JP2988148B2 - Novel aryl ester-added conjugated diene polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an epoxy resin composition used for a molding material, a resin for a composite material, a resin for a semiconductor sealing material, and a copper-clad laminate for a printed wiring board. The present invention relates to a novel aryl ester-added conjugated diene polymer useful as an epoxy resin curing agent for providing an epoxy resin composition having excellent properties.

[0002]

2. Description of the Related Art In recent years, demands for high-speed arithmetic processing of large computers have increased, and the density and frequency of electronic elements have been increasing. There is a need for a low dielectric constant material, which is another technique for increasing the speed. In addition, with the rapid development of mobile communication, a low-frequency signal substrate is an indispensable factor for a substrate for a weak high-frequency signal, and a low dielectric loss tangent is required. The dielectric constant and the dielectric loss tangent of glass cloth base epoxy resin laminates that are commonly used are quite large, 4.5 to 4.9 and 0.01 to 0.02, respectively, and are very large for large computers and high frequency signals. Disadvantageous. JP-A-1-163256 discloses that the composition of a phenol-added butadiene polymer and an epoxy resin has a relatively low dielectric constant and high heat resistance, but it has not been possible to reduce the dielectric constant yet. It is enough. In addition, with the high-density mounting of electronic elements, the elements have become thinner and smaller, and the thickness of the sealing material has also become extremely thin. Furthermore, as for the mounting method, since surface mounting is introduced and the electronic element package is directly exposed to the soldering temperature, there is a problem in the hygroscopicity of the package and the heat resistance when moisture is absorbed. At present, as a sealing material for electronic devices, a combination of a cresol novolak type epoxy resin and a phenol novolak curing agent is mainly used. However, due to the presence of hydroxyl groups in these resin compositions and cured products, moisture resistance is high. And it is very disadvantageous in heat resistance after moisture absorption.

[0003]

As described above, a resin cured product comprising an epoxy resin composition using a conventional curing agent has problems in dielectric properties and water resistance. The present invention has been made as a result of intensive studies in view of such circumstances, and an object thereof is to provide a thermosetting resin composition having a low dielectric constant and excellent water resistance.

[0004]

That is, the present invention relates to a compound represented by the general formula [I] X-A ₁ -O-CO-A ₂ [I] wherein X is a homopolymer of a conjugated diene having 4 to 10 carbon atoms. or copolymers by two or more conjugated dienes or other a copolymer in combination with a vinyl monomer, a ₁
Is

[0005]

Embedded image A ₂ represents a divalent aromatic group selected from

[0006]

Embedded image Represents a monovalent aromatic group selected from R ₁ and R ₂ are CH
Represents an alkyl group such as ₃ , C ₂ H ₅ , C ₃ H _7, etc., and n represents 0
~ 2. The present invention relates to an arylester-added conjugated diene-based polymer represented by the following formula: The present invention will be described in more detail.

The phenol-added conjugated diene polymer used as a raw material in the present invention can be produced as follows. First, a conjugated diene-based polymer is obtained by using a conjugated diene monomer such as butadiene, isoprene, or 1,3-pentadiene alone or in combination with two or more kinds, and further using another vinyl monomer, for example, an alkali such as lithium or sodium in a hydrocarbon solvent. It is obtained by polymerizing a metal or an organometallic compound thereof as a catalyst. Here, a conjugated diene polymer having 1,2 bonds of 50% or more is preferable. The reason for this is that the phenol addition reaction in the next step is performed smoothly, and furthermore, the 1,2 bond undergoes a cyclization reaction during the addition reaction, and the double bond disappears, so that the oxidative deterioration is suppressed, and practical properties are reduced. , The heat resistance is improved. The addition of phenols to the conjugated diene-based polymer is performed at 50 to 100 ° C. using a catalyst such as sulfuric acid, p-toluenesulfonic acid, and aluminum chloride.
It is desirable to adjust the amount of the phenol to be added so that the amount of the hydroxyl group is 0.1 to 1.0 mol per 100 g of the produced addition polymer. Specific examples of the phenols used here include phenol, o, m, p-cresol, ethylphenol, propylphenol, butylphenol, tert-butylphenol, amylphenol,
Monohydric phenols such as hexylphenol, polyhydric phenols such as hydroquinone and bisphenol A, and these may be used alone or as a mixture of two or more.

The method for producing the aryl ester-added conjugated diene polymer useful as the epoxy resin curing agent of the present invention is described below. The phenol-added conjugated diene-based polymer is obtained by dissolving in a suitable organic solvent and reacting with an aromatic carboxylic acid derivative. Here, when the reaction is exothermic and proceeds rapidly, it is desirable to carry out the reaction while cooling.
When an acid is generated, a tertiary amine such as triethylamine or pyridine may be used as a scavenger.

Specific examples of the aromatic carboxylic acid derivatives used in the present invention include benzoic acid chloride, benzoic acid bromide, methyl benzoic acid chloride, methyl benzoic acid bromide, ethyl benzoic acid chloride, ethyl benzoic acid bromide, and propyl benzoic acid chloride. Propyl benzoic acid bromide, butyl benzoic acid chloride, butyl benzoic acid bromide, etc., but are not limited thereto. The obtained crude product may be washed by dissolving it in a lipophilic organic solvent and washing the solution with water, or may be pulverized and washed with boiling water. The residual acid derivative, which is a reaction by-product, is not desirable because the electrical properties and moisture resistance of the cured resin are significantly reduced.

The epoxy resin which cures the aryl ester-added conjugated diene of the present invention as a curing agent is not particularly limited and may be any of known epoxy resins, such as bisphenol A type epoxy resin, biphenol type epoxy resin, phenol novolak Epoxy resin, cresol novolac epoxy resin, polyfunctional epoxy resin, or brominated bisphenol A epoxy resin,
Brominated phenol novolak type epoxy resin, brominated cresol novolak type epoxy resin, brominated polyfunctional epoxy resin and the like can be mentioned.

When the aryl ester-added conjugated diene of the present invention is used as a curing agent for an epoxy resin, imidazoles, tertiary amines, tertiary phosphines and the like may be added as a third component as a curing accelerator. More preferred. These curing accelerators may be used alone or 2
You may mix and use more than one kind. Here, specific examples of the imidazoles include 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2,4-dimethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, -Phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2
-Phenyl-4-methyl-5-hydroxymethylimidazole, 1-vinyl-2-methylimidazole, 1-propyl-2-methylimidazole, 2-isopropylimidazole, 1-cyanomethyl-2-methylimidazole, 1-cyanoethyl-2 In addition to -ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole and the like, masked imidazoles can be mentioned.

Specific examples of the tertiary amines include trimethylamine, triethylamine, tripropylamine, tributylamine, tetramethylbutanediamine,
Tetramethylpentanediamine, tetramethylhexadiamine, triethylenediamine, N, N-dimethylbenzylamine, N, N-dimethylaniline, N, N-dimethyltoluidine, N, N-dimethylanisidine, pyridine, picoline, quinoline, N -Methylpiperidine, N,
N'-dimethylpiperazine, 1,8-diazabicyclo-
[5,4,0] -7-undecene (DBU) and the like.

Specific examples of the tertiary phosphines include trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, triphenylphosphine, dimethylphenylphosphine, methyldiphenylphosphine and the like.

The amount of the curing accelerator used is 0.1 to 100 parts by weight of the aryl ester-added conjugated diene polymer.
03 to 5.0 parts by weight, preferably 0.5 to 1.5 parts by weight. If the amount of the curing accelerator used is less than the above range, the curing reaction is not sufficiently performed, and the strength and heat resistance are reduced. If the ratio exceeds the above range, the curing reaction is accelerated, but the electrical characteristics such as the dielectric constant are reduced.

Next, a method for producing a cured resin of an epoxy resin composition using the curing agent of the present invention will be described. First, an aryl ester-added conjugated diene polymer, an epoxy resin and a curing accelerator are mixed at a predetermined mixing ratio, heated to 150 ° C. and melted, and uniformly mixed and melted. At this time, if heating is continued for a long time, curing proceeds and molding cannot be performed. Next, the mixed resin composition was heated to 100 to 250 ° C. using a Teflon plate spacer.
A heat curing reaction is performed under a pressure of 0.5 to 10 MPa to obtain a cured resin.

[0016]

In the present invention, by using an aryl ester-added conjugated diene polymer as a curing agent for an epoxy resin, it is possible to achieve a low dielectric constant and a low water absorption of a cured resin. Although all the effects are not clear, it is considered as follows. In an epoxy resin curing agent generally used conventionally, when an epoxy resin is cured, a hydroxyl group is generated in a main chain with a ring-opening reaction of an epoxy group. Hydroxyl groups have high polarity, increase the dielectric constant of the cured resin, and also decrease the moisture resistance due to the increase in hydrophilicity. However, when an aryl ester compound is used as the curing agent, the aryl ester portion reacts during the ring-opening reaction of the epoxy group, and an ester bond is newly generated, so that a polar hydroxyl group is not generated. Therefore, it can be presumed that the epoxy resin composition of the present invention has a lower dielectric constant and a higher hygroscopicity than conventional resin compositions.

[0017]

EXAMPLES The present invention will now be described specifically with reference to specific examples, but the present invention is not limited to these examples.

Synthesis Example 1 5 L 4 equipped with a thermometer, a cooling pipe, a nitrogen introduction pipe, and a stirring rod
In a one-necked flask, 1270 g of a phenol-added butadiene polymer (manufactured by Nippon Petrochemical Co., Ltd., number average molecular weight 1000, phenolic OH equivalent 317 g / eq, trade name, Nisseki PP resin "PP-700-300"), and methyl ethyl ketone After adding 2.5 L and dissolving by stirring under a nitrogen stream, 480 g of triethylamine is added, and the inside of the reaction system is cooled down to 10 ° C. or less by an ice bath. 620 g of benzoic acid chloride was added dropwise over 2 hours. After the completion of the dropwise addition, the mixture was further reacted at room temperature with stirring for 2 hours. After completion of the reaction, triethylamine hydrochloride was removed by suction filtration, and methyl ethyl ketone was removed at 50 ° C. under reduced pressure to obtain a crude product. The obtained crude product was dissolved in 3 L of toluene, washed sufficiently with a separating funnel, and dried over anhydrous magnesium sulfate.
The toluene was removed at 50 ° C. under reduced pressure, and the residue was dried under reduced pressure at 150 ° C. for 6 hours to obtain an aryl ester-added butadiene polymer (PA-1000) as a target product. ¹³ C-NMR spectrum of the obtained aryl ester-added butadiene polymer (model: AC300P manufactured by Bruker, solvent: CDC
l ₃ , concentration: 10%) is shown in FIG. ^{In the 13} C-NMR spectrum, a peak indicating the carbonyl carbon of the ester exists at 165 ppm, and the peak of the hydroxyl-bonded carbon present in the raw material phenol-added butadiene polymer (1
52 ppm) was not present, and it was confirmed that the obtained product was the intended aryl ester-added butadiene polymer.

Synthesis Example 2 A phenol-added butadiene polymer as a raw material having a number average molecular weight of 700 (Nippon Petrochemical Co., Ltd., phenolic OH equivalent 317 g / eq, trade name, Nisseki PP resin "PP
-500-300 "), and a synthesis reaction was carried out in the same manner as in Synthesis Example 1 to obtain an aryl ester-added butadiene polymer (PA-700).

Example 1 A cresol novolak type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent: 197 g / eq, trade name) was added to 10 g of the aryl ester-added butadiene polymer (PA-1000) produced in Synthesis Example 1. Sumi Epoxy ESCN
195-6) 5 g and 0.1 g of 2-ethyl-4-methylimidazole were mixed, pulverized, melted at 160 ° C., and uniformly mixed. This resin composition was molded at a molding temperature of 200 ° C. and a molding pressure of 2 MPa using a 2 mm thick Teflon spacer.
For 2 hours to obtain a cured resin. The dielectric constant of the obtained cured resin was as low as 2.9, and the water absorption after boiling at 100 ° C. for 1 hour was as low as 0.32%.

Examples 2 to 4 Aryl ester-added butadiene polymer (PA-100)
0) 10 g of cresol novolak type epoxy resin or bisphenol A type epoxy resin (manufactured by Mitsui Chemicals, Inc., epoxy equivalent: 185 g / eq, trade name: EP)
OMIK R-140P) or brominated bisphenol A type epoxy resin (Sumitomo Chemical Co., Ltd., epoxy equivalent 395 g / eq, trade name Sumiepoxy ESB-40)
0) and 2-ethyl-4-methylimidazole were used in the same manner as in Example 1 except that the amounts used were as shown in Table 1, respectively. The obtained cured resin had a dielectric constant of 2.9 to 3.0 and a low water absorption of 0.33 to 0.38% after absorption by boiling at 100 ° C. for 1 hour. Table 1 shows their characteristics.

Examples 5-6 Using the aryl ester-added butadiene polymer (PA-700) obtained in Synthesis Example 2, a cresol novolak type epoxy resin or a bisphenol A type epoxy resin was used.
A cured resin product was produced in the same manner as in Example 1 except that the amounts of 2-ethyl-4-methylimidazole and toluene used were as shown in Table 1, respectively. Table 1 shows their characteristics.

Comparative Example 1 A novolak-type phenol resin (having a hydroxyl equivalent of 105 eq /
g, a number average molecular weight of 510), except that a cured resin product was produced in the same manner as in Example 1. The obtained cured resin had a high dielectric constant of 4.4 and a high water absorption after boiling water absorption of 0.48. Table 1 shows their characteristics.

[0024]

[Table 1]

Comparative Example 2 A novolak type phenol resin was used instead of the aryl ester-added butadiene polymer, and a bisphenol A type epoxy resin was used as the epoxy resin.
A resin cured product was produced in the same manner as in Example 1. The obtained cured resin had a high dielectric constant of 4.3, and the water absorption after boiling water absorption was as high as 0.51. Table 1 shows their characteristics.

Test Method The dielectric constant of the cured resin was measured using a Yokogawa-Hewlett-Packard HP16451B dielectric measurement device according to JIS-C.
Measured according to -6481. Water absorption of cured resin is 5
Using a 0 × 50 × 2 mm resin plate, the water was boiled and absorbed for 1 hour at 100 ° C., and then the weight increase was calculated.

[0027]

As described above, the aryl ester-added conjugated diene-based polymer of the present invention provides a cured epoxy resin having a low dielectric constant and excellent moisture resistance. Is great.

[Brief description of the drawings]

FIG. 1 shows a ¹³ C-NMR spectrum of an aryl ester-added butadiene polymer of the present invention (model: AC3 manufactured by Bruker)
00P, solvent: CDCl ₃ , concentration: 10%).

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takeshi Horiuchi 1500 Oji Ogawa, Shimodate City, Ibaraki Pref.Hitachi Chemical Industry Co., Ltd. (56) References JP-A-63-268703 (JP, A) JP-A-4-266920 (JP, A) JP-A-61-126162 (JP, A) JP-A-6-107909 ( JP, A) JP 3-41106 (JP, B2) WO 91/9062 (WO, A1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 8/00-8/50 C08C 19/00-19/44 C08G 59/40-59/66

Claims (4)

(57) [Claims] (1) General formula [I] X-A ₁ -O-CO-A ₂ [I] (wherein X is a homopolymer of a conjugated diene having 4 to 10 carbon atoms or a conjugate of two or more types thereof) copolymers according dienes, or other a copolymer in combination with a vinyl monomer, a ₁
Is And A ₂ represents a divalent aromatic group selected from Represents a monovalent aromatic group selected from R ₁ and R ₂ are CH
Represents an alkyl group such as ₃ , C ₂ H ₅ , C ₃ H _7, etc., and n represents 0
~ 2. ) An arylester-added conjugated diene polymer represented by the formula: 2. The aryl ester-added conjugated diene polymer according to claim 1, wherein X is polybutadiene. 3. The arylester-added conjugated diene polymer according to claim 1, wherein A ₁ is a phenylene group and A ₂ is a phenyl group. 4. A ₁ is embedded image And the aryl ester-added conjugated diene polymer according to claim 1 or 2, wherein A ₂ is a phenyl group.