JP3233892B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to heat resistance, adhesiveness,
The present invention relates to a heat-resistant resin composition having excellent low outgassing properties and low-temperature processability.

[0002]

2. Description of the Related Art Polyimide resin has high heat resistance, flame retardancy and excellent electrical insulation, so it is used as a film for a substrate of a flexible printed wiring board or a heat-resistant adhesive tape, and as a resin varnish, an interlayer insulating film of a semiconductor. Widely used for surface protection film. In recent years, adhesives excellent in low-temperature processability and heat resistance have been demanded, and hybrid adhesives of thermoplastic polyimide resin and epoxy resin (for example, see
247426 and JP-A-7-247408) have been devised.

[0003]

However, these adhesives have a problem in that the epoxy resin component is generated as a gas and contaminates the apparatus and the adherend. As a method of preventing gasification of the epoxy resin component, there is a method of increasing the molecular weight of the epoxy resin component. When a commercially available high molecular weight epoxy resin was used, no gas was generated, but at the same time, the adhesive strength was reduced, and the performance as an adhesive was low.
The present invention has been intensively studied to obtain a resin having excellent heat resistance, adhesiveness, low outgassing property, and low temperature processability. As a result, a polyimide resin having a specific structure is reacted with oligoethylene glycol diglycidyl ether and bisphenol A. The inventors have found that the above-mentioned problems can be solved by adding a polymer having excellent flexibility obtained by the above-described process, and have reached the present invention.

[0004]

Means for Solving the Problems The heat-resistant resin composition of the present invention comprises a polyimide resin 100 having a structure of the structural formula [I].
Parts by weight, obtained by reacting oligoethylene glycol diglycidyl ether with bisphenol A
1 to 1 of the bifunctional chain-extended epoxy resin represented by the structural formula [II]
A heat-resistant resin composition comprising, as main components, 00 parts by weight and 0.26 to 5.10 parts by weight of aminosilane.

Embedded image However, m の an integer of 3 or more n 整数 an integer of 2 or more and less than 8

[0005]

Embedded image Provided that R ₁ , R ₂ １ a monovalent aliphatic or aromatic hydrocarbon group having 6 or less carbon atoms n ‥‥‥ an integer of 6 or more and less than 16

[0006] The polyimide resin of the present invention needs to have a polysiloxane structure represented by the structural formula [I] in its main chain. The chain length n of this polysiloxane is 6 to
15 is preferable, and the value of n is particularly preferably in the range of 6 to 10 from the viewpoints of glass transition temperature, adhesiveness, and heat resistance. n is 5
In the following cases, a high temperature or a long time is required for the bonding step. Conversely, when n is 16 or more, the heat resistance of the polyimide decreases.

The polysiloxane structure can be introduced by using a silicone diamine such as α, ω-bis (3-aminopropyl) polydimethylsiloxane as a raw material when producing a polyimide.

In the production of polyimide, other aromatic diamines such as 2,2'-bis (4- (4-aminophenoxy) phenyl) propane, 1,3-bis (3-aminophenoxy) benzene, 2,2'-bis
(4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2'-bis (4-aminophenoxy)
One or more of hexafluoropropane, bis-4- (4-aminophenoxy) phenylsulfone, bis-4- (3-aminophenoxy) phenylsulfone, and the like, and the silicone diamine are used in combination.

[0009] The polyimide resin of the present invention comprises 3,3 ',
4,4′-biphenyltetracarboxylic dianhydride, 3,
One or more tetracarboxylic acids obtained from the group consisting of 3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride and ethylene glycol bistrimellitic dianhydride Desirably, it is obtained by polymerizing carboxylic dianhydride and aromatic diamine.

[0010] The reaction between the tetracarboxylic dianhydride and the diamine is carried out by a known method in an aprotic polar solvent. The aprotic polar solvents include N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAC), N-methyl-2-pyrrolidone (NM
P), tetrahydrofuran (THF), diglyme, cyclohexanone, 1,4-dioxane (1,4-DO)
Etc. can be used. As the aprotic polar solvent, only one kind may be used, or two or more kinds may be used as a mixture. At this time, a non-polar solvent compatible with the aprotic polar solvent may be mixed and used. For example, aromatic hydrocarbons such as toluene, xylene, and solvent naphtha are used. The proportion of the non-polar solvent in the mixed solvent is
It is preferably at most 30% by weight. This is because if the nonpolar solvent is 30% by weight or more, the solvent power of the solvent may be reduced and polyamic acid may be precipitated. The reaction between the tetracarboxylic dianhydride and the diamine is carried out by dissolving the well-dried diamine component in the above-mentioned reaction solvent that has been dehydrated and purified, and adding thereto the ring-closing rate of 98%, more preferably 99% or more. The reaction is allowed to proceed by adding the anhydride.

The polyamic acid solution thus obtained is subsequently heated and dehydrated and cyclized in an organic solvent to give an imidized polyimide. Since the water generated by the imidization reaction interferes with the ring closure reaction, an organic solvent incompatible with water is added to the system and azeotroped to form Dean-Stark (Dean-Stark).
k) Discharge out of the system using a device such as a pipe. Dichlorobenzene is known as an organic solvent that is not compatible with water, but the above-mentioned aromatic hydrocarbon is preferably used for electronics because a chlorine component may be mixed therein. Acetic anhydride, β-
It does not prevent the use of compounds such as picoline and pyridine. The higher the imidization ratio, the better. If the imidization ratio is low, imidization occurs due to heat during use such as thermocompression and water is generated, which is not preferable.
It is desirable that the above imidation ratio is achieved. The polyimide resin used preferably has a structure of the structural formula [I] in the main chain. This is because they are excellent in low water absorption and can be bonded in a short time at a low temperature.

As a phenol compound used as a raw material of the chain-extended epoxy resin , bisphenol A is most preferably used in order to obtain a chain-extended epoxy resin having high heat resistance and excellent flexibility. As epoxy resin used as a raw material for chain extension epoxy resin, in order to obtain an excellent chain extender epoxy resin flexible properties, the best to use oligoethylene glycol diglycidyl ether. Further, when the number of repetitions n of the oligoethylene glycol diglycidyl ether is 1 (Structural formula [II]), the flexibility of the chain-extended epoxy resin is relatively low, and the high molecular weight of a commercially available bisphenol A type epoxy resin. It has similar properties. On the other hand, when n is 8, the flexibility of the chain-extended epoxy resin becomes too high, and a flow occurs during pressure bonding. Therefore, n is 2 or more and 8
Less is better. The chain-extended epoxy resin has a molecular weight of 2,
000 or more are preferred. If the molecular weight is less than 2,000, the epoxy resin volatilizes or decomposes due to heating during thermocompression bonding to generate gas.

[0013]

Embedded image However, m の an integer of 3 or more n 整数 an integer of 2 or more and less than 8

The amount ratio of the chain-extended epoxy resin is preferably 1 to 100 parts by weight, particularly preferably 20 to 50 parts by weight, based on 100 parts by weight of the polyimide resin. If the amount is less than 1 part by weight, the effect of improving the peel strength is unlikely to be exhibited.
If the amount exceeds 00 parts by weight, the heat resistance of the resin is impaired, which is not preferable. The compounding ratio of aminosilane is 0.26 to 5.10 parts by weight with respect to 100 parts by weight of the polyimide resin, which means that the active hydrogen of the amine is equivalent to the epoxy group and the chemical equivalent.

A resin composition solution can be obtained by adding a chain-extended epoxy resin or aminosilane as it is to the obtained polyimide solution. Further, the polyimide solution may be poured into a poor solvent before addition of an epoxy resin or the like, and the polyimide resin may be reprecipitated to remove unreacted monomers, purified, dried, and used as a solid polyimide resin. . In applications that dislike the high-temperature process, or particularly in applications where impurities or foreign matter becomes a problem, it is preferable to dissolve again in an organic solvent to obtain a filtration and purification varnish. The solvent used at this time can be selected from solvents having a low boiling point in consideration of workability.
In the polyimide resin of the present invention, as a ketone-based solvent, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, as an ether-based solvent, 1,4-dioxane, tetrahydrofuran, diglyme is a low-boiling solvent having a boiling point of 200 ° C or less. Can be used as These solvents may be used alone or in combination of two or more.

In the resin composition of the present invention obtained by adding a chain-extended epoxy resin and an aminosilane to the polyimide resin, since the polyimide resin and the epoxy resin undergo phase separation, the apparent glass transition temperature is the same as the glass transition temperature of the polyimide resin. It is about the same and maintains high heat resistance. On the other hand, the low-temperature processability is improved over the polyimide resin due to the addition of a chain-extended epoxy resin having excellent flexibility, and the physical properties such as no peeling are observed even when a thermal shock such as IR reflow is applied. Further, the amount of gas generated at the time of heating at 300 ° C. is extremely small. As described above, a resin composition having excellent heat resistance, adhesion, and low outgassing properties can be obtained. Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[0017]

EXAMPLES (Synthesis of polyimide resin) A four-necked flask equipped with a dry nitrogen gas inlet tube, a cooler, a thermometer, and a stirrer was prepared.
Add 791 g of dehydrated and purified NMP, and vigorously stir for 10 minutes while flowing nitrogen gas. Next, 2,2-bis (4
-(4-aminophenoxy) phenyl) propane (BA
PP) 73.8926 g (0.180 mol), 1,3-bis
(3-Aminophenoxy) benzene (APB) 17.540
2 g (0.060 mol), α, ω-bis (3-aminopropyl) polydimethylsiloxane (APPS) 50.2
Charge 200 g (average molecular weight 837, 0.060 mol), heat the system to 60 ° C. and stir until uniform.
After dissolving uniformly, the system was cooled to 5 ° C in an ice-water bath,
4,4'-biphenyltetracarboxylic dianhydride (BP
DA) 44.1330 g (0.150 mol), ethylene glycol bistrimellitic dianhydride (TMEG) 6
1.5445 g (0.150 mol) in powder form
The addition was made over 5 minutes and then stirring was continued for 3 hours. During this time, the flask was kept at 5 ° C.

After that, remove the nitrogen gas inlet pipe and the cooler,
A Dean-Stark tube filled with xylene was attached to the flask, and 198 g of xylene was added to the system. The system was heated to 175 ° C. instead of the oil bath, and the generated water was removed from the system. 4
After heating for an hour, no water was generated from the system. After cooling, the reaction solution was poured into a large amount of methanol to precipitate a polyimide resin. After filtering the solids,
The solvent was removed by vacuum drying at 80 ° C. for 12 hours to remove the solvent.
g (yield 92.1%) of a solid resin was obtained. When an infrared absorption spectrum was measured by a KBr tablet method, an absorption of 5.6 μm derived from the cyclic imide bond was recognized, but an absorption of 6.06 μm derived from the amide bond could not be recognized.
It was confirmed that this resin was almost 100% imidized. The polyimide resin thus obtained has a glass transition temperature of 148 ° C. and a tensile modulus of 180 kgf / m.
m ² , it was confirmed to be well dissolved in dimethylformamide (DMF) and 1,4-dioxane (1,4-DO).

(Synthesis of Chain-Extended Epoxy Resin) (Example 1) Diethylene glycol diglycidyl ether (Denacol EX8) was placed in a flask equipped with a thermometer and a stirrer.
50, manufactured by Nagase Kasei Kogyo Co., Ltd.) and 100.15 g of bisphenol A (manufactured by Wako Pure Chemical Industries, Ltd.), and stirred at 80 ° C. until uniform. Thereafter, 1.00 g of triphenylphosphine (manufactured by Wako Pure Chemical Industries, Ltd.) is added to the mixed solution, and the mixture is stirred at 80 ° C. until uniform. Thereafter, stirring was continued at 80 ° C. for 2 hours, transferred to an aluminum container, and then reacted at 150 ° C. for 2 hours. And the weight loss rate of these chain extended epoxy resins at 300 ° C. was measured. Table 1 shows the results.
The thermogravimetric loss of the chain-extended epoxy resin was measured using TG-
Using DTA, from room temperature to 800 at a heating rate of 5 ° C / min.
° C.

[0020]

[Table 1]

(Comparative Examples 1, 2, 3, 4) A chain-extended epoxy resin was synthesized in the same manner as in Example 1 with the composition shown in Table 1, and the weight loss rate at 300 ° C. was measured. Table 1 shows the obtained results.

Example 2 NMP solution of polyimide synthesized in a glass flask (resin content 35%) 100.00
Insert g. Then, 1.75 g of a chain-extended epoxy resin having a molecular weight of 2000 or more synthesized in Example 1 and 0.09 of aminosilane (KBM573, Shin-Etsu Chemical Co., Ltd.)
g and stir until uniform. The resin solution thus obtained was applied to one side of a copper foil (18 μm) with a coating machine to obtain a tape having an adhesive layer thickness of 20 μm. Drying conditions were 80 ° C for 10 minutes, 120 ° C for 10 minutes, and then 180 ° C.
C. for 10 minutes. Apply this adhesive tape to the IC chip.
A test piece was prepared by thermocompression bonding at 60 ° C. for 10 seconds, and a 90 ° peel test was performed with a tensile tester. The result is shown in FIG. The pressure applied to the bonding surface during thermocompression bonding was 12 kgf / cm from the result calculated from the gauge pressure and the bonding area.
^{Was 2} . The crosshead speed during the tensile test was 20 mm / min.

(Examples 3, 4, 5, 6, 7 and Comparative Example 5)
A resin solution was prepared in the same manner as in Example 2 with the composition shown in Table 2 to obtain an adhesive tape. The results of the obtained peel strength are shown in FIG.

[0024]

[Table 2]

From the results shown in Table 1, as the amount of the epoxy compound having a molecular weight of less than 2,000 contained in the chain-extended epoxy resin decreases, the weight loss rate at the time of heating at 300 ° C. decreases. The chain-extended epoxy resin containing no epoxy compound having a molecular weight of less than 2000 showed almost no weight loss at 300 ° C.

From the results of FIG. 1, it is shown by the structural formula [II] obtained by reacting oligoethylene glycol diglycidyl ether and bisphenol A with a polyimide resin having the structure of the structural formula [I] in the main chain. Molecular weight 2,
As more than 000 chain-extended epoxy resins are added,
The peel strength of the polyimide resin was increased. The peel strength showed a maximum value in a system in which the amount of the chain-extended epoxy resin was 30 parts by weight, and the value was 1.8 times that in the system without the addition. From the above Examples and Comparative Examples, the structural formula
Heat resistance is obtained by mixing aminosilane with a chain-extended epoxy resin represented by the structural formula [II] obtained by reacting oligoethylene glycol diglycidyl ether and bisphenol A with a polyimide resin having the structure of [I]. This shows that a resin having excellent properties, adhesiveness, low outgassing properties and low-temperature processability can be obtained.

[0027]

According to the present invention, it is possible to provide a highly reliable adhesive excellent in heat resistance, adhesiveness, low outgassing and low-temperature processability. A chain-extended epoxy resin represented by the structural formula [II] obtained by reacting oligoethylene glycol diglycidyl ether and bisphenol A with a polyimide resin having a structure of the structural formula [I] in the main chain, and an aminosilane By mixing, the low temperature processability and the peel strength can be increased while maintaining the heat resistance of the polyimide. Then, the amount of gas generated at the time of heating at 300 ° C. is extremely small, so that the worker can work safely. For this reason, it is extremely useful industrially as a material for electronics requiring high reliability and heat resistance.

[Brief description of the drawings]

FIG. 1 is a diagram showing the effect of the amount of chain-extended epoxy resin added on the peel strength.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 79/00-79/08 C08L 63/00-63/10 C08K 3/00-13/08

Claims (1)

(57) [Claims] 1. 100 parts by weight of a polyimide resin having the structure of the structural formula [I], 1 to 100 parts by weight of a chain-extended epoxy resin having a molecular weight of 2,000 or more, 0.26 of aminosilane
Containing ～5.10 parts as essential components, a chain extender Epo
The oxy resin is oligoethylene glycol diglycidyl ether
By reacting tertel with bisphenol A
The resulting structure formula [II] to the resin composition, wherein the epoxy resin der Rukoto shown. Embedded image However, R _1, R ₂ ‥‥‥ ₁ monovalent aliphatic having 6 or less carbon or aromatic hydrocarbon radical n ‥‥‥ of less than 6 to 16 integer embedded image However, m の an integer of 3 or more n 整数 an integer of 2 or more and less than 8