JP2000234008A - Phenolic polymer and epoxy resin curing agent using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a phenolic polymer having a low melt viscosity and a high glass transition temperature and being capable of being used as an epoxy curing agent by etherifying a specified proportion of the hydroxyl groups of a triphenylmethane type resin having a specified structure. SOLUTION: A partially etherified phenolic polymer is obtained by etherifying 5-50 mol% hydroxyl groups of a triphenylmethane type resin obtained by condensing a phenol with an aromatic carbonyl compound in the presence of an acidic catalyst and represented by the formula (wherein (n) is 0-4; (a), (b), (c), (d), and (e) are each 0-2; and the average of the substituted hydroxyl groups is 0.5-2.0 per phenyl). The partial esterification consists of dissolving a triphenylmethane resin in an organic solvent such as an alcohol, adding a base to the solution, adding an alkenically, allylically, or otherwise unsaturated halohydrocarbon to the mixture, and reacting the reaction mixture to obtain an alkenyl ether, an allyl ether or the like.

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, and a curing agent for an epoxy resin using the same. In particular, the present invention relates to a phenolic polymer having a low melt viscosity, a high glass transition temperature, and excellent curing properties, which is suitable for an epoxy curing agent for semiconductor encapsulation and for insulating printed boards.

[0002]

2. Description of the Related Art In recent years, as semiconductor packages have become smaller and thinner, have more pins, and have been mounted at higher density, a pin insertion method (D
IP) to surface mounting (SOP, QFP), and more recently BGA (Ball Grid).
New package forms such as Array) have also appeared. The BGA has features such as a wider pitch interval, a smaller package size, and less mounting defects than a QFP having the same number of pins, and it is considered that the transition from the QFP will proceed rapidly in the future.

[0003] BGA is different from conventional QFP and SOP,
The chip is mounted on an organic substrate such as epoxy resin or BT resin, and only one surface is sealed with resin.
Therefore, warpage is likely to occur due to the difference in thermal shrinkage between the substrate and the sealing material. There are also differences from conventional packages, such as a longer bonding wire and a substrate surface covered with a solder resist than QFP or SOP.

[0004] Therefore, a sealing material for BGA is required to have a small warpage, a high fluidity (small wire deformation), and a good adhesion to the substrate surface. In order to satisfy the required properties of these sealing materials, the appearance of a phenolic resin (curing agent) having both a high glass transition temperature and a low melt viscosity is strongly desired. If the glass transition temperature is high, the warpage is small, and 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.

[0005] Also, 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 has both a high glass transition temperature and a low melt viscosity is desired.

[Problems to be solved by the invention]

In general, when the concentration of hydroxy groups is increased in order to increase the glass transition temperature, the melt viscosity increases due to hydrogen bonding between the hydroxy groups. That is, in reality, it was difficult in principle to achieve both a high glass transition temperature and a low melt viscosity.

As a phenolic curing agent to solve this problem, a method of making the main chain of the molecule rigid without relying on the crosslink density (for example, “thermosetting resin” Vol. 15, No. 3,
20 (1994) using a naphthol-based resin) and a method of suspending a bulky structure in the main chain in a pendant manner (JP-A-6-184258). It was unsatisfactory in increasing the transition temperature.

As the phenolic curing agent used in the sealing material for BGA, a phenolic curing agent having a high hydroxyl group concentration in order to raise the glass transition temperature, that is, a so-called polyfunctional type is used.
A typical example is a phenol resin of the triphenolmethane type (Japanese Patent Publication No. 7-121979;
-173023).

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, on the other hand, has a problem that the melt viscosity is high due to the hydrogen bond of the hydroxyl group due to the high hydroxyl group concentration.

[0010]

Means for Solving the Problems The present inventors make use of the excellent physical properties such as high glass transition temperature, low heat shrinkage and low warpage of the above-mentioned triphenolmethane type phenolic resin, and have a low melt viscosity phenolic resin. As a result of intensive studies to obtain a curing agent, a phenolic polymer with a low melt viscosity and a high glass transition temperature can be obtained by partially etherifying the hydroxy group of a triphenylmethane type resin having a specific structure. And completed the present invention.

That is, the present invention is a partially etherified phenolic polymer in which 5 to 50 mol% of hydroxy groups of the triphenylmethane type resin represented by the formula (1) are etherified.

[0012]

Embedded image In the formula, n is 0 to 4, the number of hydroxy groups substituted on one benzene nucleus, a, b, c, d and e are 0 to 2, and the average number of substituted hydroxy groups per phenyl group Is from 0.5 to 2.0.

Further, the present invention is a curing agent for an epoxy resin comprising the above partially etherified phenolic polymer.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Production of triphenylmethane type resin] The triphenylmethane type resin represented by the above formula (1) used in the present invention is obtained by condensing a phenol and an aromatic carbonyl compound group in the presence of an acidic catalyst. Can be obtained by a known method.

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 the aromatic carbonyl compound, for example,
Examples include benzaldehyde, hydroxybenzaldehyde, dihydroxybenzaldehyde, methylhydroxybenzaldehyde, methoxybenzaldehyde and the like.
Of these, hydroxybenzaldehyde is particularly preferred.

The number of hydroxy groups to be substituted for each phenyl group in the formula (1) can be adjusted depending on the types of the phenols and aromatic carbonyl compounds used as raw materials. The average number of substituted hydroxy groups per phenyl group, ie [a + b + n (c + d) + e] / (2n + 3)
Is 0.5 to 2.0, preferably 0.8 to 1.2.

The condensation reaction between the phenol and the aromatic carbonyl compound is carried out using a known acidic catalyst. Examples of the acidic catalyst include hydrochloric acid, sulfuric acid, and paratoluenesulfonic acid.

After performing the above condensation reaction, unreacted substances are removed by concentration under reduced pressure or steam distillation to obtain a condensate.

[Production of allyl etherified triphenylmethane type resin] The partially etherified phenolic polymer of the present invention is obtained by converting the hydroxy group (-OH) of the triphenylmethane type resin represented by the formula (1) into a chain. It is partially etherified with a hydrocarbon group (-R) to form an alkoxy group (-OR). Here, R is a chain hydrocarbon group such as an alkenyl group and an alkyl group, and examples thereof include an unsaturated chain hydrocarbon group such as an alkenyl group and an alkyl group such as a methyl group, an ethyl group, a propyl group, and a butyl group. Of which allyl, butenyl, phenylpropenyl, and
An etherified product by an alkenyl group such as -ethyl-2-propenyl group, particularly an allyl group is preferred. In particular, the partially etherified phenolic polymer used as a curing agent for an epoxy resin is preferably a partially etherified product of an unsaturated chain hydrocarbon group such as an allyl group.

The method for partial etherification of the triphenylmethane type resin can be obtained by a known method for allylating phenols.

That is, after dissolving a triphenylmethane type resin serving as a base resin in an organic solvent, a base is added, and then a halogenated hydrocarbon, for example, allyl chloride, allyl bromide, allyl iodide or the like is added. It can be produced by reacting at 100 ° C. for 1 to 5 hours.

The organic solvent used herein includes alcohols such as methanol, ethanol, n-propanol and n-butanol; ketones such as acetone and methyl ethyl ketone; aprotic polar compounds such as dimethyl sulfoxide and N, N-dimethylformamide. Solvents. The organic solvent may be changed according to the intended use of the resin to be obtained, so that the triphenylmethane type resin and the reaction product are soluble, and the organic solvent itself is not decomposed by the base, and is used if the reaction does not occur. can do. Preferably, alcohols are used.

Examples of the base include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkali carbonates such as potassium carbonate and sodium carbonate. The amount of the phenolic hydroxyl group to be allyletherified is preferably equimolar to the phenolic hydroxy group. The amount of the halogenated hydrocarbon used is at least equivalent to the base.

The etherified phenolic polymer of the present invention is characterized in that the hydroxyl group of the triphenylmethane type resin is 5 to 5
0 mol%, preferably 10 to 25 mol% is a partially etherified product which is etherified, and by maintaining the etherification ratio within this range, a low melt viscosity, a high glass transition temperature, A polymer having excellent curing properties is obtained. If the etherification rate is less than 5 mol%,
High melt viscosity and poor workability. On the other hand, if it exceeds 50 mol%, the glass transition temperature is low and the gelation time is long, and the curing properties are poor.

The partially etherified phenolic polymer of the present invention can be widely used for applications such as binders, coating materials, laminates and molding materials. Etherified phenolic polymer has low melt viscosity, high glass transition temperature,
Since it has excellent curing properties, it is particularly suitable as an epoxy curing agent for semiconductor encapsulation, printed circuit board insulation, and the like.

[Epoxy resin cured product] The epoxy resin cured product is obtained by mixing the above-mentioned etherified triphenylmethane type resin with a partially unsaturated hydrocarbon group, an epoxy resin and a curing accelerator, and curing at a temperature of 100 to 250 ° C. It can be obtained by:

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 and biphenyl type epoxy resin, and glycidyl ester type epoxy resin. And epoxy resins having two or more epoxy groups in the molecule, such as glycidylamine type epoxy resins and halogenated epoxy resins. These epoxy resins may be used alone or in combination of two or more.

Since the partially etherified triphenylmethane type resin of the present invention is partially etherified and has an appropriate proportion of hydroxy groups, when used as an epoxy resin curing agent, a high glass Transition temperature,
Excellent curing characteristics can be maintained, and lower viscosity can be realized. In this case, 1 of the cured product with the epoxy resin
An example is shown by the following equation (2).

[0030]

Embedded image (In the formula, n = 0 to 4, R represents a chain hydrocarbon group.)

In the case of a triphenylmethane resin partially etherified with an unsaturated hydrocarbon group such as an allyl group, the allyl group partially becomes aromatic under the curing reaction conditions (particularly post-curing conditions) with an epoxy resin. The hydroxy group is regenerated by rearrangement, and further reacts with the epoxy group to obtain a cured epoxy resin having a structure such as the formula (3). As a result, a high glass transition temperature is maintained without lowering the crosslink density.

[0032]

Embedded image (In the formula, n = 0 to 4, R represents an alkenyl group.)

[0033]

EXAMPLES The present invention will be specifically described below with reference to examples. The measurement of physical properties of the partially etherified phenol resin obtained in the present invention is as follows.

(1) Degree of etherification The degree of etherification of the resin was determined by measuring the hydroxy group equivalent by an acetylation method.

(2) Melt Viscosity The melt viscosity of the resin was measured using an ICI cone & plate type viscometer (manufactured by Research Equipment: London).
It was measured at 50 ° C.

(3) Gelation time The resin was mixed with a cresol novolak type epoxy resin at an equivalent ratio of 1: 1 and triphenylphosphine as a curing accelerator was mixed with 1 phr, and the mixture was measured at 175 ° C. by a stroke cure method.

(4) Glass transition temperature (Tg) The mixture of (3) was cured at 180 ° C. for 6 hours, and the coefficient of linear expansion was measured by a thermomechanical analysis (TMA) method using TMA8310 manufactured by Rigaku Corporation. .

[Production Example A] (Production of triphenylmethane type resin) In a glass reactor equipped with a stirrer, a condenser and a nitrogen gas inlet tube, 885 g of phenol, 115 g of salicylaldehyde (o-hydroxybenzaldehyde),
10 g of 36% hydrochloric acid was added, the temperature was raised while stirring under a nitrogen stream, and the reaction was carried out at 110 ° C. for 3 hours. Thereafter, vacuum distillation was performed to remove unreacted phenol and salicylaldehyde, thereby obtaining a triphenylmethane type resin.

[Production Example B] 3,4
Using dihydroxybenzaldehyde and benzaldehyde, 3,4 dihydroxybenzaldehyde / phenol condensate and benzaldehyde / phenol condensate were synthesized in the same manner as in Production Example A, and both were mixed at a ratio of 55:45 (weight ratio). A mold resin mixture was obtained.

Table 1 shows the physical properties of the triphenylmethane type resins obtained in Production Examples A and B.

[0041]

[Table 1] SA: salicylaldehyde DHBA: dihydroxybenzaldehyde BA: benzaldehyde

[Production Example C] (Production of phenol aralkyl resin) To the reaction vessel used in Production Example A, 175 g of 1,4-di (chloromethyl) benzene and 188 g of phenol were added, and the mixture was stirred and stirred under a nitrogen stream. The mixture was heated and reacted at 120 ° C. for 2 hours. The temperature was further raised to 150 ° C. and the reaction was performed for 2 hours. The hydrogen chloride generated at this time was removed by trapping with an aqueous sodium hydroxide solution. Then, 0.1% aqueous solution of 1,8-diazabicyclo (5,4,0) undecene was added to 0.1% aqueous solution.
g was added and distillation was performed under reduced pressure to remove unreacted phenol to obtain the desired product. The obtained phenol aralkyl resin is
The melt viscosity at 150 ° C. was 3.6 poise, and the OH group equivalent was 175 g / eq.

[Example 1] (20% allyl etherified triphenylmethane resin) In a glass reactor equipped with a stirrer, a condenser and a dropping funnel, 100 g of the triphenylmethane type resin obtained in Production Example A, methanol 300 g was charged and dissolved, 11.2 g (NET) of potassium hydroxide was added, and the mixture was stirred until it became uniform. After adding 19.1 g of allyl chloride dropwise over 15 minutes, the mixture was stirred at 40 ° C. for 1 hour, and further heated and stirred at 65 ° C. for 5 hours to complete the allyl etherification reaction. Next, the reaction solution was filtered to remove by-produced potassium chloride, and then methanol was removed. The residue was dissolved in methyl isobutyl ketone, washed with pure water, and the methyl isobutyl ketone was removed to obtain an allyl etherified triphenylmethane resin. The etherification rate was 20 mol%. The melt viscosity at 150 ° C., the glass transition point, and the gelation time of this allyl etherified product were measured. Table 2 shows the results.

[Example 2] (10% allyl etherified triphenylmethane resin) 60.6 g of the triphenylmethane type resin obtained in Production Example A and 300 g of methanol were charged and dissolved in the reactor used in Example 1. Then, 5.6 g of potassium hydroxide was added and the mixture was stirred until it became uniform. After 9.6 g of allyl chloride was added dropwise over 15 minutes, the mixture was stirred at 40 ° C. for 1 hour, and further heated and stirred at 65 ° C. for 5 hours to complete the allyl etherification reaction. Next, the reaction solution was filtered to remove by-produced potassium chloride, and then methanol was removed. The residue was dissolved in methyl isobutyl ketone, washed with pure water, and the methyl isobutyl ketone was removed to obtain an allyl etherified triphenylmethane resin having an etherification rate of 10 mol%. Physical properties of this etherified product were measured in the same manner as in the examples. Table 2 shows the results.

[Example 3] (20% methyl etherified triphenylmethane resin) Into the reactor used in Example 1, 100 g of the triphenylmethane type resin obtained in Production Example A and 300 g of methanol were charged and dissolved. 11.2 g (NET) of potassium oxide was added and the mixture was stirred until it became uniform. This is followed by methyl iodide 35.5
g was added dropwise over 15 minutes, and the mixture was stirred at 40 ° C. for 1 hour and further heated and stirred at 65 ° C. for 5 hours to complete the methyl etherification reaction. Next, the reaction solution was filtered to remove by-produced potassium chloride, and then methanol was removed. The residue was dissolved in methyl isobutyl ketone, washed with pure water, and the methyl isobutyl ketone was removed to obtain a methyl etherified triphenylmethane type resin (etherification ratio: 20%). The properties of the etherified product were measured in the same manner as in Example 1. Table 2 shows the results.

[Example 4] (20% allyl etherified triphenylmethane resin) Into the reactor used in Example 1, 100 g of the triphenylmethane type resin obtained in Production Example B and 300 g of methanol were charged and dissolved. 11.2 g (NET) of potassium oxide was added and the mixture was stirred until it became uniform. 19.1 g of allyl chloride
Was added dropwise over 15 minutes, and the mixture was stirred at 40 ° C. for 1 hour, and further heated and stirred at 65 ° C. for 5 hours to complete the allyl etherification reaction. Next, the reaction solution was filtered to remove by-produced potassium chloride, and then methanol was removed. The residue was dissolved in methyl isobutyl ketone, washed with pure water, and then the methyl isobutyl ketone was removed to obtain an allyl etherified triphenylmethane type resin (etherification ratio: 20%). Physical properties of this etherified product were measured in the same manner as in the examples.
Table 2 shows the results.

[Example 5] (20% allyl etherified triphenylmethane resin) The equivalent ratio of the 20 mol% allyl etherified product obtained in Example 1 to the cresol novolak type epoxy resin was 1.2: 1. Except having changed, it carried out similarly to Example 1, and
Glass transition temperature and gel time were measured. Table 2 shows the results
Shown in

[Comparative Example 1] (60% allyl etherified triphenylmethane resin) Into the reaction vessel used in Example 1, 100 g of the triphenylmethane type resin obtained in Production Example A and 300 g of methanol were charged and dissolved. 33.7 g (NET) of potassium oxide was added and the mixture was stirred until uniform. 53.6 g of allyl chloride
Was added dropwise over 15 minutes, and the mixture was stirred at 40 ° C. for 1 hour, and further heated and stirred at 65 ° C. for 5 hours to complete the allyl etherification reaction. Next, the reaction solution was filtered to remove by-produced potassium chloride, and then methanol was removed. The residue was dissolved in methyl isobutyl ketone, washed with pure water, and the methyl isobutyl ketone was removed to obtain an allyl etherified triphenylmethane resin having an etherification rate of 60 mol%. Physical properties of this etherified product were measured in the same manner as in the examples. Table 2 shows the results.

Comparative Example 2 The triphenylmethane type resin obtained in Production Example A was measured for physical properties as it was without etherification. Table 2 shows the results.

[Comparative Example 3] (Production of allyl etherified phenol aralkyl resin) Into the reaction vessel used in Example 1, 100 g of the phenol aralkyl resin obtained in Production Example C and 300 g of methanol were charged and dissolved. 0.4 g was added and stirred until uniform. After 10.9 g of allyl chloride was added dropwise over 15 minutes, the mixture was stirred at 40 ° C. for 1 hour, and further heated and stirred at 65 ° C. for 5 hours to complete the allyl etherification reaction. Next, the reaction solution was filtered to remove by-produced potassium chloride, and then methanol was removed. The residue was dissolved in methyl isobutyl ketone, washed with pure water, and then the methyl isobutyl ketone was removed to obtain the desired product. Physical properties of the obtained allylated phenol aralkyl resin were measured. Table 2 shows the results.

[0051]

[Table 2]

As is evident from the results in Table 2, the triphenylmethane-type resin which is not etherified has a high glass transition point, but has a high melt viscosity and poor fluidity and adhesion. Further, an allyl etherified product having a high etherification rate has a low melt viscosity, but has a low glass transition point and cannot have good physical properties. Even if the phenol aralkyl resin is partially etherified as in the present invention, only a resin having a low glass transition point can be obtained. In comparison, the etherification rate was 5 to 50.
The triphenylmethane-type resin of the present invention etherified in the mole% range has a high glass transition point, a low melt viscosity, a short gelation time, and excellent curing properties.

[Example 6] (Production of epoxy resin composition) Epoxy resin (triphenylmethane type, Nippon Kayaku Co., Ltd.)
"EPPN-501H", epoxy equivalent 165g / e
q), the phenolic curing agent obtained in Example 1 and other compounding agents are compounded in the proportions shown in Table 3, sufficiently premixed, kneaded with a mixing roll, cooled, and pulverized. As a result, a molding material comprising the desired epoxy resin composition was obtained. With respect to the molding material thus obtained, various physical properties were measured and evaluated. Table 3 shows the results.

The physical properties of these molding materials were measured by the following methods. (1) Spiral flow Using a mold conforming to the EMMI standard, at 175 ° C, 70
It was measured at a pressure of kgf / cm ² .

(2) Melt Viscosity The minimum melt viscosity of the epoxy resin composition at 175 ° C. was measured by a flow tester method (load: 20 kgf / cm ² , nozzle: 1 mmΦ × ² mmL).

(3) Glass transition point The molding material is molded and cured (molding conditions: 175 ° C. × 150).
Second, post cure condition: 150 ° C x 2 hours + 180 ° C x
(6 hours) A cured product of 5 × 5 × 2 mm was prepared, and the glass transition point was determined by the TMA method.

[Comparative Example 4] (Production of epoxy resin composition) In Example 4, the phenolic curing agent was replaced with the phenolic curing agent obtained in Example 1 and the production example A was used.
Without etherifying the triphenylmethane type resin obtained in
A molding material comprising an epoxy resin composition was obtained in the same manner as in Example 4 except that the molding material was used as it was, and its physical properties were measured. Table 3 shows the results.

[0058]

[Table 3]

As is evident from the results in Table 3, the epoxy resin composition of the present invention using the partially etherified phenolic polymer as a curing agent has excellent low viscosity, high fluidity and high glass transition point. The partially etherified phenolic polymer of the present invention is useful as a curing agent for epoxy resins.

[0060]

According to the present invention, the triphenylmethane type phenolic resin having a high glass transition temperature and a low heat shrinkage property is obtained by partially etherifying the hydroxy group of the triphenylmethane type resin at a specific etherification rate. It was able to solve the problem of high melt viscosity, which was a drawback of triphenolmethane type resin, by making use of its features. As a result, a phenolic polymer which can be used for the latest semiconductor encapsulating materials such as BGA and can be used as an epoxy curing agent was obtained.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshihisa Sone 3, Oaza, Hikari, Kashima-shi, Ibaraki Sumikin Chemical Co., Ltd. F-term (reference) 4J033 CA01 CA05 CA11 CA12 CA13 CA42 CB18 CC03 CC08 HA12 HB01 HB08 4J036 AD01 AD07 AD08 AD09 AF01 AF06 DA01 FB08 JA07

Claims (4)

[Claims] 1. A partially etherified phenolic polymer in which 5 to 50 mol% of hydroxy groups of a triphenylmethane type resin represented by the formula (1) are etherified. Embedded image In the formula, n is 0 to 4, a, b, c, d, and e are 0 to 2, and the average number of substituted hydroxy groups per phenyl group is 0.5 to 2.0. 2. The partially etherified phenolic polymer according to claim 1, wherein the ether is an alkenyl ether. 3. The partially etherified phenolic polymer according to claim 2, wherein the ether is an allyl ether. 4. A curing agent for an epoxy resin comprising the partially etherified phenolic polymer according to claim 1.