JPH08218034A - Polyimide-based heat-resistant coating agent composition - Google Patents

Abstract

PURPOSE: To obtain a new composition having excellent heat-resistance, chemical resistance, adhesivity and electrical characteristics and useful for heat-resistant coating material, coating agent for electronic material, etc., by compounding a polyimide resin soluble in an organic solvent with a specific amount of a silane-based curable compound. CONSTITUTION: This composition is produced by compounding (A) 100 pts.wt. of a polyimide resin soluble in an organic solvent and composed of (i) 1-80mol% of a recurring unit of formula I (Ar1 is a tetravalent organic group; R1 and R2 are each single bond, a 1-4C alkylene or phenylene; R3 to R7 are each methyl or phenyl; (m) and (n) are each 1-10) and (ii) 99-20mol% of a recurring unit of formula II (Ar2 is a tetravalent organic group; Ar3 is a bivalent organic group having >=3 aromatic rings) with (B) 1-200 pts.wt. of a curable compound of formula III ((l) is 1-10 on an average).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyimide heat resistant coating composition which is excellent in heat resistance, chemical resistance, adhesiveness and electric characteristics, The present invention relates to a polyimide resin heat-resistant coating composition which is useful as a heat-resistant paint and a coating agent for electronic materials.

[0002]

2. Description of the Related Art Polyimide has excellent heat resistance and mechanical properties and is widely used as a film, a coating agent or a molding material. In addition, for the purpose of imparting electrical properties and adhesiveness to these polyimide resins, many siloxane-modified polyimide resins, which are copolymers of soft segments such as diaminopolysiloxane, have been developed, and protective films for semiconductors, insulating films, etc. It is widely used in the field of electronic materials such as cover coating agents for circuit materials. (JP-A-6
0-76533, JP-A-62-226228). When using these resins, since the polyimide resin is generally insoluble in an organic solvent, it is common to form a polyimide resin coating film by applying a polyamic acid that is its precursor and then performing an imidization reaction by heating or the like. Has been done in. Also,
Since these resin solutions tend to have high viscosities depending on the monomer species, it is common to reduce the monomer concentration at the time of preparation or to dilute them with an organic solvent, etc., as a method for controlling the viscosity to an appropriate level that can be used. Is.

However, the method of imidizing after applying polyamic acid has a drawback that water is generated during the ring-closing reaction and the treatment is carried out at a high temperature of 200 ° C. or higher, which damages the substrate or metal. Was. Further, in the above viscosity adjustment, the solid content concentration in the solution inevitably becomes low due to solvent dilution, so that the resulting coating film is unlikely to be a thick film, and further lacks flatness, so that particularly insulating properties are required. There was a problem that the part was difficult to use. As means for solving such a problem, Japanese Patent Laid-Open No. 4-10
Although it is possible to use an organic solvent-soluble polyimide resin as disclosed in No. 8880, since these resins have a low glass transition temperature and are soluble in an organic solvent, heat resistance after forming a coating film is high. However, there is a problem of poor chemical resistance.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and has a higher heat resistance than conventional heat-resistant coating agents.
It is intended to provide a novel polyimide resin heat resistant coating composition which is excellent in chemical resistance, adhesiveness and electric characteristics.

[0005]

That is, the present invention is
(A) The following general formula (1)

[Chemical 4] And a repeating unit represented by the following general formula (2):

Embedded image With respect to 100 parts by weight of an organic solvent-soluble polyimide resin consisting of 99 to 20 mol% of a repeating unit represented by
(B) The following general formula (3)

[Chemical 6] 1 to 200 parts by weight of the curable compound represented by 1. In these compositions, the vinyl group in the polyimide resin and the curable compound undergo a hydrosilylation reaction to form a crosslinked structure, whereby the heat resistance and chemical resistance of the resulting coating film can be improved.

Ar ₁ in the repeating unit represented by the general formula (1) is a tetravalent organic group, and the tetracarboxylic acid anhydride which constitutes this group is soluble in an organic solvent system. To give, specifically, 3,
3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,
3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3',
4,4'-diphenyl ether tetracarboxylic dianhydride,
3,3 ', 4,4'-Diphenylsulfone tetracarboxylic acid dianhydride, 2,2'-bis (3,3', 4,4'-tetracarboxyphenyl) tetrafluoropropane dianhydride, 2,3 ', 3', 4'-benzophenone tetracarboxylic dianhydride, 2,3 ', 3', 4'-
Biphenyl tetracarboxylic dianhydride, 2,3 ', 3', 4'-diphenyl ether tetracarboxylic dianhydride, 2,3 ', 3',
4'-diphenylsulfone tetracarboxylic dianhydride, 2,
Tetra having at least two aromatic rings such as 2'-bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride and 2,2'-bis (3,4-dicarboxyphenoxyphenyl) sulfone dianhydride It is desirable to use a carboxylic acid dianhydride, as a part of the total tetracarboxylic acid dianhydride amount, pyromellitic dianhydride, 1,4,5,8-naphthalene tetracarboxylic acid dianhydride, 2,3, 6,7-naphthalenetetracarboxylic dianhydride and the like can also be used.

Further, the siloxane-based diamine component for constituting the repeating unit represented by the general formula (1) may be one having one vinyl group in the molecule, and specifically, the following general formula

[Chemical 7] Compounds (A) to (F) represented by are listed below, but as long as they have at least one vinyl group as a side chain substituent, they can be used without limitation. Further, these may be used alone or in combination of two or more.

The tetracarboxylic acid anhydride for constituting Ar _{2 in the} repeating unit represented by the general formula (2) is used for constituting Ar ₁ in the general formula (1). The same thing as the tetracarboxylic acid anhydride can be illustrated.

The diamine component for forming Ar ₃ includes 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 2,2 [4-bis (3-aminophenoxy) phenyl]. Propane, bis- [4- (4-aminophenoxy) phenyl] sulfone, bis- [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane, 2, 2-bis (3-aminophenoxyphenyl) hexafluoropropane, 4,4'-bis (4-aminophenoxy) diphenyl, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (3-amino Examples thereof include phenoxy) benzene, but a diamino compound having at least three aromatic rings is used. The number of aromatic rings is 2
If the number is less than or equal to the number, the polyimide resin obtained by polymerization becomes difficult to dissolve in an organic solvent, and it is difficult to use in the intended use.

In addition to the above diamine component, 4,
4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,
4'-diaminodiphenyl sulfide, 4,4'-diaminobenzanilide, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 1,4-diaminobenzene, 2,5-diaminotoluene, etc. A diamino compound having an aromatic ring can be used in combination as a part.

The proportion of the general formula (1) in the polyimide is 1 to
It is 80 mol%, but when the ratio of (1) is less than 1 mol%, there are few groups involved in the hydrosilylation reaction,
This is because if it exceeds 80 mol%, the strength and heat resistance of the resin itself will decrease due to an increase in the siloxane component in the polyimide. Further, in order to stably maintain the long-term heat resistance and chemical resistance of the composition, the ratio of the general formula (1) is 10 to 5
0 mol% is preferable.

The organic solvent-soluble polyimide resin of the present invention can be obtained by polymerizing the monomer component forming the above repeating unit in the presence of an organic solvent. It is desirable that the organic solvent has a sufficient dissolving power for the monomer component used in the reaction and the polyimide produced. Preferable specific examples of the organic solvent include N-methyl-2-pyrrolidone (NMP) and N, N-dimethylacetamide (DMA
c), N, N-dimethylformamide (DMF), N, N-
Diethylformamide, N, N-diethylacetamide,
Examples thereof include dimethyl sulfoxide (DMSO), and it is preferable to use NMP or DMAc from the viewpoint of thermal stability of the solvent.

The azeotropic solvent used to remove the water generated during the imidization reaction is an aromatic hydrocarbon compound such as benzene, toluene, xylene, or tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether. (Diglyme), dioxane, methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, γ-butyrolactone, cyclohexanone, and other ether-based, ester-based, or ketone-based solvents, which may be used alone or in combination of two or more components. Although it can be used as a mixed solvent, diglyme or ethyl cellosolve acetate is more preferable for continuously performing dehydration.

The polyimide resin relating to the heat resistant coating agent of the present invention is synthesized, for example, as follows using the above raw materials and reaction solvent. The tetracarboxylic acid anhydride X component and the diaminopolysiloxane Y component having a vinyl group as a side chain substituent are reacted in the above organic solvent, and then the aromatic diamine Z component is added and reacted to give a polyimide precursor. To obtain a polyamic acid. The molar ratio X / (Y + Z) between the tetracarboxylic acid anhydride and the diamine component is preferably around the equivalent, particularly in the range of 0.9 to 1.1.
If the molar ratio exceeds this range, the molecular weight does not increase and heat resistance and mechanical properties deteriorate, which is not preferable. The total solid content concentration of the tetracarboxylic acid anhydride and the diamine component in the reaction solution is 10 to 50% by weight, and preferably 20 to 40% by weight.

The reaction temperature for synthesizing the polyamic acid is
Usually, it is preferably 50 ° C. or lower, particularly 40 ° C. or lower. Further, the reaction time is usually such that the reaction is sufficient for the production of polyamic acid to be completed. Usually 4 to 10 hours is sufficient. The polyamic acid thus obtained is heated and imidized in a reaction solution to obtain a polyimide. In this case, water generated by the heat imidization reaction is removed by continuously distilling it with the azeotropic solvent. The reaction temperature at the time of carrying out the imidization reaction is not particularly limited, but is equal to or lower than the boiling point of the organic solvent used in the reaction, and preferably 200 ° C. or lower. Further, imidization time of 3 to 10 hours is sufficient. The polyimide resin thus obtained has a logarithmic viscosity of 0.1 to 3, measured in an organic solvent such as N-methyl-2-pyrrolidone at a polymer concentration of 0.5 g / dl and a temperature of 30 ° C. 0, preferably 0.2-
It is in the range of 2.0 dl / g.

The polyimide resin obtained by the above method can be used as a coating agent as it is after the completion of the synthesis. Further, the reaction product after completion of the reaction obtained by the above method is added to the poor solvent of polyimide to precipitate the polyimide, and after the polyimide is isolated, it is dissolved in a solvent that dissolves the isolated powdery polyimide. The obtained polyimide solution can also be used as a coating agent. Examples of the solvent used here include the solvents used in the above-mentioned polymerization reaction. Specifically, N-methyl-2-pyrrolidone (NMP), N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF), N, N-diethylformamide, N,
N-diethylacetamide, dimethyl sulfoxide (D
MSO), tetrahydrofuran, dioxane, γ-butyrolactone, cyclohexanone, etc. These organic solvents can be used alone or as a mixed solvent of two or more components.

The heat-resistant coating composition according to the present invention has the following general formula (3) with respect to 100 parts by weight of the organic solvent-soluble polyimide resin.

Embedded image It can be obtained by blending 1 to 200 parts by weight of the curable compound represented by. Specifically, it can be obtained by adding a predetermined amount of this curable compound to a solution prepared by dissolving the polyimide resin in the organic solvent used for synthesizing the polyimide resin. This curable compound has a function of improving heat resistance and chemical resistance when used as a heat resistant coating agent by forming a crosslinked structure by hydrosilylation reaction with a vinyl group in a polyimide resin. However, when the amount of the curable compound is 1 part by weight or less, the groups involved in the hydrosilylation reaction are reduced, and the heat resistance, chemical resistance, and strength of the resulting cured product are not improved. The curable compound in the reaction increases, and the heat resistance and strength decrease.

Platinum catalysts such as chloroplatinic acid, chloroplatinic acid alcohol solution, platinum-olefin complex, platinum-vinylsiloxane complex and the like can be used for the purpose of causing the above-mentioned crosslinking reaction more efficiently. The amount of the platinum-based catalyst used in this cross-linking reaction is within the range of 1 to 100 parts by weight as a catalyst atom with respect to the total amount of the curable compound (3) of 1 million parts by weight. Further, as a catalyst other than the platinum-based catalyst, dicumyl peroxide,
Organic compounds such as 1,1-di-t-butyl-peroxy-3,3,5-trimethylcyclohexane, t-butylperoxy-2-ethylhexanoate, bis (4-t-butylcyclohexyl) peroxydicarbonate Peroxides and the like can also be used. The amount of the organic peroxide used in this reaction is within the range of 1 to 10 parts by weight based on 100 parts by weight of the total amount of the curable compound (3).

Such a catalyst can be added when the solvent-soluble polyimide resin and the curable compound are blended to prepare a coating agent composition. At this time, a hydrosilylation reaction may partially occur and a crosslinked structure may partially occur, but it must be soluble in a solvent. The heat-resistant coating agent composition of the present invention contains a solvent-soluble polyimide resin and a curable compound or a compound in which these partially form a cross-linked structure and is solvent-soluble, which is usually dissolved in an organic solvent. It is used as it is. It can also be used in the form of a film.
The hydrosilylation reaction is usually performed within the range of 50 to 200 ° C. This reaction can occur during the drying process during the coating process when used as a coating agent. The coating film obtained by sufficiently developing the crosslinked structure is insoluble in the solvent and has excellent heat resistance. The heat-resistant coating agent composition of the present invention comprising each of the above compounds can be used in the form of varnish or film. As specific examples of the coating agent according to the present invention, a wide range of applications such as coating agents for electronic materials, heat resistant paints, and heat resistant adhesive materials can be expected.

[0020]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The abbreviations used in this example indicate the following compounds. BTDA: 3,3 ', 4,4'-benzophenone tetracarboxylic acid dianhydride DSDA: 3,3', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride BAPP: 2,2-bis [4- ( 4-aminophenoxy) phenyl] propane BAPS-M: bis- [4- (3-aminophenoxy) phenyl] sulfone NMP: N-methyl-2-pyrrolidone Dig: diethylene glycol dimethyl ether PSX1: said compound (A) having an average molecular weight of 800 Diaminopolysiloxane PSX2: diaminopolysiloxane of the compound (A) having an average molecular weight of 1000 PSX3: diaminopolysiloxane having an average molecular weight of 800 and having no vinyl group

Example 1 BTDA (61.2 g, 0.18) was placed in a Deen-Shurark type 1 liter separable flask.
7 mol) and NMP (175 g) were charged and mixed well under a room temperature atmosphere. Next, vinyl group-containing diaminopolysiloxane PSX1 (15 g, 0.019
A solution obtained by dissolving (mol) in Dig (150 g) was added to the reaction system using a dropping funnel. Then, change the solution temperature to 3
Keeping the temperature below 0 ℃, BAPS-M (73.8g, 0.169m
was added to adjust the solid content to be 30% by weight. Thereafter, stirring was continued at room temperature for 2 hours to synthesize a polyamic acid. Furthermore, in order to carry out the heating imidization reaction, the temperature is gradually raised at a temperature rising rate of 5 ° C./minute, and
Was continuously distilled out of the reaction system without returning it to the reaction system and reacted at 190 ° C. for 6 hours to complete the imidization reaction. The logarithmic viscosity of this resin at a concentration of 0.5% by weight in an NMP solution was 0.55 dl / g.

Further, the polyimide resin solution synthesized by the above method was cooled to room temperature, and 20 parts by weight of a siloxane compound (PSX5) as a curable compound was added to 100 parts by weight of the solid content of the polyimide resin in the resin solution. Then chloroplatinic acid (H ₂ PtCl ₆・ 6H ₂ O) was used as a hydrosilylation catalyst.
Add 0.001 parts by weight and stir for 1 hour. After stirring,
A part of the obtained solution was applied on a glass substrate and dried at 80 ° C. for 1 hour, 150 ° C. for 30 minutes and 200 ° C. for 30 minutes to form a coating film, and a coating film performance test was conducted. . Table 1 shows the raw material composition of the synthesized polyimide resin solution, the solution characteristics, and the performance result of the coating film.

Examples 2 to 9 By the same method as in Example 1, the reaction was carried out with the composition shown in Table 1 to synthesize a polyimide resin solution. Furthermore, Example 1
After forming a coating film by the same method as the above, the performance test of the coating film was conducted. Table 1 shows the results.

Comparative Examples 1 and 2 Diaminopolysiloxane (PS containing no vinyl group)
A polyimide resin composition solution was synthesized in the same manner as in Example 1 except that X3) was used. Furthermore, after forming a coating film by the same method as in Example 1, a performance test of the coating film was conducted. Table 1 shows the results.

Comparative Examples 3 to 4 A coating film was formed in the same manner as in Example 1 without blending the curable compound, and then the coating film was tested for performance. Table 1 shows the results.

[0026]

[Table 1]

[0027]

The coating composition of the present invention is excellent in heat resistance, chemical resistance, adhesiveness and electrical characteristics.
Therefore, the heat-resistant coating composition of the present invention is extremely useful as a coating agent for semiconductors and printed circuits, heat-resistant paints, heat-resistant adhesive materials and the like.

Claims (3)

[Claims] 1. (a) The following general formula (1): 1 to 80 mol% of the repeating unit represented by the following general formula (2) With respect to 100 parts by weight of an organic solvent-soluble polyimide resin consisting of 99 to 20 mol% of the repeating unit represented by
The following general formula (3): A heat-resistant coating agent composition comprising 1 to 200 parts by weight of a curable compound represented by 2. The heat-resistant coating agent composition according to claim 1, wherein the polyimide resin and the curable compound partially form a crosslinked structure by a hydrosilylation reaction. 3. A coating film obtained by curing the heat-resistant coating agent composition according to claim 1 or 2.