JP2002275228A - Phenolic polymer, method for producing the same, and curing agent for epoxy resin using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenolic polymer having low melt viscosity, high glass transition temperature, and excellent curing properties, which is suitable as an epoxy resin curing agent for semiconductor encapsulation, printed circuit board insulation, etc. I do. A phenol, a salicylaldehyde and a formaldehyde are reacted in the presence of an acid catalyst, and have a melt viscosity at 150 ° C of 50 to 300 mPa · s.
a phenolic polymer represented by the following formula: H- [CH ((Ph) OH) ((Ph) OH)] _n- [CH _2- (Ph) OH] _m -Ph (OH) (where Ph is a benzene nucleus residue such as phenyl or phenylene) And m / n is 0.7 to 1.5)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to various binders,
The present invention relates to a phenolic polymer useful for a coating material, a laminate, a molding material, and the like, a method for producing the same, and a curing agent for an epoxy resin using the same. Particularly suitable for epoxy curing agents for semiconductor encapsulation, printed circuit board insulation, etc., low melt viscosity,
The present invention relates to a phenolic polymer having both a high glass transition temperature and excellent curing properties, and a method for producing the same.

[0002]

2. Description of the Related Art Various phenolic polymers such as phenol novolak type resins and phenol aralkyl resins have been used as epoxy resin curing agents for electronic materials, particularly for encapsulating semiconductors and for insulating printed boards. However, in recent years, with the miniaturization and thinning of the semiconductor package, the increase in the number of pins, and the high-density mounting, a resin with higher performance has been required.

An important physical property for using a phenolic polymer for a semiconductor encapsulant is a high glass transition temperature. As a means for increasing the glass transition temperature, it is effective to increase the hydroxyl group concentration, and for this reason, a so-called polyfunctional type is often used. A typical example thereof is a triphenolmethane-type phenol resin represented by the following formula (2) (JP-B-7-1219).
79, JP-A-2-173023).

[0004]

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[0005] These triphenolmethane-type phenol resins have a high glass transition temperature and are therefore excellent in various reliability. In addition, BGA (Ball
When used in a single-sided sealed package such as a GridArray, the package has excellent performance in that the package is small in warpage. However, in recent semiconductor packages, for example, in the case of BGA, fine pitch and batch encapsulation are required. In addition to low warpage, high fluidity and good adhesion to the substrate surface are required. ing. Also,
Even in packages such as SOP, QFP, and DIP, low viscosity is strongly desired in terms of elongation of the wire length, reduction of the wire diameter, and miniaturization. If the melt viscosity is low, the fluidity and adhesion are improved, and a large amount of filler can be added, which is advantageous in terms of solder heat resistance and water resistance. That is, in order to satisfy the required properties of these sealing materials, the appearance of a phenolic polymer (curing agent) having both a high glass transition temperature, a low melt viscosity, and good curability is strongly desired.

In addition, the interlayer insulating material of the build-up substrate
An epoxy resin composition having excellent water resistance and good adhesiveness at a high glass transition temperature is desired, and in order to achieve this,
A phenolic curing agent which is originally excellent in water resistance and storage stability and which has both a high glass transition temperature, a low melt viscosity and excellent curability is desired.

[Problems to be solved by the invention]

However, when the concentration of hydroxy groups is increased to increase the glass transition temperature, the melt viscosity increases due to hydrogen bonding between the hydroxy groups. As a result, the fluidity is poor due to an increase in the melt viscosity, which causes molding problems such as wire deformation. When the molecular weight is reduced or the hydroxyl group concentration is reduced to lower the melt viscosity, the glass transition temperature is lowered and the curability at the time of molding is lowered. That is, it is considered that it is theoretically difficult to achieve both a high glass transition temperature, a low melt viscosity, and curability.

A resin in which an allyl group is added to a triphenolmethane-type phenol resin has also been proposed (JP-A-4-23824). These resins have a high glass transition temperature and thus have a small heat shrinkage, and have a large free volume as a resin skeleton, and therefore have a small cure shrinkage, which is said to contribute to low warpage. However, this type of resin is still insufficient to the required level because the glass transition temperature and the curability also decrease as the amount of allyl groups introduced increases.

[0009]

Means for Solving the Problems The present inventors have made use of the excellent physical properties such as high glass transition temperature, low heat shrinkage, and low warpage of the above-mentioned triphenolmethane type phenol resin, and have low melt viscosity and curability. As a result of intensive studies to obtain an excellent phenolic curing agent, the polymer has both a triphenolmethane-type polymer unit and a phenol novolak polymer unit in the molecule, and the ratio of the degree of polymerization of both is in a specific range. As a result, it has been found that a phenolic polymer having a high glass transition temperature, a low melt viscosity and excellent curability can be obtained, and the present invention has been completed.

That is, the present invention is represented by the following general formula (1) and has a melt viscosity at 150 ° C. of 50 to 300 mPa.
S is a phenolic polymer.

Embedded image (Where m / n is 0.7 to 1.5 and R ¹ , R ² , R ³
And R ⁴ are a hydroxy group or an alkyl group, p,
q, r and s are 0-2. )

The present invention also relates to a phenolic compound represented by the above formula (1), wherein phenols, salicylaldehydes and formaldehyde are condensed in the presence of an acid catalyst, and the acid catalyst is removed by a reduced pressure treatment. This is a method for producing a polymer.

Further, the present invention is a curing agent for an epoxy resin comprising the phenolic polymer represented by the above formula (1).

[0013]

DETAILED DESCRIPTION OF THE INVENTION The phenolic polymer of the present invention has the formula
(1) is a copolymerized phenolic polymer having n polymerization units of a triphenolmethane-type resin represented by (n) and m polymerization units of a phenol novolak resin, represented by the formula (1)
In the above, the ratio m / n of the degree of polymerization of each polymerization unit is 0.7 to 1.5, preferably 0.9 to 1.4. The melt viscosity at 150 ° C. is 50 to 300 mPa · s, preferably 50 to 200 mPa · s.
mPa · s. As those having such a melt viscosity, the polymerization degree n and m of each polymerization unit is usually a mixture of polymers having 0 to 10 and the average polymerization degree is 0.6 to 2.0, preferably 0.8 to 1.4. Can be

When the degree of polymerization is high and the melt viscosity is higher than the above range, the fluidity decreases. Further, those having a lower molecular weight and a lower melt viscosity are not preferred because the glass transition temperature becomes lower.

Incidentally, JP-A-63-22824 discloses that
It describes a copolymer of a triphenolmethane resin and a phenol novolak resin, but does not disclose a copolymer having a low melt viscosity as in the present invention. Particularly under polymerization conditions as shown as specific examples, the degree of polymerization is large, and the melt viscosity at 150 ° C. is 300 mPa ·
Only a resin that greatly exceeds s is obtained, and does not achieve the object of the present invention.

In the phenolic polymer of the present invention, when m / n exceeds 1.5, the glass transition temperature decreases and the curing rate decreases. On the other hand, if m / n is less than 0.7, the melt viscosity increases and the fluidity deteriorates.

The phenolic polymer of the present invention represented by the formula (1) can be prepared according to the types of R ¹ , R ² , R ³ and R ^{4 in} the formula (1) depending on the types of the starting phenols and salicylaldehydes. Although various numbers are obtained, the average number of substituted hydroxy groups per phenyl group is 1.0 to 1.6. Also, p, q, r, and s are 0 to 2, but when phenol and salicylaldehyde are used as raw materials, p = q
= R = s = 0, that is, the following equation (3) is obtained.

[0018]

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The phenolic polymer of the present invention has a structure in which polymerized units of a triphenolmethane type resin and a phenol novolak resin are both present in a molecule at a specific ratio.
As a result, a polymer suitable for an epoxy curing agent and having a low melt viscosity, a high glass transition temperature, and excellent curing properties is obtained.

The phenolic polymer of the present invention can be widely used for applications such as binders, coating materials, laminates, molding materials, etc., especially when it has a low melt viscosity, a high glass transition temperature and excellent curing properties. Therefore, it is particularly suitable for epoxy curing agents for semiconductor encapsulation, printed circuit board insulation, and the like.

[Production of phenolic polymer] The phenolic polymer represented by the above formula (1) used in the present invention is exemplified by a case where phenol is used as phenol and salicylaldehyde is used as salicylaldehyde. And phenol, salicylaldehyde and formaldehyde by condensation in the presence of an acid catalyst according to the following formula (4).

[0022]

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The condensation reaction can be carried out in a single step by adding salicylaldehyde and formaldehyde simultaneously as shown in the formula (4). It is used in an amount of 0 mol or more, preferably in the range of 3.3 to 10.0 mol, and the reaction between phenol and formaldehyde is preferentially performed by lowering the reaction temperature to form a low molecular weight phenol novolak resin. It is necessary to adopt a method in which the phenol novolak resin, salicylaldehyde and phenol are reacted by raising the temperature or increasing the amount of the catalyst. If the above reaction conditions are deviated, for example, the amount of phenol used is less than 3.0 moles per 1 mole of salicylaldehyde and formaldehyde, only phenolic polymers having a high molecular weight and a high melt viscosity can be obtained.

The phenolic polymer is also obtained by condensing phenol and formaldehyde in the presence of an acid catalyst to form a phenol novolak resin in advance, as shown in formula (5), and then adding salicylaldehyde according to formula (6). And
It can also be carried out by a two-stage reaction in which condensation is carried out in the presence of an acid catalyst. In such a two-stage reaction, phenol can be newly added in the second-stage reaction. In this case as well, it is important to use an excess of phenol as in the case of the single-stage reaction. For example, in the first-stage reaction, phenols are added in an amount of 2.5 mol per mol of formaldehyde.
Mole, preferably 3.3 to 10.0 moles,
The salicylaldehyde and phenol to be added in the second-stage reaction are 3.0 mol or more of phenol to be charged in a total of 1 to 2 stages per 1 mol of salicylaldehyde and formaldehyde to be charged in a total of 1 to 2 stages. It is important to use it in the range of preferably 3.3 to 10.0 mol. When the reaction is carried out in such a two-stage reaction, the degree of polymerization of each polymerization unit of the triphenolmethane-type resin and the phenol novolak resin, that is, the distribution of n and m becomes narrow, the control of the molecular weight becomes easy, and the weight of the desired melt viscosity becomes heavy. It is preferable for the purpose of the present invention, since coalescence is easily obtained.

[0025]

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[0026]

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In the production of the phenolic polymer of the present invention, the amounts of phenols, salicylaldehydes and formaldehyde used as raw materials are controlled and
By setting the reaction conditions as described above,
Melt viscosity at 50 ° C. and polymerization degree ratio m /
A polymer having n can be obtained. The amount of the acid catalyst used in the one-stage reaction and the two-stage reaction varies depending on the type of the acid catalyst. %, And in the case of trifluoromethanesulfonic acid, 0.002 to 0.1%.
It is preferable to use about 01% by weight. In particular, when performing a two-stage reaction, when reacting salicylaldehydes in the second stage with phenols and phenol novolak resin,
It is preferable to use hydrochloric acid or trifluoromethanesulfonic acid. The reaction temperature is not particularly limited, but may be 60
It is preferable to set the temperature in the range of about to 100 ° C.

After condensing phenols, formaldehyde and salicylaldehyde in the presence of an acid catalyst, the unreacted phenols and acid catalyst are removed.
The phenolic polymer of the present invention can be obtained. The method of removing phenols is generally a method in which heat is applied under reduced pressure or while blowing an inert gas to distill phenols out of the system. There is also a method of removing the acid catalyst by washing such as water washing.However, when a volatile acid is used, a method of removing it out of the system by distillation together with phenols shortens the reaction process and increases the pot efficiency. This is preferable in that respect.

Examples of phenols include phenol,
Cresol, ethyl phenol, propyl phenol,
In addition to monohydric phenols such as butylphenol, hexylphenol, nonylphenol, xylenol, and butylmethylphenol, dihydric phenols such as catechol, resorcin and hydroquinone can be used, and phenol is particularly preferred.

As salicylaldehydes, besides salicylaldehyde, alkyl-substituted salicylaldehydes and the like can be used, and it is particularly preferable to use salicylaldehyde. Also, it can be used in combination with p-hydroxybenzaldehyde.

Further, as formaldehyde, 37%
Aqueous formaldehyde solution and paraformaldehyde,
A polymer that is decomposed into formaldehyde in the presence of an acid such as trioxane can be used.

The number of hydroxy groups substituted for each phenyl group in the formula (1) can be adjusted depending on the types of the phenols and salicylaldehydes used as raw materials. The average number of substituted hydroxy groups per group is 1.0 to 1.6, preferably 1.0 to 1.4. When phenol and salicylaldehyde are used as raw materials, p, q, r, and s are all 0 and phenyl group The average number of substituted hydroxy groups per unit is 1.

The acid catalyst is not particularly limited, and known catalysts such as hydrochloric acid, oxalic acid, trifluoromethanesulfonic acid, sulfuric acid, phosphoric acid, and paratoluenesulfonic acid can be used alone or in combination of two or more. Hydrochloric acid, oxalic acid or trifluoromethanesulfonic acid is particularly preferred. These catalysts have a high catalytic activity, and the catalyst can be removed together with unreacted phenol, salicylaldehyde, and formaldehyde by decompression treatment after completion of the reaction, so that a washing step such as washing with water is unnecessary.

[Epoxy Resin Cured Product] The phenolic polymer of the present invention can be used as a curing agent for epoxy resins. The epoxy resin cured product is obtained by mixing a phenolic polymer, an epoxy resin and a curing accelerator, and
It is obtained by curing in a temperature range of ° C.

Examples of the epoxy resin include glycidyl ether type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolak type epoxy resin, phenol novolak type epoxy resin, triphenolmethane type epoxy resin and biphenyl type epoxy resin. Epoxy resins having two or more epoxy groups in the molecule, such as resins, glycidyl ester type epoxy resins, glycidylamine type epoxy resins, and halogenated epoxy resins, are exemplified. These epoxy resins may be used alone or in combination of two or more.

(Curing Accelerator) As a curing accelerator, a known curing accelerator for curing an epoxy resin with a phenolic curing agent can be used. Examples of such curing accelerators include organic phosphine compounds and their boron salts, tertiary amines, quaternary ammonium salts, imidazoles and their tetraphenylboron salts, and among them, curability and moisture resistance In view of this, triphenylphosphine and 1,8-diazabicyclo (5,4,0) undecene-7 (DBU) are preferred.
Further, in order to obtain higher fluidity, a heat latent curing accelerator which exhibits activity by heating is more preferable, and a tetraphenylphosphonium derivative such as tetraphenylphosphonium / tetraphenylborate is preferable.

(Other Additives) In the epoxy resin composition of the present invention, if necessary, an inorganic filler, a releasing agent, a coloring agent, a flame retardant, a low stress agent, etc. are added or used in advance. be able to. In particular, 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 can be mentioned, and amorphous silica and crystalline silica are particularly preferable. The amounts of these additives used may be the same as the amounts used in conventional epoxy resin compositions for semiconductor encapsulation.

The triphenolmethane type resin of the present invention has an appropriate amount of phenol novolak resin units, and when used as an epoxy resin curing agent, maintains excellent curing characteristics such as a high glass transition temperature and has a low viscosity. Can be realized.

[0039]

EXAMPLES The present invention will be specifically described below with reference to examples. The methods for measuring the physical properties of the phenolic polymer obtained in the present invention are described in (1) and (2), and an epoxy resin composition containing a phenolic polymer as a curing agent (phenolic polymer, epoxy resin, inorganic filler) , A composition comprising a curing accelerator, a silane coupling agent, and carnauba wax)
Are shown in (3) to (5).

(1) Melt Viscosity at 150 ° C. The melt viscosity of the phenolic polymer at 150 ° C. was measured using an ICI melt viscometer.

(2) Polymerization degree ratio m / n The reaction rate of formaldehyde and salicylaldehyde was determined, and the ratio of methylene bond / methine bond (m / n) in the polymer was determined from the charged amount and the reaction rate. The formaldehyde conversion was determined by measuring formaldehyde remaining after the reaction by the hydroxylamine hydrochloride method. The conversion of salicylaldehyde was determined by measuring the remaining salicylaldehyde after the reaction by gas chromatography.

(3) Curatometer Curing Torque For an epoxy resin composition containing a phenolic polymer as a curing agent, the speed of torque rise by curing at 175 ° C. was measured with a curast meter, and the torque of 60 seconds and 90 seconds was measured. Was read.

(4) Glass transition temperature An epoxy resin composition containing a phenolic polymer as a curing agent was heated to 175 ° C.-12 using a transfer molding machine.
After molding in 0 seconds, a test piece of an appropriate size was cut out from a molded article post-cured at 180 ° C. for 6 hours, and TMA was cut out.
The glass transition temperature was measured by the method (heating rate 5 ° C./min).

(5) Melt Viscosity The minimum melt viscosity at 175 ° C. of the epoxy resin composition containing a phenolic polymer as a curing agent was determined by a flow tester method (load: 20 kgf / cm ² , nozzle: 1 × ² L).
mm).

Example 1 In a glass reactor equipped with a stirrer, a condenser and a nitrogen gas inlet tube, 94 g (1 mol) of phenol and a 19.5% aqueous 37% formalin solution were used.
g (0.24 mol in terms of formaldehyde) and 0.34 g of oxalic acid dihydrate were charged and reacted at 95 ° C. for 4 hours.

Thereafter, 106.2 g of phenol was further added.
(1.13 mol), 29.3 g of salicylaldehyde
(0.24 mol) and 7.1 g of 35% hydrochloric acid aqueous solution were additionally charged and reacted at 90 ° C. for 4 hours. Unreacted formaldehyde and salicylaldehyde were not detected in the condensed liquid after the reaction (reaction rate: 100%).

The condensed liquid was further heat-treated under reduced pressure to remove unreacted phenol, water, oxalic acid and HCl out of the system, thereby obtaining 98.0 g of a phenol polymer.

Raw material charge ratio: phenol is 4.4 mole times the sum of salicylaldehyde and formaldehyde. Properties of Produced Phenolic Polymer Hydroxyl Equivalent: 100 g / eq 150 ° C. Melt Viscosity: 220 mPa · s m / n: 1.0 (Value Obtained from Reaction Rate of Aldehydes) [Example 2] Stirrer, condenser, and In a glass reactor equipped with a nitrogen gas inlet tube, 94 g of phenol (1
Mol), 14.6 g of a 37% aqueous formalin solution (0.18 mol in terms of formaldehyde), 0.33 of oxalic acid dihydrate
g was charged and reacted at 95 ° C. for 4 hours.

Thereafter, 17.4 g of phenol was further added.
(0.19 mol), 16.9 g of salicylaldehyde
(0.14 mol) and 4.1 g of a 35% hydrochloric acid aqueous solution were additionally charged and reacted at 90 ° C. for 5 hours. Unreacted formaldehyde and salicylaldehyde were not detected in the condensed liquid after the reaction (reaction rate: 100%).

The condensed liquid was further heat-treated under reduced pressure to remove unreacted phenol, water, oxalic acid and HCl out of the system, thereby obtaining 64.3 g of a phenol polymer.

Raw material charge ratio: 3.72 mol times of phenol based on the sum of salicylaldehyde and formaldehyde. Properties of generated phenolic polymer Hydroxyl equivalent: 101 g / eq 150 ° C. Melt viscosity: 180 mPa · s m / n: 1.3 (value obtained from the reaction rate of aldehydes)

Example 3 85% of 10% trifluoromethanesulfonic acid was used instead of 4.1 g of 35% hydrochloric acid aqueous solution.
The same processing as in Example 2 was performed except that g was used.
2.1 g of a phenolic polymer was obtained.

Raw material charge ratio: 3.72 mol times of phenol with respect to the sum of salicylaldehyde and formaldehyde. Properties of Produced Phenolic Polymer Hydroxyl Equivalent: 101 g / eq 150 ° C. Melt Viscosity: 210 mPa · s m / n: 1.3 (Value Obtained from Reaction Rate of Aldehydes) [Comparative Example 1] In the glass reactor used,
94 g (1 mol) of phenol, 19.5 g of a 37% aqueous solution of formalin (0.24 mol in terms of formaldehyde),
0.34 g of oxalic acid dihydrate was charged and reacted at 95 ° C. for 4 hours.

Thereafter, 35.7 g of phenol was further added.
(0.38 mol), 14.7 g of salicylaldehyde
(0.12 mol) and 4.7 g of a 35% hydrochloric acid aqueous solution were additionally charged and reacted at 90 ° C. for 4 hours. Unreacted formaldehyde and salicylaldehyde were not detected in the condensed liquid after the reaction (reaction rate: 100%).

The condensed liquid was further heat-treated under reduced pressure to remove unreacted phenol, water, oxalic acid and HCl out of the system to obtain 70.5 g of a phenol polymer.

Raw material charge ratio: phenol is 3.8 mole times the sum of salicylaldehyde and formaldehyde. Properties of Produced Phenol Polymer Hydroxyl equivalent: 100 g / eq 150 ° C. Melt viscosity: 190 mPa · s m / n: 2.0 (value obtained from the reaction rate of aldehydes) [Comparative Example 2] In Examples 1 to 3, In the glass reactor used,
Phenol 94 g (1 mol), 37% formalin aqueous solution 16.2 g (0.20 mol in terms of formaldehyde),
0.33 g of oxalic acid dihydrate was charged and reacted at 95 ° C. for 4 hours.

Thereafter, 162.4 g of phenol was further added.
(1.73 mol), 48.8 g of salicylaldehyde
(0.40 mol) and 9.2 g of 35% hydrochloric acid aqueous solution were additionally charged and reacted at 90 ° C. for 4 hours. Unreacted formaldehyde and salicylaldehyde were not detected in the condensed liquid after the reaction (reaction rate: 100%).

The condensed solution was further heat-treated under reduced pressure to remove unreacted phenol, water, oxalic acid and HCl out of the system, thereby obtaining 122.1 g of a phenol polymer.

Raw material charging ratio: phenol is 4.55 mole times the total of salicylaldehyde and formaldehyde. Properties of generated phenolic polymer Hydroxyl equivalent: 99 g / eq 150 ° C. Melt viscosity: 520 mPa · s m / n: 0.5 (value obtained from the reaction rate of aldehydes)

Comparative Example 3 Into the glass reactors used in Examples 1 to 3, 94 g (1 mol) of phenol and 16.2 g of a 37% aqueous solution of formalin (0.1% in terms of formaldehyde).
20 mol), 24.4 g (0.20 salicylaldehyde)
Mol) and 0.4 g of 97% sulfuric acid at the same time.
Allowed to react for hours. Unreacted formaldehyde and salicylaldehyde were not detected in the condensed liquid after the reaction (reaction rate: 100%).

The condensed liquid was neutralized with NaOH to obtain pure 1
After adding 00 g and washing with water, the organic phase was further distilled under reduced pressure to remove unreacted phenol out of the system, thereby obtaining 63 g of a phenol polymer.

Raw material charge ratio: phenol is 2.5 mole times the sum of salicylaldehyde and formaldehyde. Properties of generated phenolic polymer Hydroxyl equivalent: 99 g / eq 150 ° C. Melt viscosity: 730 mPa · s m / n: 1.0 (value obtained from the reaction rate of aldehydes)

[Examples 4 to 6, Comparative Examples 4 to 6] Epoxy resin compositions were produced at the compounding ratios shown in Table 1. The compounding method was as follows: kneading was carried out at 80 to 90 ° C. for 4 minutes using a roll kneader, followed by cooling and pulverization to obtain an epoxy resin composition.
The epoxy resin used was an orthocresol type epoxy resin (ESCN195XL manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 193 g / eq).

[0064]

[Table 1]

As is clear from Table 1, the phenolic polymers obtained in Examples 1 to 3 have all of low melt viscosity, high glass transition temperature, and fast curability. In contrast, Comparative Example 1 was inferior in curability, and Comparative Example 2
Is inferior in terms of curability and melt viscosity, and that of Comparative Example 3 is inferior in melt viscosity.

[0066]

The phenolic polymer of the present invention has both polymerized units of triphenolmethane type resin and phenol novolak resin in the molecule, and the degree of polymerization of both and the ratio of the degree of polymerization of both are within a specific range. By having a certain structure,
It is a polymer suitable for epoxy curing agents, having low melt viscosity, high glass transition temperature, and excellent curing properties. This makes it possible to take advantage of the characteristics of triphenolmethane-type phenolic resins such as high glass transition temperature, low heat shrinkage, and rapid curing, and to solve the problem of high melt viscosity, which was a drawback of triphenolmethane-type resins. did it. This makes it possible to cope with the latest semiconductor encapsulating materials such as BGA, and can be used as an epoxy curing agent.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kunio Ichihara 3rd Oki Hikari, Kashima City, Ibaraki Pref. Sumikin Chemical Co., Ltd. (72) Inventor Kiyotaka Murata 3rd Oki Hikari, Kashima City Ibaraki Pref. In-house F term (reference) 4J033 AA01 CA01 CA02 CB03 CB14 CB16 CC03 CC08 CC11 CC12 CD02 HA14 HB03 HB06 4J036 AA01 AB02 AD07 AD08 AF06 AF08 AG00 AH00 DC02 DC40 DC46 DD07 FB08 JA07 JA08

Claims (7)

[Claims] 1. A compound represented by the following general formula (1):
A phenolic polymer having a melt viscosity of 50 to 300 mPa · s. Embedded image (Where m / n is 0.7 to 1.5 and R ¹ , R ² , R ³
And R ⁴ are a hydroxy group or an alkyl group, p,
q, r and s are 0-2. ) 2. The phenolic polymer according to claim 1, wherein p = q = r = s = 0. 3. Condensation of phenols, salicylaldehydes and formaldehyde in the presence of an acid catalyst at a ratio of not less than 3.0 mols of phenols to 1 mol of salicylaldehydes and formaldehyde in total, and reducing the acid catalyst by reduced pressure treatment. The method for producing a phenolic polymer according to claim 1, wherein the phenolic polymer is removed. 4. A phenol and formaldehyde are condensed in the presence of an acid catalyst to form a phenol novolak resin in advance, and then salicylaldehyde is added.
The method for producing a phenolic polymer according to claim 3, wherein the condensation is carried out in the presence of an acid catalyst, and the acid catalyst is removed by a reduced pressure treatment. 5. The method for producing a phenolic polymer according to claim 3, wherein formaldehyde is used in a ratio of 0.7 to 1.5 mol per mol of salicylaldehyde. 6. The method according to claim 3, wherein the acid catalyst is hydrochloric acid, oxalic acid or trifluoromethanesulfonic acid.
The method for producing a phenolic polymer according to any one of the above. 7. A curing agent for an epoxy resin comprising the phenolic polymer according to claim 1 or 2.