JPH0423833A - Polyimidosiloxane and its composition - Google Patents

Abstract

PURPOSE:To obtain a polyimidosiloxane useful as an electrical insulating protecting film, having heat resistance and electrical characteristics, by reacting a specific aromatic tetracarboxylic acid component with a specific diamine component and imidating. CONSTITUTION:(A) An aromatic tetracarboxylic acid component comprising a 2,3,3',4'-biphenyltetracarboxylic acid [preferably 85-100mol%] is polymerized with (B) an equimolar amount of (i) 45-80mol% (preferably 50-75mol%) diaminopolysiloxane shown by the formula (R1 is bifunctional hydrocarbon residue; R2 is 1-3C alkyl or phenyl; (l) is 3-30) and (ii) 20-55mol% (preferably 50-25mol%) aromatic diamine in an organic polar solvent and imidated to give the objective polyimidosiloxane. The polyimidosiloxane is uniformly dissolved in an organic solvent (preferably methyl diglyme) having >=140 deg.C boiling point to give a solution composition.

Description

Detailed Description of the Invention [Industrial Application Field] This invention provides a tetracarboxylic acid component whose main component is 2.3.3',4''-biphenyltetracarboxylic acid or its acid dianhydride; Specific diamino polysiloxane 45
-80 mol% and a diamine component consisting of 20-55 mol% of aromatic diamine, and related to a special polyimide siloxane having solubility, heat resistance, and non-curling properties, and the above-mentioned polyimide siloxane. This relates to a solution composition (printing ink, coating face) that is uniformly dissolved in a specific organic solvent and can form a protective film on a flexible wiring board by screen printing or the like.

[Description of the Prior Art] The use of aromatic polyimide as an electrically insulating protective film is useful for, for example, insulating films for solid-state devices, passivation films, semiconductor integrated circuits, glabella insulating films for flexible wiring boards, etc. Various applications are already known.

However, since aromatic polyimide is generally difficult to dissolve in organic solvents, it is used as a solution of aromatic polyimide precursor (aromatic polyamic acid) to form a coating film, and then dried and imidized. It is necessary to form a protective film of aromatic polyimide by heat treatment at a considerably high temperature for a long time, and there is a problem that the electrical or electronic components themselves to be protected are thermally degraded.

On the other hand, as aromatic polyimides soluble in organic solvents, for example, polyimides such as those described in Japanese Patent Publication No. 57-41491 are known. Since the adhesion (adhesiveness) to the substrate was not sufficient, it was necessary to treat the substrate etc. with an adhesion promoter in advance.

In order to solve the above-mentioned problems, a precursor of polyimidosiloxane using diamino polysilicon as a diamine component has been proposed, for example, in JP-A-57-143328,
Although disclosed in JP-A-58-13631, these polyimidosiloxane precursors had the disadvantage that the coating film had to be treated at high temperature in order to imidize the polymer.

Also, JP-A-61-118424 and JP-A-61
Soluble polyimidosiloxanes are disclosed in JP-A-207438, JP-A-63-225629, and JP-A-1-121325. However, each of these polyimidesiloxanes has manufacturing problems in that the manufacturing process involves several steps and takes a long time to manufacture, and it does not contain any aromatic diamine as an amine component, so it has low heat resistance. The problem is that the solubility in various organic solvents is not necessarily sufficient, or
When an organic solvent solution of these polymidosiloxanes is applied onto a flexible copper-clad substrate and dried, there is a problem in that the flexible substrate curls significantly.

[Problems to be solved]

The object of the present invention is to provide a polyimide siloxane that has high solubility in organic solvents, the necessary heat resistance, and non-curling properties when a protective film is formed, and that can be easily produced. It is to make offerings.

[Means to solve problems]

The first invention of the present application provides: (a) 2+313'+4'-hyphenyltetracarboxylic acids (preferably 2,3.3',4'-biphenyltetracarboxylic acid or its acid dianhydride, or its acid esterified product) as the main component (preferably 80%
an aromatic tetracarboxylic acid component (containing at least 85 to 100 mol %); (b) i) 45 to 80 mol % (preferably 45 to 75 mol %) of a diamino polysiloxane represented by the following general formula I;
In particular, by polymerizing and imidizing a diamine component consisting of 50 to 75 mol%) and ii) 20 to 55 mol% (preferably 25 to 55%, especially 50 to 25 mol%) of aromatic diamine. The present invention relates to the obtained polyimidesiloxane.

(In the formula, R represents a divalent hydrocarbon residue, Rt independently represents an alkyl group having 1 to 3 carbon atoms or a phenyl group, and l
represents an integer of 3 to 30, preferably 4 to 20. ) Further, the second invention of the present application provides that the polyimidosiloxane represented by the general formula I has a boiling point of 140°C or higher (preferably a boiling point of 145 to 300°C, particularly a boiling point of 150 to 280°C).
) A polyimidesiloxane composition (solution composition) that is uniformly dissolved in an organic solvent (preferably an organic polar solvent).

Examples of the polyimidosiloxane represented by General 2 of this invention include phenolic solvents, amide solvents (pyrrolidone solvents, formamide solvents, acetamide solvents, etc.), oxane solvents (dioxane, trioxane, etc.), and glyme solvents. It has sufficient solubility in organic polar solvents (such as methyl toglyme and methyl triglyme), and has a relatively low viscosity from the polyimido siloxane and the organic polar solvent (for coating). can be easily prepared.

Further, the polyimidosiloxane of the present invention substantially does not cause curling when a solution composition thereof is applied onto a substrate such as a silicon wafer or a flexible wiring board and dried to form a protective film. The protective film has excellent adhesion to each of the substrates mentioned above, and there is no need to pre-treat the substrate with an adhesion promoter such as a silane coupling agent. A protective film can be formed for applications such as films and junction coats for diodes without performing the above pretreatment.

In the composition of this invention, the organic solvent has a boiling point of 1
When using an organic solvent (such as methyl triglyme) with a temperature of 80°C or higher, especially 200°C or higher, the dissipation due to evaporation of the solvent is extremely reduced, improving storage stability and forming the above-mentioned protective film. Solution composition for (
This method is optimal because it facilitates the preparation (roll kneading, etc.) of the printing ink (printing ink), and it allows silk screen printing to be carried out suitably without any problems using the printing ink.

Furthermore, the polyimide siloxane of the present invention has excellent mechanical strength and electrical insulation, and also has high heat resistance, so it can be used as a surface protective film or interlayer of various electrical or electronic components (especially flexible wiring boards). It can be suitably used as an insulating film or the like.

Polyimide siloxane composition (solution composition) of this invention
is applied to the surfaces of various electrical or electronic components such as flexible wiring boards by known means, and then dried and heat-treated at a relatively low temperature to form an excellent protective film (thickness:
(approximately 0.5 to 500 μm).

The method for producing the polyimidosiloxane of the present invention includes, for example, (a) an aromatic tetracarboxylic acid component mainly containing 2.3.3+ 14+-biphenyltetracarboxylic acids; Diaminopolysiloxane shown (wherein ! is 3 to 30) 45
~80 mol%, and ii) aromatic diamine 20-5
A method for producing polyimidosiloxane by heating approximately equimolar amounts of a diamine component consisting of 5 mol% to a high temperature of 120° C. or higher in an organic polar solvent, and polymerizing and imidizing it in one step, or The above two components were mixed in approximately equimolar amounts in an organic polar solvent at 80°C.
A method of producing polyimidesiloxane by polymerizing at the following low temperature to produce polyamic acid (polyimide precursor), and imidizing the polyamic acid under appropriate conditions (chemical imidization or imidization by high-temperature heating). can be mentioned.

In the above-mentioned aromatic tetracarboxylic acid component, it is used together with 2,3.3°,4°-biphenyltetracarboxylic acids in a proportion of 20 mol% or less, particularly 15 mol% or less, based on the total tetracarboxylic acid component. "Other aromatic tetracarboxylic acid compounds 1 include 3.3',
4.4'-biphenyltetracarboxylic acid, 33", 4,
4”-benzophenonetetracarboxylic acid, 3°3”, 4
．． Examples include 4''-biphenyl ether tetralponic acid, pyromellitic acid, dianhydrides of these acids, and esters of these acids.

As the diaminopolysiloxane represented by the general formula I, R1 in the general formula I is a divalent hydrocarbon residue consisting of a plurality of methylene groups or phenylene groups having 2 to 6 carbon atoms, particularly 3 to 5 carbon atoms. and R2 is independently an alkyl group having 1 to 3 carbon atoms such as a methyl group, ethyl group, or propyl group, or
Preferably, it is a phenyl group, and! is 4-2
It is preferably about 0, especially about 5 to 15.

As the diaminopolysiloxane represented by the above general formula I, for example, compounds represented by the following general formula (l is 4 to 20) can be suitably mentioned.

The aromatic diamine mentioned above is preferably an aromatic diamine compound having a plurality of benzene rings, for example, 4,4
Aromatic diamine compounds having two benzene rings such as ゛-diaminodiphenyl ether, 4゜4゛-diaminodiphenylmethane, 4,4゛-diaminodiphenylsulfone, 0-tolidine, 0-dianisidine, 1,4-bis(
4-aminophenoxy)benzene, 1,4-bis(4-
Aromatic diamine compounds having three benzene rings such as aminophenyl)benzene, or bisC4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis(4
Preferred examples include aromatic diamine compounds having four benzene rings, such as -(4-aminophenoxy)phenyl]propane.

In addition, as the above-mentioned aromatic diamine, in addition to aromatic diamine compounds having two or more benzene rings, aromatic diamines having one benzene ring may be used in an amount of 20 mol% or less, particularly 16 mol% or less, based on the total aromatic diamine. It is also possible to use group diamine compounds in combination, and examples of such aromatic diamine compounds with one benzene ring include para-phenylene diamine, meta-phenylene diamine, 2,4-diaminotoluene, and 3,5-diaminobenzoin. acid, 2,6-diaminobenzoic acid, 3,5-diaminobenzyl allylate, and the like.

In the polyimide siloxane of the present invention, if the content ratio of "the main chain unit based on diamino polysiloxane" to the total diamine component becomes too small, the solubility of such polyimide siloxane may decrease or When a siloxane solution is used to form a protective film on a flexible wiring board, it is not suitable because it curls significantly. If it is too high, the heat resistance, mechanical properties, etc. of the polymer will deteriorate, so it is not suitable.

Examples of the organic polar solvent used in the above method for producing polyimidosiloxane include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N
- Formamide solvents such as dimethylformamide, N,N-diethylformamide, acetamide solvents such as N,N-dimethylacetamide, N,N-diethylacetamide, N-methyl-2pyrrolidone, N-ethyl-2
- Pyrrolidone solvents such as pyrrolidone and N-vinyl 2-pyrrolidone, glyme solvents such as methyl diglyme and methyl tridiclime, hexamethylene phosphoramide, T-butyllactone, cyclohexanone, etc., or phenol, o-lm- Alternatively, phenolic solvents such as p-cresol, xylenol, halogenated phenols (parachlorophenol, parabromophenol, etc.), catechol, etc. can be mentioned.

The polyimidosiloxane of this invention is preferably a high molecular weight polymer, for example, concentration: 0.5 g
/ 100m j! (N-methyl-2-pyrrolidone), the logarithmic viscosity (indicating the degree of polymerization of the polymer) measured at a measurement temperature of 30°C is 0.0.
It is preferably about 5 to 3, especially about 0.1 to 2, and the imidization rate of the polyimidosiloxane (ratio of r imide bonds 1 by infrared absorption spectroscopy) is
It is preferably about 90% or more, particularly 95 to 100%, and substantially no absorption peak of "amide-acid bond" is found in an IR chart.

Polyimide siloxane composition (solution composition) of this invention
As the organic solvent used in the step, the organic polar solvent used in the above-mentioned method for producing polyimidosiloxane can also be suitably used. may have been done.

The composition of the present invention also includes wollastonite, silica,
Inorganic fillers such as talc, polymer fillers, or
It may also contain inorganic or organic dyes.

The polyimidosiloxane composition of the present invention has a concentration of the aforementioned polyimidosiloxane of 5 to 50% by weight, particularly 10% by weight.
It is preferable that the content is 40% by weight, and the solution viscosity at 25°C (rotational viscosity) is 0°01 to 10000 voids,
In particular, it is preferably 0.1 to 1000 poise.

The polyimidosiloxane composition of the present invention is obtained by directly polymerizing and imidizing an aromatic tetracarboxylic acid component and a diamine component in an organic polar solvent as described above. Alternatively, the polymerization solution may be diluted to an appropriate concentration with an organic solvent similar to the polymerization solvent.

Alternatively, the polyimidosiloxane composition can also be prepared by precipitating and isolating a powdered polyimidosiloxane from the above polymerization solution, and uniformly dissolving the isolated polyimidosiloxane powder in an organic solvent.

The polyimide siloxane composition of the present invention can be applied to the surface of the object to be coated (flexible circuit board, semiconductor, etc.).
The solution composition is coated to a uniform thickness by using a rotary coating machine, a dispenser, a printing machine, etc. at room temperature or under heating. A solidified film (protective film) of polyimidosiloxane can be formed by drying at a temperature of 60 to 250° C. or higher, particularly about 60 to 250° C.

[Example] The present invention will be described in more detail with reference to Examples and Comparative Examples below.

Each test method in Examples and Comparative Examples is as follows.

The solubility of polyimidosiloxane is as follows: 0.2g of polyimidosiloxane powder is mixed with 0.8g of methyl diglyme at 20°C.
g, leave it to stand, observe the state of dissolution,
◎ if it dissolves within hours, O if it dissolves within 1 day △ if the solvent simply swells in the polymer
, and cases where it was completely insoluble even for one week were indicated by ×.

The thermal decomposition initiation temperature of polyimide siloxane is determined by DuPont 9
51 thermogravimeter.

The mechanical strength of polyimide siloxane is 2
A 30% polymer solution was cast onto the glass plate using a 00 μm spacer as a frame to form a thin film, and the thin film was heated at 80°C for 30 minutes, 150°C for 30 minutes, and 200°C. The polyimide siloxane film was dried and heat-treated for 30 minutes to form a film with a thickness of about 50 μm, and then tested using a universal tensile tester (manufactured by Orientic Co., Ltd., Tensilon tJTM-11-20).
Breaking strength, elongation, and initial elasticity were measured.

A warpage test when polyimidosiloxane was applied to an aromatic polyimide film was performed using a 75 μm thick aromatic polyimide film (manufactured by Ube Industries, Ltd., UP I LEX 5-
75) A PET spacer with a thickness of 100 μm is placed on top of the polyimide siloxane solution composition in the area surrounded by the spacer.
Barcode with coach-in-blond to form a coating layer of the solution composition, and finally, coat the coating layer on the substrate with 8
30 minutes at 0℃, 30 minutes at 150℃, and 200℃
After drying and heat treatment (hake) for 30 minutes, a protective film made of polyimide siloxane (average thickness = 40 μm) was formed.
was formed. Then, the "curvature radius" of the obtained polyimide film (length: 100 mm x width: 50 am) on which the protective film was formed was measured.

Example 1 [Production of polyimidesiloxane] Capacity 2! 2.3. into a glass separable flask.
3',4'-biphenyltetracarboxylic dianhydride (a
-BPDA) 147.2 (500 mmol) and N-methyl-2-pyrrolidone (NMP) 1274 g were added to dissolve a-BPDA, and while stirring the solution at room temperature, diaminopolysiloxane (NMP) was added. AP
S) [Manufactured by Shin-Etsu Silicon ■, X-22-161AS,
R: -((:Hl)3-1Rt: methyl group, f=9
) A solution consisting of 304.9 g (346.5 mmol) and 530 g of diglyme was added over 30 minutes, and the mixture was heated at a polymerization temperature of 190° C. while passing nitrogen gas and while refluxing the methyl diglyme to remove water. 2,2-bis(4
-(4-aminophenoxy)phenyl]propane (BA
PP) 62.19g (151°25 mmol) and NMP
Add a solution of 500 g dropwise over 30 minutes, react at a reaction temperature of 200 to 210°C for 6 hours, and finally,
The reaction solution was added to 202 methanol and precipitated for 30 minutes using a disperser, and the polymer powder was isolated by polymer filtration.
Washing for 0 minutes was carried out twice, followed by vacuum drying at 60° C. for 8 hours to obtain 428.9 g of polyimide siloxane powder.

The polyimide siloxane obtained as described above had a logarithmic viscosity (30° C.) of 0.24 and an imidization rate of substantially 100%.

[Preparation of solution composition of polyimidosiloxane] 3.5 g of the polyimidosiloxane produced as described above is dissolved in 7 g of methyl diglyme at room temperature to obtain a polymer concentration such that the polyimidosiloxane is uniformly dissolved in the methyl diglyme. A solution composition of 35% by weight polyimidosiloxane was prepared.

The solution composition had a solution viscosity (rotational viscosity) of 3500 centipoise at 25°C.

[Coating operation of solution composition: Formation of protective film] Thickness: 75 μm
Aromatic polyimide film (manufactured by Ube Koish, UP
A 100 μm thick polyethylene phthalate (PET
) is placed, and the solution composition of the polyimide siloxane is barcoded with a laboratory coat-in-blonde (No. 3) within the area surrounded by the spacer. A coating layer is formed, and finally, the coating layer on the substrate is heated at 80° C. for 30 minutes at 150° C.
It was dried and heat-treated (baked) at 180° C. for 30 minutes and 180° C. for 30 minutes to form a protective film (average thickness 2408 m) made of polyimide siloxane.

The flexible wiring board on which the protective layer is formed has substantially no curl, and the adhesion between the protective layer and the wiring board is determined by an eye test (peeling with adhesive tape). There were no problems at all, and the two were firmly attached.

In a separate warpage test, the polyimide film on which the protective film was formed had an r-curvature radius of 100 an or more, and was in a state where there was substantially no warpage (no warpage).

Examples 2 to 4 and Comparative Examples 1 to 4 As the aromatic tetracarboxylic acid component, aromatic tetracarboxylic acid compounds of the types shown in Table 1 were used, and as the diamine component, the types and amounts (moles) shown in Table 1 were used. Polyimidosiloxane (imidization rate = 95%) was prepared in the same manner as in Example 1, except that diaminopolysiloxane of
above) were manufactured respectively.

Table 1 shows the logarithmic viscosity, heat resistance, solubility, and mechanical properties of these polyimidesiloxanes.

Note that the polyimidosiloxanes obtained in Comparative Examples 1 and 2 are substantially insoluble in organic solvents such as NMP and dioxane, so it is not possible to prepare a solution composition of polyimidosiloxanes, and therefore, these films cannot be prepared. It was not possible to measure mechanical properties or perform warpage tests.

In addition, the polyimidosiloxanes obtained in Comparative Examples 3 and 4 do not dissolve sufficiently in methyl diglyme.
A solution composition of polyimidosiloxane was prepared using solvent: NMP to form a film of polyimidosiloxane, and the mechanical properties of the film were measured.

A polyimidosiloxane solution composition (polymer concentration:
% by weight) were prepared respectively.

Table 1 shows the solution viscosity (25°C) of each solution composition.

Except for using each of the above-mentioned solution compositions, the coating operation was carried out in the same manner as in Example 1, and the quality of the coating was observed. Furthermore, a separate warp test was conducted, and the results (the quality of the coating operation, Table 1 shows the warp radius of curvature.

The abbreviations used in Table 1 have the following meanings.

a-BPDA; 2,3+3'+4'-diphenyltetracarboxylic dianhydride PMD^; Pyromellitic dianhydride BTDA i 3,4.3', 4''-benzophenonetetracarboxylic dianhydride BAPP; 2, 2-bis(4-(4-aminophenoxy)phenyl)benzene DAPS; Diaminopolysiloxane (X-2246
1AS) Example 5 In preparing the solution composition, the same procedure as in Example 1 was carried out except that the polyimide siloxane produced in Example 1 was used and methyl triglyme with a boiling point of 216°C was used as the organic solvent. , a solution composition was prepared. The solution composition had a solution viscosity (rotational viscosity) of 4000 centipoise at 25°C.

Using the above solution composition, a screen printing method (
200 mesh, screen thickness 81μm, 11116
µm stainless steel screen), and the coating film was dried and heat treated at 80°C.
for 30 minutes, at 150℃ for 30 minutes, and at 200℃ for 30 minutes.
A protective film (average thickness: 2408 m) was formed on a flexible wiring board in the same manner as in Example 1, except that the heating time was 0 minutes.

The above screen printing can be done well and also
The flexible wiring board on which the protective layer was formed was substantially free of curls as in Example 1, and the adhesion between the protective layer and the wiring board was also good.

In addition, in a warpage test conducted separately using the solution composition, the polyimide film on which the protective film was formed was 1
The warpage radius of curvature was 100 degrees or more, and there was substantially no warpage (no warpage).

[Actions and effects of the present invention]

The polyimidosiloxane of this invention is a flexible polymer with a fairly high proportion of diaminopolysiloxane-based constituent units, so it retains heat resistance, electrical properties, and mechanical properties, and is resistant to organic solvents. Polyimidosiloxane has extremely excellent solubility (especially solubility in methyldiglyme and methyltriglyme), and is obtained by uniformly dissolving the polyimidesiloxane in an organic solvent such as methyldiglyme or methyltriglyme. A solution composition is applied onto an aromatic polyimide film used for substrates such as flexible wiring boards, dried and heat-treated to form a heat-resistant and electrically insulating protective film that firmly adheres to the substrate. is possible,
In this case, the substrate is substantially not warped.

Patent applicant: Ube Industries Co., Ltd.

Claims (2)

[Claims] (1) An aromatic tetracarboxylic acid component mainly composed of 2,3,3',4'-biphenyltetracarboxylic acids and a diamino polysiloxane 45 represented by the following general formula I
A polyimidosiloxane obtained by polymerizing and imidizing 80 mol% and a diamine component consisting of 20 to 55 mol% of an aromatic diamine. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R_1 represents a divalent hydrocarbon residue, R_2 independently represents an alkyl group or phenyl group having 1 to 3 carbon atoms, and l represents 3 Indicates an integer between ~30.) (2) A polyimidosiloxane composition in which the polyimidosiloxane according to claim 1 is uniformly dissolved in an organic solvent having a boiling point of 140° C. or higher.