴ and R ⁵ are each hydrogen or carbon 1
To 4 alkyl groups, c is 1 ≦ c ≦ 5)

[Chemical 10] (In the formula, Ar is an aryl group, R ¹ and R ² are each hydrogen or a methyl group, and R ⁶ is hydrogen or an alkyl group having 1 to 4 carbon atoms)

The present invention also provides a phenol biphenylaralkyl resin represented by the above general formula (2) and the general formula (4).
The present invention relates to a method for producing a phenolic polymer represented by the above general formula (1), which comprises reacting a benzyl halide represented by the formula (1) in the presence of water.

[Chemical 11] (In the formula, Ar is an aryl group, R ¹ and R ² are each hydrogen or a methyl group, and X is Cl, Br or I).

The phenol biphenylaralkyl resin represented by the general formula (2) is obtained by reacting the biphenyl compound represented by the general formula (5) with the phenol represented by the general formula (6) in the presence of an acid catalyst. It can also be obtained by reacting the dihalomethylbiphenyl compound represented by the general formula (7) with the phenol represented by the general formula (6) in the presence of water.

[Chemical 12] (In the formula, R is hydrogen or an alkyl group having 1 to 4 carbon atoms,
R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms)

[Chemical 13] (In the formula, R ³ is hydrogen or an alkyl group having 1 to 4 carbon atoms)

[Chemical 14] (In the formula, X is Cl, Br or I, R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms)

The present invention also provides a curing agent for an epoxy resin comprising a phenolic polymer of the above general formula (1) and an epoxy resin composition containing the phenolic polymer of the above general formula (1) and an epoxy resin. Relates to a cured epoxy resin obtained by curing the same.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION
In the case of a nor polymer, Ar is an aryl group.
For example, phenyl, naphthyl, biphenyl, methylpheni.
Examples of groups such as benzyl, benzylphenyl, and methylnaphthyl
can do. Also R¹, R^TwoAre hydrogen or
It is a methyl group, and preferably both are hydrogen.
Furthermore R ^Three, R^Four, R⁵Are hydrogen or 1 to 1 carbon atoms, respectively.
4 alkyl groups such as methyl, ethyl, isopropyl
, N-propyl, isobutyl, n-butyl, t-butyl
An alkyl group such as ru. In general formula (1)
As the polymerized units of the biphenyl skeleton, 4,4'-type,
There are various types such as 2,4'-type and 2,2'-type.
Particularly, 4,4'-type is preferable.

Further, c is 1≤c≤5, preferably 1≤c≤.
4 is satisfied. The meaning of this formula means that c is an integer of 5 or less if the phenolic polymer has a single degree of polymerization, but when the phenolic polymer is a mixture of different degrees of polymerization, That is, when c is a mixture of a plurality of kinds, it means that the average value is a value of 1 to 5, and as long as the average value falls within this range, c is partially 6 or more, for example 6 to. The thing of 10 may be mixed. In general, a mixture of phenolic polymers having different degrees of polymerization is preferable because it is easier to produce and has a low melt viscosity.

Also in the above general formula, a and b are
0 ≦ a ≦ 2 and 0 ≦ b ≦ 2, respectively, and (a + b
c) / (1 + c) is 0.2 to 1.5, preferably 0.4
Is in the range of 1.2, and the c b's are the same or different from each other. When c is larger than 1, some of the b benzyl groups are bound to the terminal phenol skeleton and some are bound to the phenol skeleton in the molecular chain. It is considered that there are more people on average.

In the above general formula, when a phenolic polymer having a value of c larger than 5 is used, the melt viscosity tends to be high and the moldability tends to be impaired. Therefore, the range is preferably such that c is 5 or less. . Also (a + bc) /
When the value of (1 + c) is smaller than the above range, the water absorption rate and the elastic modulus in the soldering temperature range are not sufficiently reduced, and when the value becomes too large, the epoxy resin may be used as a curing agent. Moreover, the curing speed becomes slow, which is not preferable.

Although it should be determined by the values of a, b and c, the above-mentioned phenolic polymer also has a melt viscosity at 150 ° C. of 700 mPa · s or less, preferably 500 mPa · s or more. And a hydroxyl value of 220 to 350 g / eq, especially 230 to
It is preferably in the range of 330 g / eq.

Typical examples of the above-mentioned phenolic polymer include R ¹ , R ² , R ³ , R ⁴ and R in the general formula (1).
⁵ is hydrogen, Ar is a phenyl group, and the polymer unit of the biphenyl skeleton is 4,4′-type, which is represented by the general formula (8).

[Chemical 15]

Such a phenolic polymer can be analyzed by mass spectrum analysis (MS), proton NMR (H-NM).
R), gel permeation chromatography (GPC), hydroxyl equivalent and the like. FIG. 1 is a mass spectrum chart of the phenolic polymer obtained in Example 1 and represented by the above formula (8). Table 1 shows the relationship between the molecular weight peak of the mass spectrum and c and a + bc in the formula (8).

[0021]

[Table 1]

FIG. 2 is a proton NMR chart of the above-mentioned phenolic polymer, in which aromatics (phenol nucleus, biphenyl nucleus, phenyl nucleus derived from benzyl group) are 6.5 to 5.
7.6 ppm, methylene 3.6-4.1 ppm, OH
A group was detected at 8.2 to 9.5 ppm, which shows that phenol has a structure in which it is linked to a biphenyl group through a benzyl group and a methylene bond.

FIG. 3 is a GPC chart of the above-mentioned phenolic polymer, and FIG. 4 is a raw material thereof, and in the general formula (2), R ³ , R ⁴ and R ⁵ are each hydrogen, and the polymerization of the biphenyl skeleton portion is carried out. The following formula (9) whose unit is 4,4′-type
GP of phenol biphenyl aralkyl resin represented by
It is a C chart.

[Chemical 16]

As is clear from the comparison between FIG. 3 and FIG. 4, the above-mentioned phenolic polymer has a molecular weight distribution, and the benzylation increases the molecular weight, and the benzylation leads to the formation of a phenol nucleus. It can be seen that the number of peaks increased further due to the distribution (variation) of the number of benzyl groups substituted.

Further, the hydroxyl equivalent of 303 is obtained by acetylating the OH group of the phenolic polymer with an excess of acetic anhydride and quantifying the acetic anhydride consumed at that time.
In the general formula (8), the value of g / eq is c = 2.
It is in very good agreement with the hydroxyl group equivalent (calculated value) in the case of 0 and (a + bc) / (1 + c) = 1.0.

From the above, it can be concluded that the phenolic polymer has a structure represented by the general formula (8).

The phenolic polymer represented by the above general formula (1) can be efficiently produced by the following method. The first method can be obtained by reacting a phenol biphenylaralkyl resin represented by the general formula (2) with a benzyl compound represented by the general formula (3) in the presence of an acid catalyst.

In the general formula (2) of the phenolbiphenylaralkyl resin, R ³ , R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, isopropyl, n-propyl, isobutyl and n. Alkyl groups such as butyl and t-butyl. Also, c is
It satisfies 1 ≦ c ≦ 5, preferably 1 ≦ c ≦ 4. The meaning of this formula is that if the phenol biphenyl aralkyl resin is of a single degree of polymerization, c is an integer of 5 or less, but when the phenol biphenyl aralkyl resin is a mixture of different degrees of polymerization, That is, when c is a mixture of plural kinds, the average value is 1 to 5
It means that the average value is within this range, and partially c may be 6 or more, for example, 6 to 10 may be mixed.

In the general formula (3), Ar is an aryl group, for example, phenyl, naphthyl, biphenyl,
Examples thereof include groups such as methylphenyl, benzylphenyl and methylnaphthyl. R ¹ and R ² are each hydrogen or a methyl group, and preferably both are hydrogen. R ⁶ is hydrogen or an alkyl group having 1 to 4 carbon atoms, for example, an alkyl group such as methyl, ethyl, isopropyl, n-propyl, isobutyl, n-butyl and t-butyl. Specific examples of the benzyl compound represented by the general formula (3) include benzyl alcohol, o-methylbenzyl alcohol, m-methylbenzyl alcohol, p-methylbenzyl alcohol, p-ethylbenzyl alcohol, p-isopropylbenzyl alcohol,
pt-butylbenzyl alcohol, p-cyclohexylbenzyl alcohol, p-phenylbenzyl alcohol, 2-naphthylcarbinol, 7-methyl-2-naphthylcarbinol and their nuclear substitution isomers, α-methylbenzyl alcohol, α , α-dimethylbenzyl alcohol, benzyl methyl ether, o-methylbenzyl methyl ether, m-methylbenzyl methyl ether,
p-Methylbenzyl methyl ether, p-ethylbenzyl methyl ether and their nuclear substitution isomers, benzyl ethyl ether, benzyl isopropyl ether, benzyl n-propyl ether, benzyl isobutyl ether, benzyl n-butyl ether, p-methyl benzyl methyl ether And nuclear substitution isomers thereof.

As the acid catalyst usable in the above reaction, inorganic acids such as phosphoric acid, sulfuric acid and hydrochloric acid, oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid,
Organic acids such as fluoromethanesulfonic acid, and Friedel-Crafts catalysts such as zinc chloride, stannic chloride, ferric chloride, and diethylsulfate can be used alone or in combination.

In the above reaction, for example, 0.2 to 1.5 molecules of the benzyl compound represented by the general formula (3) per one molecule of the phenol skeleton in the phenol biphenylaralkyl resin represented by the general formula (2) is used. , Preferably 0.4-
Use the amount of 1.2 molecules and add 60 to 18 by adding an acid catalyst.
1-10 at a temperature of 0 ° C., preferably 70-160 ° C.
It is better to do this by maintaining the time. The benzyl compounds can be added all at once to carry out the reaction, but for example, the reaction can also be carried out while the benzyl compounds are added dropwise with stirring to a system consisting of a phenol biphenylaralkyl resin and an acid catalyst. After completion of the reaction, if necessary, the catalyst may be removed by a general method such as distillation or washing, or
Alternatively, after deactivating the catalyst with the base component, the reaction product is taken out from the reaction vessel and cooled to obtain the desired phenolic polymer.

The second method for obtaining the phenolic polymer represented by the general formula (1) is to prepare a phenol biphenylaralkyl resin represented by the general formula (2) and a benzyl halide represented by the general formula (4). This is a method of reacting in the presence of water.

In the general formula (4), Ar is an aryl group, and examples thereof include phenyl, naphthyl, biphenyl, methylphenyl, benzylphenyl and methylnaphthyl groups. R ¹ and R ² are each hydrogen or a methyl group, and preferably both are hydrogen. X is Cl, Br or I. Specific examples of benzyl halides include benzyl chloride, benzyl bromide, benzyl iodide, o-methylbenzyl chloride, m-methylbenzyl chloride,
p-methylbenzyl chloride, p-ethylbenzyl chloride, p-isopropylbenzyl chloride, p-
t-butylbenzyl chloride, p-cyclohexylbenzyl chloride, p-phenylbenzyl chloride,
2-naphthylmethyl chloride, 7-methyl-2-naphthylmethyl chloride and their nuclear substitution isomers, α-
Examples thereof include methylbenzyl chloride and α, α-dimethylbenzyl chloride.

Also in this reaction, the benzyl halide represented by the general formula (4) is contained in an amount of 0.2 to 1.5 per one molecule of the phenol skeleton in the phenol biphenylaralkyl resin.
The amount of the molecule, preferably 0.4 to 1.2 molecule, is used, and the temperature is maintained at 60 to 180 ° C., preferably 70 to 160 ° C. for about 1 to 10 hours in the coexistence of water as a reaction initiator. It is better to do it by The amount of water that coexists is
About 100 ppm or more is effective with respect to the total weight of the phenol biphenyl aralkyl resin and the benzyl halides, while it is meaningless to make it exist in a too large amount, it is preferable to set it to about 0.5% by weight or less. . In this reaction, an acid catalyst as described above can be used in combination if necessary.

The phenol biphenyl aralkyl resin represented by the general formula (2) can be efficiently produced by the following two methods. The first method is a method of reacting a biphenyl compound represented by the general formula (5) with a phenol represented by the general formula (6) in the presence of an acid catalyst.

In the general formula (5), R is hydrogen or an alkyl group having 1 to 4 carbon atoms, such as methyl, ethyl, isopropyl, n-propyl, isobutyl, n-butyl, t-.
It is a group such as butyl, and two Rs may be the same or different from each other. Further, R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms, for example, a group as exemplified in the above R. Specific examples of the biphenyl compound represented by the general formula (5) include 4,4′-dihydroxymethylbiphenyl, 2-methyl-4,4′-dihydroxymethylbiphenyl and 2,2′-dimethyl-4,4′-. dihydroxymethyl biphenyl, 4,4'-dimethyl preparative carboxymethyl biphenyl, 4,4'-diethyl preparative carboxymethyl biphenyl, 4,4'-diisopropoxy-methylbiphenyl,
4,4'-di-t-butoxymethylbiphenyl, 2-methyl-4,4'-dimethoxymethylbiphenyl, 2,
Examples thereof include 2'-dihydroxymethylbiphenyl and 2,4'-dihydroxymethylbiphenyl. Particularly preferred biphenyl compounds is 4,4'-dihydroxy-methyl-biphenyl and 4,4'-dimethyl preparative carboxymethyl biphenyl.

The phenols represented by the general formula (6) include phenol, o-cresol, m-cresol,
Examples thereof include p-cresol, o-ethylphenol, p-ethylphenol, p-isopropylphenol, pn-butylphenol, p-isobutylphenol, pt-butylphenol, and nuclear-substituted isomers thereof.

As the acid catalyst used for the reaction of the above-mentioned biphenyl compound and phenol, the above-mentioned examples which can be used for the reaction of the phenol-biphenylaralkyl resin of the general formula (2) and the benzyl compound of the general formula (3) are mentioned. It can be selected from among the acid catalysts.

The reaction ratio between the biphenyl compound of the general formula (5) and the phenols is such that the average degree of polymerization c of the phenol biphenylaralkyl resin is in the range of 1 to 5, and the above is based on 1 mol of the phenols. Biphenyl compound 0.03 to 0.70 mol, especially 0.10 to 0.5
A proportion of 0 mol is preferable.

The reaction is carried out by adding an acid catalyst in an amount of about 0.004 to 6% by weight based on the total amount of the biphenyl compound and phenols, and at a temperature of about 60 to 180 ° C., preferably about 80 to 160 ° C., for 1 to 10%. It is better to do this by maintaining the time. After completion of the reaction, the phenol biphenylaralkyl resin represented by the general formula (2) can be obtained by distilling off unreacted phenols. In this case, when an acid catalyst is contained, it can be used as it is for the reaction with the benzyl compound of the general formula (3). When it does not contain an acid catalyst, it can be used for the reaction with the benzyl compound represented by the general formula (3) by newly adding an acid catalyst, and can also be used for the reaction with the benzyl halides represented by the general formula (4). can do.

The second method for producing the phenol biphenyl aralkyl resin of the general formula (2) is the presence of dihalomethylbiphenyl compound of the general formula (7) and phenols of the general formula (6) in the presence of water. It is a method of reacting below. In the general formula (7), R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms, for example, groups such as methyl, ethyl, isopropyl, n-propyl, isobutyl, n-butyl and t-butyl. . Specific examples of the dihalomethylbiphenyl compound include 4,4′-dichloromethyldiphenyl, 4,4′-dibromomethyldiphenyl,
4,4'-diaionomethyldiphenyl, 2-methyl-
4,4'-dichloromethyldiphenyl, 2,2'-dimethyl-4,4'-dichloromethyldiphenyl, 2,2 '
-Dichloromethyldiphenyl, 2,4'-dichloromethyldiphenyl and the like can be mentioned. Of these, particularly preferred is 4,4'-dichloromethyldiphenyl.

The reaction ratio of the dihalomethylbiphenyl compound and the phenols is such that the average degree of polymerization c of the phenolbiphenylaralkyl resin is in the range of 1 to 5, and the above dihalomethyl is used for 1 mol of the phenols. Biphenyl compound in an amount of 0.03 to 0.70 mol, especially 0.1
The proportion is preferably 0 to 0.50 mol.

The reaction between the two is preferably carried out in the coexistence of water as a reaction initiator, by maintaining the temperature at about 60 to 180 ° C., preferably about 80 to 160 ° C. for about 1 to 10 hours. The amount of water to coexist is effective when it is about 100 ppm or more, and it is meaningless to make it exist in a too large amount. Therefore, for example, 0.5 wt% relative to the total amount of the dihalomethylbiphenyl compound and phenols. It is good to set it to about% or less.

After completion of the reaction, the phenol biphenylaralkyl resin represented by the general formula (2) can be obtained by removing unreacted phenol by distillation. Since hydrogen halide produced as a by-product is also removed along with the removal of phenol by distillation, the phenol biphenylaralkyl resin obtained by this reaction is used for the reaction with the benzyl halides represented by the general formula (4). preferable.

The phenolic polymer of the above general formula (1) of the present invention is a molding material, various binders, coating materials,
It can be used as a laminated material. In particular, it is useful as an epoxy resin curing agent, and when used as a curing agent in an epoxy resin-based semiconductor encapsulant, an epoxy resin composition having low water absorption, low elastic modulus and low melt viscosity can be obtained.

Examples of the epoxy resin which can be used together with the above-mentioned phenolic polymer of the present invention include bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin and biphenyl type epoxy resin. Resin, phenol biphenyl aralkyl type epoxy resin, epoxide of aralkyl resin by xylylene bond such as phenol and naphthol, dicyclopentadiene type epoxy resin, glycidyl ether type epoxy resin such as dihydroxynaphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl Epoxy resins having two or more epoxy groups in the molecule, such as amine type epoxy resins and halogenated epoxy resins, can be mentioned.
These epoxy resins may be used alone or in combination of two or more.

Upon curing the epoxy resin, it is desirable to use a curing accelerator together. As such a curing accelerator, a known curing accelerator for curing an epoxy resin with a phenol resin-based curing agent can be used. For example, a tertiary amine, a quaternary ammonium salt, an imidazole and its tetraphenylboron salt, An organic phosphine compound and its boron salt, a quaternary phosphonium salt, etc. can be mentioned. More specifically, triethylamine, triethylenediamine, benzyldimethylamine, 2,4
6-tris (dimethylaminomethyl) phenol, 1,
Tertiary amines such as 8-diazabicyclo (5,4,0) undecene-7, 2-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4- Imidazoles such as methylimidazole, organic phosphine compounds such as triphenylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetranaphthoic acid borate, etc. Can be mentioned. Among them, organic phosphine compounds and quaternary phosphonium quaternary borate salts are preferable from the viewpoint of low water absorption and reliability.

If necessary, an inorganic filler, a coupling agent, a mold release agent, a colorant, a flame retardant, a flame retardant aid, a low stress agent, etc. are added to the epoxy resin composition of the present invention or previously added. It can be used by reacting. Also, other curing agents can be used in combination. Examples of such a curing agent include a phenol novolac resin, a phenol aralkyl resin, a phenol biphenyl aralkyl resin, a phenol naphthyl aralkyl resin, a naphthol aralkyl resin, and a triphenol methane type novolac resin.

Especially when used for semiconductor encapsulation, the addition of an inorganic filler is essential. Examples of such inorganic fillers include amorphous silica, crystalline silica, alumina, glass, calcium silicate, gypsum, calcium carbonate, magnesite, clay, talc, mica, magnesia, barium sulfate and the like. However, amorphous silica and crystalline silica are particularly preferable. Further, in order to increase the compounding amount of the filler while maintaining excellent moldability, it is preferable to use a spherical filler having a wide particle size distribution that enables fine packing.

Examples of the coupling agent include vinylsilane-based, aminosilane-based, epoxysilane-based, and other silane-based coupling agents and titanium-based coupling agents, and examples of the release agent include carnauba wax, paraffin wax, and the like.
Examples include stearic acid, montanic acid, a polyolefin wax containing a carboxyl group, and carbon black as a colorant. Examples of flame retardants include halogenated epoxy resins, halogen compounds, phosphorus compounds and the like, and flame retardant aids such as antimony trioxide. Examples of the stress reducing agent include silicone rubber, modified nitrile rubber, modified butadiene rubber, modified silicone oil and the like.

The blending ratio of the phenolic polymer of the present invention to the epoxy resin is, considering heat resistance and mechanical properties,
The hydroxyl group / epoxy group equivalent ratio is preferably 0.5 to 1.5, particularly preferably 0.8 to 1.2. Further, even when it is used in combination with another curing agent, it is preferable that the equivalent ratio of hydroxyl group / epoxy group be the above ratio. The curing accelerator is preferably used in the range of 0.1 to 5 parts by weight with respect to 100 parts by weight of the epoxy resin in consideration of the curing characteristics and various physical properties. Further, in the epoxy resin composition for semiconductor encapsulation, although slightly different depending on the type of the inorganic filler, considering solder heat resistance, moldability (melt viscosity, fluidity), low stress, low water absorption, etc., The inorganic filler is preferably blended in such a proportion that it accounts for 60 to 93% by weight of the entire composition.

As a general method for preparing an epoxy resin composition as a molding material, the respective raw materials in a predetermined ratio are thoroughly mixed by, for example, a mixer, and then subjected to a kneading treatment with a hot roll or a kneader, followed by cooling. After solidification, a method of pulverizing to an appropriate size and forming into a tablet if necessary can be mentioned. The molding material thus obtained can be used for semiconductor encapsulation by, for example, low-pressure transfer molding. Curing of the epoxy resin composition can be performed, for example, in a temperature range of 100 to 250 ° C.

[0053]

[Example] [Example 1] Phenol 9 in a four-necked flask
6.7 g (1.03 mol), 4,4'-dichloromethylbiphenyl 103.3 g (0.41 mol) and water 0.5
After charging g and raising the temperature, the inside of the system became uniform, and after the generation of HCl started, the temperature was maintained at 100 ° C. for 3 hours, and then 15
Heat treatment was applied at 0 ° C. for 1 hour. The HCl generated in the reaction was volatilized out of the system as it was and trapped with alkaline water.
At this stage, unreacted 4,4′-dichloromethylbiphenyl did not remain, and it was confirmed by gas chromatography that all had reacted. After the reaction is completed, the pressure is reduced to remove the unreacted phenol out of the system, and finally at about 4000 Pa for 15
By performing a reduced pressure treatment to 0 ° C., residual phenol was not detected by gas chromatography. The obtained phenolbiphenylaralkyl resin was represented by the general formula (9), had an OH group equivalent of 213 g / eq, and had an average value of c calculated from the OH group equivalent of 2.0.

Subsequently, while maintaining the phenolbiphenylaralkyl resin at 140 ° C., 77.0 g (0.61 mol) of benzyl chloride and 0.5 g of water were added dropwise over 1 hour, and the temperature was maintained for 2 hours. The HCl generated in the reaction was volatilized out of the system as it was and trapped with alkaline water. Thus, 196.8 g of the intended phenolic polymer was obtained. The melt viscosity at 150 ° C. measured by an ICI melt viscometer was 480 mPa · s, and the OH group equivalent determined by the acetylation back titration method was 303 g / eq. The mass spectrum chart is shown in FIG. 1, the proton NMR chart is shown in FIG. 2, the GPC chart is shown in FIG.
A GPC chart of the raw material phenolbiphenylaralkyl resin is shown in FIG. As described above, these data show that the obtained phenolic polymer is represented by the general formula (8), and the average value of c in the formula is 2.
It was found that 0 and (a + bc) / (1 + c) were 1.0.

Example 2 The amount of benzyl chloride used was 5
The same procedure as in Example 1 was carried out except that the amount was changed to 7.7 g (0.46 mol) to obtain 180.2 g of a phenol-based polymer. The melt viscosity at 150 ° C. is 430 mPa · s,
The OH group equivalent was 280 g / eq. Also this GPC
Is shown in FIG. From these data, the obtained phenolic polymer is represented by the general formula (8), and c
Average value is 2.0, (a + bc) / (1 + c) is 0.7
It turned out to be four.

Example 3 A four-necked flask was charged with 130.6 g (1.39 mol) of phenol and 67.8 g (0.28 mol) of 4,4'-dimethoxymethylbiphenyl and heated to 60 ° C. , 1.6 g of paratoluenesulfonic acid monohydrate was added as a 20% aqueous solution,
It was kept at 135 ° C. for 3 hours, and further heat-treated at 150 ° C. for 1 hour. The methanol generated in the reaction was volatilized out of the system as it was, and after cooling, it was trapped. At this stage, unreacted 4,4′-dimethoxymethylbiphenyl did not remain, and it was confirmed by gas chromatography that all had reacted. After completion of the reaction, unreacted phenol was removed to the outside of the system by reducing the pressure, and finally, the pressure was reduced to 140 ° C. at 2660 Pa, whereby residual phenol was not detected by gas chromatography. The obtained phenol biphenyl aralkyl resin was represented by the general formula (9), and the average value of c was 1.3.

While maintaining this phenolbiphenylaralkyl resin at 140 ° C., benzyl alcohol 24.
9 g (0.23 mol) was added dropwise over 1 hour, and another 3
Held for hours. The water coming out from the reaction was volatilized out of the system as it was, and after cooling, it was trapped. In this way, 113.6 g of the intended phenolic polymer was obtained. The melt viscosity at 150 ° C. is 130 mPa · s, and the OH group equivalent is 24
It was 8 g / eq. From these data, the phenolic polymer is represented by the general formula (8), and the average value of c is 1.
3, it was found that (a + bc) / (1 + c) was 0.50.

[Examples 4 to 6] Phenolic polymers and epoxy resins (ESCN manufactured by Sumitomo Chemical Co., Ltd.) obtained in Examples 1 to 3.
-195, orthocresol novolac type, epoxy equivalent 195 g / eq), fused silica, triphenylphosphine, aminosilane coupling agent and carnauba wax were mixed in the proportions shown in Table 2 and thoroughly mixed, then 85
A molding composition was obtained by kneading for 3 minutes with a two-roll roll of ℃ ± 3 ℃, cooling and pulverizing. 175 at a pressure of 100 kgf / cm ² for the molding composition using a transfer molding machine
After molding for 2 minutes at 180 ° C, post cure for 6 hours at 180 ° C for water absorption, flexural modulus and glass transition temperature (T
A test piece for g) was obtained.

The physical properties of these molding materials were measured by the following methods.

(1) Water absorption rate A water absorption rate was measured when a disk having a 50 mm diameter × 3 mm sample shape was allowed to absorb water for 168 hours in an atmosphere of 85 ° C. and a relative humidity of 85% RH.

Water absorption rate (%) = (weight increase after treatment / weight before treatment) × 100 (2) Flexural modulus Sample shape A strip of 80 × 10 × 4 mm was allowed to stand in a 260 ° C. atmosphere for 10 minutes and then JIS Measurement according to K6911 (3) Glass transition temperature (Tg) The linear expansion coefficient was measured by TMA, and the inflection point of the linear expansion coefficient was taken as Tg.

Comparative Example 1 Instead of the phenolic polymers of Examples 1 to 3, a commercially available phenol aralkyl resin (HE10C-10 manufactured by Sumikin Chemical Co., OH group equivalent 168 g /
A molding composition was prepared and evaluated in the same manner except that eq) was used.

Comparative Example 2 Molding was carried out in the same manner except that a commercially available phenol novolac resin (Showa High Polymer Co., Ltd., OH group equivalent 106 g / eq) was used in place of the phenolic polymers of Examples 1 to 3. A composition for use was prepared and evaluated.

The results of these evaluations are also shown in Table 2.

[0065]

[Table 2]

[0066]

According to the present invention, it is possible to provide a phenolic polymer useful as a molding material, various binders, coating materials, laminated materials and the like. Such a phenolic polymer is particularly useful as an epoxy resin curing agent, and particularly when used as a semiconductor encapsulant, forms an epoxy resin composition having low water absorption, low elastic modulus and low melt viscosity. You can

[Brief description of drawings]

FIG. 1 is a mass spectrum chart of the phenolic polymer obtained in Example 1.

2 is a proton NMR chart of the phenolic polymer obtained in Example 1. FIG.

FIG. 3 G of the phenolic polymer obtained in Example 1
It is a PC chart.

FIG. 4 is a GPC chart of a phenol biphenyl aralkyl resin which is a raw material of the phenolic polymer of Example 1.

FIG. 5: G of the phenolic polymer obtained in Example 2
It is a PC chart

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-11-71451 (JP, A) JP-A-2001-64340 (JP, A) JP-A-10-310632 (JP, A) JP-A-8-120039 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 61/00-61/12

Claims (11)

(57) [Claims] 1. A phenolic polymer represented by the general formula (1). [Chemical 1] (In the formula, Ar is an aryl group, R ¹ and R ² are each hydrogen or a methyl group, R ³ , R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms, and a, b and c are: 0 ≦ a ≦
2, 0 ≦ b ≦ 2, 1 ≦ c ≦ 5, (a + bc) / (1+
c) is in the range of 0.2 to 1.5, and c b's are the same or different from each other. ) 2. In the general formula (1), R ¹ , R ² , R
The phenolic polymer according to claim 1, wherein ³ , R ⁴ and R ⁵ are all hydrogen. 3. The phenol according to claim 1, wherein the phenol biphenylaralkyl resin represented by the general formula (2) and the benzyl compound represented by the general formula (3) are reacted in the presence of an acid catalyst. Of producing a base polymer. [Chemical 2] (In the formula, R ³ , R ⁴ and R ⁵ are each hydrogen or carbon 1
~ 4 alkyl groups, c is 1 ≤ c ≤ 5) (In the formula, Ar is an aryl group, R ¹ and R ² are each hydrogen or a methyl group, and R ⁶ is hydrogen or an alkyl group having 1 to 4 carbon atoms) 4. The phenolic system according to claim 1, wherein the phenol biphenylaralkyl resin represented by the general formula (2) and the benzyl halides represented by the general formula (4) are reacted in the presence of water. Method for producing polymer. [Chemical 4] (In the formula, Ar is an aryl group, R ¹ and R ² are each hydrogen or a methyl group, and X is Cl, Br or I). 5. A phenol biphenylaralkyl resin represented by the general formula (2) is obtained by reacting a biphenyl compound represented by the general formula (5) with a phenol represented by the general formula (6) in the presence of an acid catalyst. The method according to claim 3 or 4, which is obtained. [Chemical 5] (In the formula, R is hydrogen or an alkyl group having 1 to 4 carbon atoms,
R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms. (In the formula, R ³ is hydrogen or an alkyl group having 1 to 4 carbon atoms) 6. A phenol biphenyl aralkyl resin represented by the general formula (2) reacts a dihalomethylbiphenyl compound represented by the general formula (7) with a phenol represented by the general formula (6) in the presence of water. The method according to claim 3 or 4, which is obtained by [Chemical 7] (In the formula, X is Cl, Br or I, R ⁴ and R ⁵ are each hydrogen or an alkyl group having 1 to 4 carbon atoms) 7. A curing agent for an epoxy resin, comprising the phenolic polymer according to claim 1 or 2. 8. An epoxy resin composition containing the phenolic polymer according to claim 1 and an epoxy resin. 9. The epoxy resin composition according to claim 8, which contains an inorganic filler. 10. The epoxy resin composition according to claim 8, which is used for semiconductor encapsulation. 11. An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 8.