JP3093063B2 - Soluble polyimide resin - Google Patents

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 is excellent in heat resistance, low in hygroscopicity, soluble in an organic solvent having a low boiling point and excellent in 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 retardancy and excellent electrical insulation. It is widely used as a film for substrates of flexible printed wiring boards and heat-resistant adhesive tapes, and as a resin varnish for insulating and protective films of semiconductors. However, conventional polyimide resins have high hygroscopicity and excellent heat resistance, but are insoluble, infusible, or extremely high in melting point, and cannot be said to be easy-to-use materials in terms of workability. It is also used as a semiconductor mounting material for interlayer insulating films, surface protective films, etc. These are applied to the semiconductor surface with a precursor polyamic acid that is soluble in an organic solvent, and the solvent is removed and imidized by heat treatment. We are promoting. The acid amide-based solvent used at this time has a high boiling point, which may cause foaming of the film, requires a high-temperature drying step of 250 ° C or more to completely evaporate the solvent, and exposes the element to a high temperature. Deteriorates yield. Also,
Due to the high hygroscopicity of the film, there has been a problem that moisture absorbed at high temperature evaporates at a stretch, causing swelling and cracking.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of intensive studies to obtain a polyimide resin having excellent heat resistance, low hygroscopicity, and excellent moldability which is soluble in an organic solvent.
The inventors have found that a polyimide resin having a specific structure solves the above-mentioned problems, and have reached the present invention.

[0004]

According to the present invention, there are provided 2,4-bis (4- (4- (4- (4- (4- (4- Aminophenoxy)
Phenyl) propane c mole, one or two kinds of diamines selected from the group of 1,3-bis (3-aminophenoxy) benzene and dimethylphenylenediamine, and d, α,
ω-bis (3-aminopropyl) polydimethylsiloxane e
3 or 4 components consisting of an amine component,
The molar ratio of b, c, d and e is a / (a + b) ≧ 0.8, b
/(A+b)≦0.2 and 0.05 ≦ e / (c + d + e)
A polyimide resin that is soluble in an organic solvent in which both components are reacted at a ratio of ≦ 0.5 to form an imide ring-closure, and the molecular terminal of the polyimide resin is fmol of an acid anhydride represented by the general formula (1) or Aromatic amine g represented by the formula (2)
End-cap with mol, a, b, c, d, e, f, g
The molar ratio of a / (a + b + 0.5f) ≧ 0.8, b / (a +
b + 0.5f) ≦ 0.2,0.01 ≦ f / (a + b + 0.5f) ≦
0.05,0.01 ≦ g / (c + d + e + 0.5g) ≦ 0.05,0.
05 ≦ e / (c + d + e + 0.5g) ≦ 0.5, and either f or g is a polyimide resin soluble in an organic solvent in which imide is closed by reacting both components at a ratio of 0.

Embedded image (Where X is

Embedded image At least one group selected from

Embedded image (Wherein, Y is a hydrogen atom or at least one group selected from methyl, ethyl, propyl, butyl, phenyl, methoxy, ethoxy, propoxy, butoxy, or phenoxy groups)

The α, ω-bis (3-aminopropyl) polydimethylsiloxane used to obtain the polyimide resin of the present invention is represented by the formula (3).

Embedded image

[0006] The ratio of 4,4'-oxydiphthalic dianhydride, which is a main component of the acid component, is extremely important for the solubility of the polyimide resin to be obtained. The feature of the invention of dissolving is lost.

In the α, ω-bis (3-aminopropyl) polydimethylsiloxane represented by the formula (3), n = 0 to 10 is preferable. Particularly, when the value of n is in the range of 4 to 10, the glass transition temperature, It is preferable from the viewpoint of adhesiveness and heat resistance. It is preferable to use a blend of n = 0 and the above n = 4 to 10 particularly in applications where importance is attached to adhesiveness.

Other acid anhydrides and diamines used in the production of polyimides, for example, 4,4'-oxydiphthalic dianhydride, pyromellitic anhydride, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic acid Dianhydride, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane (B
APPF), 2,2-bis (4-aminophenoxy) hexafluoropropane (BAPF), bis-4- (4-aminophenoxy) phenylsulfone (BAPS), bis-4- (3-aminophenoxy) phenylsulfone ( BAPSM) or the like can be added in a small amount as long as the properties are not impaired.

It is important that the amount ratio of each component is within the above range. If α, ω-bis (3-aminopropyl) polydimethylsiloxane is less than 5 mol% of all amine components, low moisture absorption characteristics are obtained. When it does not appear and exceeds 50 mol%, the glass transition temperature is remarkably lowered, and there is a problem in heat resistance. The molar ratio of 2,2-bis (4- (4-aminophenoxy) phenyl) propane is preferably from 10 mol% to 90 mol% of the total amine component, and if it exceeds the above range, the solubility and heat resistance may be increased. A problem arises in sex.

By adding dimethylphenylenediamine, the heat resistance can be improved without lowering the solubility in low-boiling solvents. As dimethylphenylenediamine, 2,5-dimethyl-p-phenylenediamine, 2,4
-Dimethyl-m-phenylenediamine is preferred. When low-temperature bonding is required for adhesives, 1,3-bis (3-
It is effective to add aminophenoxy) benzene.

When the polyimide resin is used as an adhesive, by controlling the molecular weight by end-capping the molecular terminals, it is possible to obtain a melt viscosity suitable for adhesion to an adherend, improve wettability, Adhesive strength can be increased. The amount ratio of the acid anhydride or the aromatic amine as the endcapping agent is preferably in the range of 1 mol% to 5 mol%. If it is less than 1 mol%, the molecular weight becomes too high, so that the solubility in low-boiling solvents, which is a feature of the present invention, is lowered. If it exceeds 5 mol%, the molecular weight is remarkably reduced, and a problem occurs in heat resistance.

The end capping agent is represented by the general formula (1)
And an aromatic amine represented by the general formula (2). Examples of acid anhydrides include phthalic anhydride, maleic anhydride, and nadic anhydride; and aromatic amines include p-methylaniline, p-methoxyaniline,
p-phenoxyaniline and the like are used.

The equivalent ratio between the acid component and the amine component in the polycondensation reaction is an important factor that determines the molecular weight of the resulting polyamic acid. It is well known that there is a correlation between the molecular weight and physical properties of a polymer, especially the number average molecular weight and mechanical properties. The higher the number average molecular weight, the better the mechanical properties. Therefore, in order to obtain practically excellent strength, it is necessary to have a high molecular weight to some extent. In the present invention,
When the equivalent ratio r between the acid component and the amine component is 0.900 ≦ r ≦ 1.06, more preferably 0.975 ≦
It is preferable that r ≦ 1.06. Here, r = [equivalent number of all acid components] / [equivalent number of all amine components]. r is 0.
If the molecular weight is less than 900, the molecular weight is low and brittle, so that the adhesive strength is weak. If it exceeds 1.06, unreacted carboxylic acid may be decarbonated during heating to cause gas generation and foaming, which may be undesirable.

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,
And 1,4-dioxane. 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 nonpolar solvent is 30% by weight or more, the dissolving 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 subjected to thermal dehydration cyclization in an organic solvent to obtain 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, and the system is removed from the system using a device such as a Dean-Stark tube. To be discharged. Dichlorobenzene is known as an organic solvent incompatible with water,
For the purpose of electronics, the above-mentioned aromatic hydrocarbon is preferably used because there is a possibility that a chlorine component may be mixed.
Further, it does not prevent the use of compounds such as acetic anhydride, β-picoline, and pyridine as a catalyst for the imidization reaction.

In the present invention, the higher the degree of imide ring closure, the better the degree of imidization. If the rate of imidization is low, imidization occurs due to heat during use to generate water, which is not preferable. Therefore, 95% or more, more preferably 98% or more Is preferably achieved.

In the present invention, the obtained polyimide solution can be used as it is as a coating varnish. Also,
The polyimide solution can be put into a poor solvent to reprecipitate and precipitate the polyimide resin, remove unreacted monomers, purify, and dry to use 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, 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. 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. However, the polyimide resin is dissolved in an organic solvent to form a resin varnish for coating and dipping, cast into a film, and solid-state for extrusion molding. It can be used as an insulating material, an adhesive film or the like that has both heat resistance and workability.

[0020]

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 has excellent heat resistance and thermosetting properties accompanied by a chemical reaction. Molding can be performed 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.

[0021]

【Example】

Example 1 A dehydrated and purified NMP762 was placed in a four-necked flask equipped with a dry nitrogen gas inlet tube, a cooler, a thermometer, and a stirrer.
g and stir vigorously for 10 minutes while flowing nitrogen gas. Next, 49.2618 g (0.120 mol) of 2,2-bis (4- (4-aminophenoxy) phenyl) propane (BAPP) and 16.3435 g (0.12 mol) of 2,5-dimethyl-p-phenylenediamine (DPX) were used.
0 mol) and 133.9200 g of α, ω-bis (3-aminopropyl) polydimethylsiloxane (APPS) (average molecular weight 837.0
(0, 0.160 mol), heat the system to 60 ° C and stir until uniform. After dissolving uniformly, phthalic anhydride 2.926
4 g (0.020 mol) was added and the mixture was stirred for 1 hour. Thereafter, the system was cooled to 5 ° C. in an ice water bath, and 99.2710 g (0.320 mol) of 4,4′-oxydiphthalic dianhydride, pyromellitic anhydride 1
5.2686 g (0.070 mol) was added in the form of powder over 15 minutes, and 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 191 g of toluene was added to the system. The system was heated to 175 ° C. instead of an oil bath, and the generated water was removed from the system. After heating for 4 hours, 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, 80
Dry under reduced pressure at 12 ° C for 12 hours to remove the solvent, and 287.22 g (90.6
%) Of a solid resin was obtained. The infrared absorption spectrum was measured by the KBr tablet method.
μm absorption, but 6.06 μm
No absorption could be recognized, confirming that this resin was almost 100% imidized.

It was confirmed that the polyimide resin thus obtained was well dissolved in cyclohexanone / toluene (90/10 w / w%). At this time, the molar ratio of the acid and the amine was a / (a + b + 0.5f) = 0.8 and b /
(A + b + 0.5f) = 0.175, e / (c + d + e) = 0.
4

(Examples 2 to 4) In the same manner as in Example 1,
The reaction was carried out according to the formulation shown in Table 1 to obtain a soluble polyimide resin. Table 1 shows the evaluation results obtained for these polyimide resins. It can be seen that all of them have excellent solubility in organic solvents.

[0025]

[Table 1]

In Table 1, ODPA is 4,4'-oxydiphthalic dianhydride, PMDA is pyromellitic anhydride, and BAPP is 2,2-bis (4- (4-aminophenoxy) phenyl). Propane, APB is 1,3-bis (3-aminophenoxy) benzene, DPX is 2,5-dimethyl-p-phenylenediamine, and APPS is α, ω-bis (3-aminopropyl) polydimethylsiloxane. And PPA are shorthands for p-phenoxyaniline.

The numerical values of the blending are the blending equivalent ratio of each component, and the water absorption is 168% under the environment of 85 ° C. and 85% RH.
The saturated water absorption after standing for a period of time (HH-168 treatment)
The generated moisture is a value obtained by quantifying the gas generated when heated at 250 ° C. for 15 minutes by the GC-MS method, and the water content is determined by the Karl Fischer method. S in the column of solubility indicates that the compound is dissolved in the corresponding solvent.

Comparative Example 1 According to the composition shown in Table 2, the reaction was carried out under the same conditions as in Example 1 to obtain a polyimide resin. An attempt was made to dissolve this resin in cyclohexanone, but the resin was in a swollen gel state and could not be completely dissolved. In addition, the same condition was applied to DMF and DMAC, and a resin varnish could not be prepared.

(Comparative Examples 2 to 4) As in Example 1, the second
Table 2 shows the results of evaluation of the polyimide resins obtained by reacting with the formulations shown in the table.

[0030]

[Table 2]

In Table 2, PPDA is an abbreviation for p-phenylenediamine, and I in the solubility column indicates that it is insoluble in the corresponding solvent.

The above examples show that the present invention can provide a polyimide resin which is soluble in an organic solvent and is excellent in heat resistance and low moisture absorption.

[0033]

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, the residual solvent can be almost completely eliminated, and since it has already been imidized, a high temperature process for imidization is not required during processing, and no water is generated. For this reason, it is extremely useful industrially as a material for electronics requiring high reliability and heat resistance.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 73/00-73/26 C08J 179/00-179/08 C08L 79/00-79/08 CA (STN)

Claims (2)

(57) [Claims] 1. A mole of 4,4'-oxydiphthalic dianhydride and b mole of pyromellitic anhydride are used as acid components, and c-mol of 2,2-bis (4- (4-aminophenoxy) phenyl) propane is used. And d-mol of one or two kinds of diamines selected from the group of 1,3-bis (3-aminophenoxy) benzene and dimethylphenylenediamine, and α, ω-bis (3-aminopropyl)
3 to 4 components consisting of e-mol polydimethylsiloxane
And the molar ratio of a, b, c, d, and e is
a / (a + b) ≧ 0.8, b / (a + b) ≦ 0.2, and
A polyimide resin that is soluble in an organic solvent in which both components are reacted at a ratio of 0.05 ≦ e / (c + d + e) ≦ 0.5 to close the imide. 2. A mole of 4,4′-oxydiphthalic dianhydride and b mole of pyromellitic anhydride are used as acid components, and 2,2-bis (4- (4-aminophenoxy) phenyl) propane c mole And d-mol of one or two kinds of diamines selected from the group of 1,3-bis (3-aminophenoxy) benzene and dimethylphenylenediamine, and α, ω-bis (3-aminopropyl)
3 to 4 components consisting of e-mol polydimethylsiloxane
And the end of the polyimide resin is capped with f mol of an acid anhydride represented by the general formula (1) or g mol of an aromatic amine represented by the general formula (2). , C, d, e, f, g have a molar ratio of a / (a
+ B + 0.5f) ≧ 0.8, b / (a + b + 0.5f) ≦ 0.2,
0.01 ≦ f / (a + b + 0.5f) ≦ 0.05, 0.01 ≦ g /
(C + d + e + 0.5g) ≦ 0.05, 0.05 ≦ e / (c + d
+ E + 0.5g) ≦ 0.5 and either f or g is 0, and the two components are reacted at a ratio of 0 to form a polyimide resin which is soluble in an organic solvent which is imide-closed. Embedded image (Wherein X is At least one group selected from the group consisting of: (Wherein, Y is a hydrogen atom or at least one group selected from methyl, ethyl, propyl, butyl, phenyl, methoxy, ethoxy, propoxy, butoxy, or phenoxy groups)