JPH05331284A - Soluble polyimide resin - Google Patents

Abstract

PURPOSE:To obtain a soluble polyimide resin having excellent heat-resistance, moldability and low hygroscopicity and useful as electric and electronic materials, etc., by reacting a specific tetracarboxylic acid dianhydride with a specific amine component at a specific ratio and subjecting the product to imide-cyclization process. CONSTITUTION:The resin is produced by reacting (A) an acid component consisting of (a) mol of 4,4'-hydroxyphthalic acid dianhydride and (b) mol of one or two kinds of tetracarboxylic acid dianhydrides selected from 3,3',4,4'- biphenyltetracarboxylic acid dianhydride and 3,3',4,4'- benzophenonetetracarboxylic acid dianhydride with (B) an amine component consisting of (c) mol of one or more kinds of diamines of formula (X is H or F; n is 0 or 1), (d) mol of 1,3-bis(3-aminophenoxy)benzene and (e) mol of alpha,omega-bis(3-aminopropyl)polydimethylsiloxane at a molar ratios of a/(a+b)<=0.6, 0.05<=e/(c+d+e)<=0.5 and 0.1<=d/(c+d+e)<=0.9 and subjecting the product to imide-cyclization process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide resin which has excellent heat resistance, low hygroscopicity, is soluble in an organic solvent having a low boiling point, and has excellent moldability.

[0002]

2. Description of the Related Art Polyimide resins are widely used as electric and electronic materials because of their high heat resistance, flame resistance and excellent electric insulation. As a film, it is widely used as a base material for flexible printed wiring boards and heat-resistant adhesive tapes, and as a resin varnish for semiconductor insulating films and protective films.
However, conventional polyimide resins have high hygroscopicity and excellent heat resistance, but on the other hand, they are insoluble and infusible or have extremely high melting points, so that they cannot be said to be easy-to-use materials in terms of workability. It is used as a mounting material for semiconductors in interlayer insulating films and surface protective films.These are coated with a precursor polyamic acid soluble in an organic solvent on the semiconductor surface, and the solvent is removed by heat treatment and imidization is performed. proceeding. The acid amide-based solvent used at this time has a high boiling point, which may cause foaming of the coating film or 250 ° C to completely evaporate the solvent.
Since the above high temperature drying process is required and the device is exposed to high temperature, the yield of the assembly process is deteriorated. Further, since the film has a high hygroscopic property, there is a problem that the moisture absorbed at a high temperature evaporates at once and causes swelling and cracks.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The present invention has been earnestly studied to obtain a polyimide resin having excellent heat resistance, low hygroscopicity, and solubility in an organic solvent and excellent moldability.
The inventors have found that a polyimide resin having a specific structure solves the above problems, and arrived at the present invention.

[0004]

DISCLOSURE OF THE INVENTION The present invention comprises a mol of 4,4'-oxydiphthalic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 3,3', One type represented by the general formula (1) using one or two types of tetracarboxylic dianhydride b moles selected from the group consisting of 4,4′-benzophenone tetracarboxylic dianhydride as an acid component. Alternatively, c moles of two or more kinds of diamines, d moles of 1,3-bis (3-aminophenoxy) benzene and α, ω-bis (3-aminopropyl)
With polydimethylsiloxane emol as an amine component,
The molar ratio of a, b, c, d, e is a / (a + b) ≧ 0.
6, 0.05 ≤ e / (c + d + e) ≤ 0.5, and 0.1 ≤ d
It is a polyimide resin soluble in an organic solvent in which both components are reacted at a ratio of /(c+d+e)≦0.9 to cause imide ring closure.

Used to obtain the polyimide resin of the present invention
4,4'-oxydiphthalic dianhydride is represented by the formula (2), 3,3 ', 4,4'
-Biphenyltetracarboxylic dianhydride is represented by the formula (3), 3,
3 ', 4,4'-benzophenone tetracarboxylic dianhydride is represented by formula (4), 1,3-bis (3-aminophenoxy) benzene is represented by formula (5), α, ω-bis (3-aminopropyl) The polydimethylsiloxane is represented by the formula (6).

[0006]

[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical 4]

[Chemical 5]

[Chemical 6]

The molar ratio of 4,4'-oxydiphthalic dianhydride, which is the main constituent of the acid component, is extremely important for the solubility of the polyimide resin obtained. The feature of the invention of dissolution is lost.

The diamine represented by the general formula (1) is 2,2-
Bis (4- (4-aminophenoxy) phenyl) propane (BA
PP), 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane (BAPPF), 2,2-bis (4-aminophenoxy) hexafluoropropane (BAP
F), bis-4- (4-aminophenoxy) phenyl sulfone (BAPS), bis-4- (3-aminophenoxy) phenyl sulfone (BAPSM) and the like.

The α, ω-bis (3-aminopropyl) polydimethylsiloxane represented by the formula (6) preferably has n = 0 to 10, and particularly when the value of n is 4 to 10, the glass transition temperature is It is preferable in terms of adhesiveness and heat resistance. In addition, blending n = 0 and the above n = 4 to 10 is preferable especially for applications where importance is attached to adhesiveness.

It is important that the amount ratio of each component is within the above range. If the content of α, ω-bis (3-aminopropyl) polydimethylsiloxane is less than 5 mol% of the total amine components, low hygroscopicity is characteristic. When it does not appear and exceeds 50 mol%, the glass transition temperature is remarkably lowered and a problem occurs in heat resistance. The same applies to the molar ratio of 1,3-bis (3-aminophenoxy) benzene, and if it exceeds the above range, problems occur in solubility and heat resistance.

The equivalent ratio of the acid component and the amine component in the polycondensation reaction is an important factor that determines the molecular weight of the polyamic acid obtained. It is well known that there is a correlation between the molecular weight of polymers and physical properties, particularly the number average molecular weight and mechanical properties. The larger the number average molecular weight, the better the mechanical properties. Therefore, in order to obtain practically excellent strength, it is necessary that the polymer has a high molecular weight to some extent. In the present invention,
The equivalent ratio r of the acid component and the amine component is more preferably 0.900 ≤ r ≤ 1.06, and more preferably 0.975 ≤ r ≤ 1.06. However, r = [equivalent number of all acid components] / [equivalent number of all amine components]. r is 0.
If it is less than 900, the molecular weight is low and it becomes brittle, so the adhesive strength becomes weak. On the other hand, when it exceeds 1.06, unreacted carboxylic acid may be decarboxylated during heating, causing gas generation and foaming, which is not preferable.

The reaction between the tetracarboxylic dianhydride and the diamine is carried out by a known method in an aprotic polar solvent. The aprotic polar solvent is N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA
C), N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), diglyme, cyclohexanone,
1,4-dioxane and the like. The aprotic polar solvent is
Only one type may be used, or two or more types may be mixed and used. At this time, a non-polar solvent compatible with the aprotic polar solvent may be mixed and used. Aromatic hydrocarbons such as toluene, xylene and solvent naphtha are often used. The proportion of the nonpolar solvent in the mixed solvent is preferably 30% by weight or less. This is because if the amount of the non-polar solvent is 30% by weight or more, the dissolving power of the solvent may decrease and polyamic acid may precipitate. The reaction of the tetracarboxylic acid dianhydride and the diamine is carried out by dissolving a well-dried diamine component in the dehydrated and purified reaction solvent described above, and the ring closure rate is 98%, more preferably 99% or more of the well-dried tetracarboxylic acid dianhydride. Anhydride is added to drive the reaction.

The polyamic acid solution thus obtained is subsequently heated and dehydrated in an organic solvent to form an imidized polyimide. Since the water generated by the imidization reaction interferes with the ring-closing reaction, an organic solvent that is incompatible with water is added to the system to azeotropically evaporate it and use a device such as a Dean-Stark tube to remove it from the system. To discharge. Dichlorobenzene is known as an organic solvent that is incompatible with water, but for electronics use, the aromatic hydrocarbon is preferably used because chlorine components may be mixed therein. Further, the use of compounds such as acetic anhydride, β-picoline and pyridine as a catalyst for the imidization reaction is not hindered.

In the present invention, the higher the degree of imide ring closure, the better. If the imidization ratio is low, imidization occurs due to heat during use and water is not generated, which is not preferable. Therefore, 95% or more, more preferably 98% or more. It is desirable that the imidization ratio of is achieved.

In the present invention, the obtained polyimide solution can be used as it is as a coating varnish. Also,
The polyimide solution may be poured into a poor solvent to reprecipitate and precipitate the polyimide resin to remove unreacted monomers, purified, and dried to be used as a solid polyimide resin. In applications where high-temperature processes are disliked or where impurities and foreign substances are particularly problematic, it is preferable to dissolve them again in an organic solvent to obtain a filtration / purification varnish. As the solvent used at this time, a solvent having a low boiling point can be selected in consideration of workability.

In the polyimide resin of the present invention, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone are used as ketone solvents, and 1,4-dioxane, tetrahydrofuran, and diglyme are used as ether solvents having a boiling point of 200 ° C. or less. It can be used as a low boiling point solvent. These solvents may be used alone or in combination of two or more.

The method of using the polyimide resin of the present invention is not particularly limited, but it can be dissolved in an organic solvent to form a resin varnish for coating or dipping, cast for forming a film, or solid for extrusion. It can be used as an insulating material, an adhesive film or the like having both heat resistance and processability.

[0018]

The polyimide resin of the present invention is a polyimide resin having a specific structure that is soluble in an organic solvent even after being completely imidized, and although it has excellent heat resistance, it is thermosetting with a chemical reaction. Molding is possible in a shorter time than resin. Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[0019]

【Example】

(Example 1) NMP750 dehydrated and refined in a four-necked flask equipped with a dry nitrogen gas introduction tube, a condenser, a thermometer, and a stirrer.
Add g and stir vigorously for 10 minutes while flowing nitrogen gas. Next, 1,3-bis (3-aminophenoxy) benzene (AP
B) 73.0847 g (0.250 mol) and α, ω-bis (3-aminopropyl) polydimethylsiloxane (APPS) 37.8163 g
(Average molecular weight 840.36, 0.045 mol), α, ω-bis (3-aminopropyl) tetramethyldimethylsiloxane (APP
S, n = 0) 1.4971 g (0.006 mol, n in formula (6)
= 0), heat the system to 60 ° C and stir until uniform. After uniform dissolution, cool the system to 5 ° C in an ice-water bath,
4'-Oxydiphthalic acid dianhydride (ODPA) 93.4404g
(0.301 mol) was added as a powder over 15 minutes, and then stirring was continued for 3 hours. During this time, the flask was kept at 5 ° C.

Thereafter, the nitrogen gas introducing pipe and the cooler were removed,
A Dean-Stark tube filled with xylene was attached to the flask, and 187 g of toluene was added to the system. The system was replaced with an oil bath and the system was heated to 175 ° C. to remove water generated outside the system. After heating for 4 hours, generation of water from the system was not observed. After cooling, this reaction solution was poured into a large amount of methanol to precipitate a polyimide resin. After filtering solids at 80 ° C
186.28 g (yield 90.5%) after removing the solvent by drying under reduced pressure for 12 hours
Of solid resin was obtained. The infrared absorption spectrum was measured by the KBr tablet method to find that it was 5.6 μm derived from the cyclic imide bond.
Although the absorption of 6.06 μm derived from the amide bond was not observed, it was confirmed that this resin was almost 100% imidized.

It was confirmed that the polyimide resin thus obtained was well soluble in cyclohexanone / toluene (90/10 w / w%). At this time, the molar ratios of acid and amine are a / (a + b) = 1 and d / (c + d + e), respectively.
= 0.83 and e / (c + d + e) = 0.17.

(Examples 2 to 5) In the same manner as in Example 1,
Soluble polyimide resin was obtained by reacting with the formulation shown in Table 1. The evaluation results obtained for these polyimide resins are shown in Table 1. It can be seen that all have excellent solubility in organic solvents.

[0023]

[Table 1]

In Table 1, ODPA is 4,4'-oxydiphthalic dianhydride, BTDA is 4,4'-benzophenonetetracarboxylic dianhydride, and BPDA is 3,3 ', 4,4'. -Biphenyltetracarboxylic dianhydride, APB is 1,3-bis (3-aminophenoxy) benzene, and BAPPF is 2,2-
Bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, APPS is α, ω-bis (3-aminopropyl)
Each is an abbreviation for polydimethylsiloxane.

In addition, the numerical value of the compound is the compound equivalent ratio in each component, and the water absorption rate is 500 at 85 ° C. and 85% RH.
Saturated water absorption after leaving for a while (HH-500 treatment)
The generated water is a value obtained by quantifying the gas generated by heating at 250 ° C. for 15 minutes by the GC-MS method, and the water content by the Karl Fischer method. S in the solubility column indicates that the compound is soluble in the corresponding solvent.

(Comparative Example 1) Under the same conditions as in Example 1, 4,4'-
Oxydiphthalic acid dianhydride, 1,3-bis (3-aminophenoxy) benzene, and 2,2-bis (4- (4-aminophenoxy) phenyl) propane were added to a / (a + b) = 1, c / (c + d +).
e) = 0.3 and d / (c + d + e) = 0.7 were reacted to obtain a polyimide resin. An attempt was made to dissolve this resin in cyclohexanone, but it was in a swollen gel state and could not be completely dissolved. Moreover, the same state was obtained for DMF and DMAC, and the resin varnish could not be prepared.

(Comparative Examples 2 to 5) As in Example 1, the second
Table 2 shows the results of evaluation of the polyimide resin obtained by reacting with the formulation shown in the table.

[0028]

[Table 2]

In Table 2, PMDA is 1,2,4,5-
Benzenetetracarboxylic dianhydride, 4,4'-DDE
Abbreviation of 4,4′-diaminodiphenyl ether, I in the solubility column indicates insolubility in the corresponding solvent.
The above examples show that the present invention can provide a polyimide resin that is soluble in an organic solvent and has excellent heat resistance and low hygroscopicity.

[0030]

According to the present invention, it is possible to provide a polyimide resin having excellent heat resistance and moldability. Since it is soluble in a low boiling point solvent, it is possible to almost completely eliminate the residual solvent, and since it has already been imidized, a high temperature process is unnecessary and no water is generated. Therefore, it is industrially extremely useful as a material for electronics that requires high reliability and heat resistance.

Claims (1)

[Claims] 1. A mol of 4,4′-oxydiphthalic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride
In the general formula (1), one or two kinds of tetracarboxylic acid dianhydride b mole selected from the group consisting of 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dianhydride is used as an acid component. 1 type or 2 or more types of diamine c mole represented,
D-mol of 1,3-bis (3-aminophenoxy) benzene and α,
ω-bis (3-aminopropyl) polydimethylsiloxane e
Moles are amine components, and the molar ratio of a, b, c, d, e is a / (a + b) ≧ 0.6, 0.05 ≦ e / (c + d + e)
A polyimide resin soluble in an organic solvent, which is obtained by reacting both components at a ratio of ≦ 0.5 and 0.1 ≦ d / (c + d + e) ≦ 0.9 to imide-cycle closure. [Chemical 1]