JP2007106836A - Silane-modified polyamic acid resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent polyimide-silica hybrid cured product or multilayered product with excellent adhesivity and insulating property. <P>SOLUTION: This silane-modified polyamic acid resin composition comprises an alkoxy group-containing silane-modified polyamic acid obtained by reacting a polyamic acid(1) having a diamine residue with a benzoxazole skeleton and an epoxy group-containing alkoxysilane partial condensate(2) obtained by dealcoholization reaction of an epoxy compound(A) having one hydroxy group in a molecule with an alkoxysilane partial condensate(B), and a polar solvent. The silane-modified polyamic acid resin composition is made into a surface coating agent by coating, etc., to be multilayered on a film or substrate each with a specific coefficient of linear expansion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an alkoxy group-containing silane-modified polyamide acid composition of a specific polyamide acid, a silane-modified polyamide acid resin composition containing a solvent, a semi-cured product thereof, and a polyimide-silica hybrid cured product. In particular, a silane-modified polyamic acid resin composition containing an alkoxy group-containing silane-modified polyamic acid, a resin composition for electric insulation and an electric insulating material using a technique such as coating, impregnation, film molding, The present invention relates to a silane-modified polyamic acid resin composition that can be used as a heat-resistant coating agent.

The alkoxy group-containing silane-modified polyamic acid resin composition of the present invention and the polyimide-silica hybrid cured product obtained by coating, impregnating, film forming and the like of the resin composition are a copper-clad board for a printed board and a build-up printed board. It is useful for electrical insulation as a liquid crystal component such as a liquid crystal alignment film and a wire coating agent in addition to an electronic material such as a resist interlayer such as an interlayer insulating material, a semiconductor interlayer insulating film, a solder resist, a conductive paste, and a TAB tape. The alkoxy group-containing silane-modified polyamic acid resin composition of the present invention is also useful as a heat-resistant adhesive such as an adhesive for printed circuit boards, a metal paint, or a heat-resistant coating agent.
In particular, polyimide films having a benzoxazole ring in the main chain (polyimide benzoxazole film) have excellent mechanical properties in tensile tensile strength and tensile modulus, suitable linear expansion coefficient, and improved surface properties such as adhesion. The present invention relates to the composition used for the film.

Polyimide films have very little change in physical properties over a wide temperature range from −269 to 300 ° C., and therefore, applications and uses in the electric and electronic fields are expanding. In the electric field, for example, it is used for coil insulation of vehicle motors, industrial motors, etc., insulation of aircraft electric wires and superconducting wires. On the other hand, in the electronic field, for example, it is used for a flexible printed circuit board, a base film of a film carrier for semiconductor mounting, and the like. Thus, the polyimide film is widely used in the electric and electronic fields as a highly reliable film among various functional polymer films. Recently, however, major problems have become apparent with the refinement of the electric and electronic fields. For example, a printed circuit board made of a polyimide film base material in which copper is copper-clad by vapor deposition or plating or the like has a tendency that the adhesive force of the copper layer is lowered due to a change with time and an environmental change, and further peeling occurs.
In addition, ceramic has been conventionally used as a material for base materials of electronic components such as information communication equipment (broadcast equipment, mobile radio equipment, portable communication equipment, etc.), radar, high-speed information processing devices, and the like. A base material made of ceramic has heat resistance, and can cope with an increase in the frequency band (reaching the GHz band) of information communication equipment in recent years. However, ceramics are not flexible and cannot be thinned, so the fields that can be used are limited.

For this reason, studies have been made to use a film made of an organic material as a base material for an electronic component, and a film made of polyimide and a film made of polytetrafluoroethylene have been proposed. A film made of polyimide has excellent heat resistance and has the advantage that the film can be thin because it is tough. However, there are concerns about problems such as low signal strength and signal transmission delay when applied to high-frequency signals. However, the tensile strength at break and the tensile modulus are still insufficient, and the linear expansion coefficient is too large. A film made of polytetrafluoroethylene can handle high frequencies, but the tensile modulus is low, so the film cannot be made thin, the adhesion to metal conductors and resistors on the surface is poor, and the coefficient of linear expansion However, it is problematic in that it is not suitable for the production of a circuit having fine wiring due to a large dimensional change due to temperature change. Thus, a film having sufficient physical properties for a substrate having heat resistance, high mechanical properties, and flexibility has not been obtained yet.
As a polyimide film having a high elastic modulus, a polyimide benzoxazole film made of polyimide having a benzoxazole ring in the main chain has been proposed (see Patent Document 1). A printed wiring board using this polyimide benzoxazole film as a dielectric layer has also been proposed (see Patent Documents 2 and 3).

Polyimide benzoxazole films consisting of polyimides with these benzoxazole rings in the main chain have improved tensile tensile strength and tensile elastic modulus and are within the range of satisfactory linear expansion coefficients. In spite of its physical properties, it has problems such as insufficient surface properties in terms of adhesion.
Various proposals have been made to improve the adhesion of polyimide with excellent physical properties. For example, a polyimide film that has a thermoplastic resin layer on at least one surface of a polyimide film that does not have adhesion (see Patent Document 4), a polyimide film And at least a two-layer film in which a film made of polyamide resin is laminated (see Patent Document 5).
Even though those with a thermoplastic resin layer on these polyimide films can be satisfied in improving the adhesiveness, the low heat resistance of these thermoplastic resins will ruin the heat resistance of the folded polyimide film. Had a trend.
Japanese Patent Laid-Open No. 06-56992 Japanese National Patent Publication No. 11-504369 Japanese National Patent Publication No. 11-505184 Japanese Patent Laid-Open No. 09-169088 JP 07-186350 A

The polyimide resin is generally obtained by ring-closing reaction of polyamic acid synthesized by using aromatic tetracarboxylic acid anhydride and aromatic diamine as raw materials and condensing them. Such a polyimide resin is excellent in heat resistance and electrical properties and has flexibility, so as a heat resistant material or an insulating material, various forms such as a film, a coating agent, an electronic material, a liquid crystal, an adhesive, Widely used in fields such as paint.
However, with recent developments in various fields such as the electronic materials field, higher levels of mechanical strength, low thermal expansion, insulation, and high adhesion are required for polyimides used in the field. ing.
For the purpose of imparting more excellent mechanical strength and low thermal expansibility to the polyimide polymer, fillers and the like are generally added as appropriate, but mechanical strength such as elastic modulus is slightly improved in these compositions. However, it is not sufficient, and the film obtained on the contrary tends to be brittle and tend to have reduced flexibility and adhesion.
A silica hybrid material obtained by mixing an alkoxysilane with a polyamic acid solution has been proposed (see Patent Documents 6 to 8). However, in the coatings obtained from these materials, silica is not sufficiently dispersed in the coating, so that the coating is whitened or warped, and mechanical strength such as elastic modulus and heat resistance are improved. Is insufficient.
JP-A-63-099234, JP 63-099235 A, JP 63-099236 A

  An object of the present invention is to provide an alkoxy group-containing silane-modified polyamic acid resin composition capable of obtaining a cured product having excellent mechanical strength and heat resistance. Further, by using this alkoxy group-containing silane-modified polyamic acid, it is possible to obtain a transparent polyimide-silica hybrid cured product that is excellent in heat resistance, mechanical strength, and insulation, and that does not warp or crack. In addition to the above, the present invention retains a polyimide benzoxazole film made of polyimide having a benzoxazole ring in the main chain within a range that is satisfactory in terms of tensile breaking strength, excellent physical properties in tensile modulus, and linear expansion coefficient. An object of the present invention is to provide a silane-modified polyamic acid resin composition whose surface characteristics are improved in adhesiveness and insulation so as not to impair the excellent mechanical properties.

The present invention relates to an alkoxy group-containing silane obtained by reacting a polyamic acid obtained by reacting an aromatic diamine having a benzoxazole structure with an aromatic tetracarboxylic acid anhydride and an epoxy group-containing alkoxysilane partial condensate. The present inventors have found that a modified polyamic acid can solve the above-mentioned problems and have achieved the object.
That is, this invention consists of the following structures.
1. Epoxy group obtained by dealcoholization reaction of polyamic acid (1) having diamine residue having benzoxazole skeleton, epoxy compound (A) having one hydroxyl group in one molecule and alkoxysilane partial condensate (B) A silane-modified polyamic acid resin composition comprising an alkoxy group-containing silane-modified polyamic acid obtained by reacting the containing alkoxysilane partial condensate (2) and a polar solvent.
2. 2. The silane-modified polyamic acid resin composition according to 1, wherein the linear thermal expansion coefficient (CTE) is applied to the surface of an organic substrate or an inorganic substrate having a value of 0 ppm / ° C. or more and 20 ppm / ° C. or less.
3. 2. The silane-modified polyamic acid resin composition as described in 1 above, which is used by being applied to the surface of a silicon wafer.
4). 2. The silane-modified polyamic acid resin composition according to 1 above, which is used by being applied to the surface of a polyimide film having a diamine residue having a benzoxazole skeleton.

  Obtained by dealcoholization reaction of the polyamic acid (1) having a diamine residue having a benzoxazole skeleton of the present invention, an epoxy compound (A) having one hydroxyl group in one molecule, and an alkoxysilane partial condensate (B). The alkoxy group-containing silane-modified polyamic acid obtained by reacting the resulting epoxy group-containing alkoxysilane partial condensate (2), and the silane-modified polyamic acid resin composition containing a polar solvent have heat resistance, mechanical strength, and insulating properties. And a transparent cured polyimide-silica hybrid can be provided. A laminate obtained by laminating a silane-modified polyimide layer obtained by drying and curing this resin composition and a substrate having a low linear expansion coefficient in a specific range has excellent bonding properties, warping, cracking, peeling, etc. Does not occur.

The silane-modified polyamic acid resin composition of the present invention comprises a polyamic acid (1) having a diamine residue having a benzoxazole skeleton, an epoxy compound (A) having one hydroxyl group in one molecule, and an alkoxysilane partial condensate ( A silane-modified polyamic acid comprising an alkoxy group-containing silane-modified polyamic acid obtained by reacting with an epoxy group-containing alkoxysilane partial condensate (2) obtained by a dealcoholization reaction with B), and a polar solvent It is a resin composition.
The polyamic acid (1) having a diamine residue having a benzoxazole skeleton in the present invention includes, for example, an aromatic tetracarboxylic acid such as pyromellitic acid (including an anhydride and a derivative) and an aromatic diamine having a benzoxazole skeleton; Is a polyamic acid which is a polyimide precursor obtained by reacting in a solvent.

Specific examples of the aromatic diamine having a benzoxazole structure used in the present invention include the following.

Among these, amino (aminophenyl) benzoxazole isomers are more preferable from the viewpoint of ease of synthesis when preparing an alkoxy group-containing silane-modified polyamic acid and physical properties of the resulting polyimide. Here, “each isomer” refers to each isomer in which two amino groups of amino (aminophenyl) benzoxazole are determined according to the coordination position (eg, the above “formula 1” to “formula 4”). Each compound described in the above. These diamines may be used alone or in combination of two or more.
In the present invention, the aromatic diamine having the benzoxazole structure is used in an amount of 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more.

In the present invention, the following aromatic diamine may be used, but preferably less than 30 mol% of the total diamine, and one or more diamines having no benzoxazole structure exemplified below, You may use together.
Examples of such diamines include 4,4′-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, and bis [4- (3-aminophenoxy) phenyl]. Sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine,

3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide 4,4'-diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'- Diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane, 1 , 1-Bi [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] propane, 1 , 2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl ]propane,

1,1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4- (4-aminophenoxy) phenyl] butane, 1,4-bis [4- (4-aminophenoxy) Phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,3-bis [4- (4-aminophenoxy) phenyl] butane, 2- [4- (4-aminophenoxy) Phenyl] -2- [4- (4-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) -3-methylphenyl] propane, 2- [4- ( 4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) -3,5-dimethylphen Le] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane,

1,4-bis (3-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) ) Biphenyl, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [4- ( 4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,3-bis [4- (4-aminophenoxy) ) Benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3 Aminophenoxy) benzoyl] benzene, 4,4′-bis [(3-aminophenoxy) benzoyl] benzene, 1,1-bis [4- (3-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-Aminophenoxy) phenyl] propane, 3,4'-diaminodiphenyl sulfide.

  2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] methane, 1,1 -Bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, bis [4- (3-aminophenoxy) phenyl] sulfoxide, 4,4 '-Bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [4- (4-amino-α) , Α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis 4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3 -Bis [4- (4-amino-6-fluorophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl Benzene, 1,3-bis [4- (4-amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene,

3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-diphenoxybenzophenone, 3,4′-diamino-4,5′-diphenoxybenzophenone, 3, 3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3 '-Diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'-diamino-4,5'-dibiphenoxybenzophenone, 3,3'- Diamino-4-biphenoxybenzophenone, 4,4′-diamino-5-biphenoxybenzophenone, 3,4 -Diamino-4-biphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis (3-amino-4-phenoxybenzoyl) benzene, 1,4-bis (3-amino- 4-phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-phenoxybenzoyl) benzene, 1,4-bis (4-amino-5-phenoxybenzoyl) benzene, 1,3-bis (3-amino) -4-biphenoxybenzoyl) benzene, 1,4-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,3-bis (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-Amino-5-biphenoxybenzoyl) benzene, 2,6-bis [4- (4-amino-α, α-dimethylbenzyl) pheno Si] benzonitrile and some or all of the hydrogen atoms on the aromatic ring in the aromatic diamine are halogen atoms, alkyl groups having 1 to 3 carbon atoms or alkoxyl groups, cyano groups, or alkyl groups or alkoxyl group hydrogen atoms. Examples thereof include aromatic diamines substituted with a halogenated alkyl group having 1 to 3 carbon atoms, partially or entirely substituted with halogen atoms, or alkoxyl groups.

As the tetracarboxylic acid anhydride used in the present invention, pyromellitic acid anhydride (shown in Chemical formula 14) is preferably used among aromatic tetracarboxylic acid anhydrides, but is not limited thereto.
Pyromellitic acid is used in an amount of 70 mol% or more, preferably 80 mol%, more preferably 90 mol% or more based on the total tetracarboxylic acid, and can be used in addition to pyromellitic acid. Specific examples include those having a chemical formula of 15 or less.

これらのテトラカルボン酸二無水物は単独で用いてもよいし、二種以上を併用してもよい。

These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  Epoxy group-containing alkoxysilane partial condensate obtained by dealcoholization reaction of polyamic acid (1) in the present invention, epoxy compound (A) having one hydroxyl group in one molecule and alkoxysilane partial condensate (B) ( 2) In the silane-modified polyamic acid resin composition containing an alkoxy group-containing silane-modified polyamic acid obtained by reacting with 2) and a polar solvent, the polyamic acid (1) is tetracarboxylic acid as described above. (Including anhydrides and derivatives) and aromatic diamines having a benzoxazole structure (including derivatives thereof) in a solvent can be obtained as a polyamic acid solution that is a polyimide precursor. As the acid (including anhydrides and derivatives) and diamine, those exemplified above can be used. In addition, trimellitic anhydride, tricarboxylic acids such as butane-1,2,4-tricarboxylic acid, naphthalene-1,2,4-tricarboxylic acid, oxalic acid, malonic acid, Aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, vimelic acid, suberic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid and their acid anhydrides, isophthalic acid, terephthalic acid, diphenylmethane-4 Aromatic dicarboxylic acids such as 4,4'-dicarboxylic acid and acid anhydrides thereof can be used in combination. However, if these ratios with respect to tetracarboxylic acids are too large, the resulting cured product tends to have poor insulation and heat resistance, so the amount used is usually 30 mol% or less based on tetracarboxylic acids. Is preferred.

For example, a polyamic acid solution obtained by reacting tetracarboxylic acids and diamines in a polar solvent, usually at −20 ° C. to 60 ° C. can be used. The molecular weight of the polyamic acid (1) is not particularly limited, but preferably has a number average molecular weight of about 3000 to 50000.
The polyamic acid (1) is obtained by reacting the above tetracarboxylic acids and diamines in a polar solvent in the range of (number of moles of tetracarboxylic acids / number of moles of diamines) = 0.9 to 1.1. The polar solvent is not particularly limited as long as it dissolves the polyamic acid (1) to be produced, but it is aprotic such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, and cresol. The polar solvent is preferably produced with a polyimide-converted solid residue of 5 to 40%.
The epoxy group-containing alkoxysilane partial condensate (2) used in the present invention is composed of an epoxy compound (A) having one hydroxyl group in one molecule (hereinafter also simply referred to as an epoxy compound (A)) and an alkoxysilane partial condensation. It is obtained by dealcoholization reaction with the product (B).
As the epoxy compound (A), the number of epoxy groups is not particularly limited as long as it is an epoxy compound having one hydroxyl group in one molecule. In addition, as the epoxy compound (A), the smaller the molecular weight, the better the compatibility with the alkoxysilane partial condensate (3), and the higher the heat resistance and adhesion imparting effect. Is preferred. Among these epoxy compounds, glycidol is most excellent in terms of heat resistance imparting effect, and is most suitable because of its high reactivity with the alkoxysilane partial condensate (B).

As the alkoxysilane partial condensate (B),
Formula (1): R ¹ _m Si (OR ² ) _(4-m)
(In the formula, m represents an integer of 0 or 1, R ¹ represents an alkyl group or aryl group having 8 or less carbon atoms, and R ² represents a lower alkyl group having 4 or less carbon atoms.)
A hydrolyzable alkoxysilane monomer represented by the formula (1) is hydrolyzed in the presence of an acid or base catalyst and water and partially condensed.
Specific examples of the hydrolyzable alkoxysilane monomer that is a raw material of the alkoxysilane partial condensate (B) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane, methyltrimethoxysilane, and ethyltrimethoxy. Examples include trialkoxysilanes such as silane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, and isopropyltriethoxysilane. Usually, among these, since the reactivity with glycidol is particularly high, the alkoxysilane partial condensate (B) is preferably synthesized using tetramethoxysilane or methyltrimethoxysilane in an amount of 70 mol% or more.
The number average molecular weight of the alkoxysilane partial condensate (B) is preferably about 230 to 2000, and the average number of Si in one molecule is preferably about 2 to 11.

The epoxy group-containing alkoxysilane partial condensate (2) is obtained by subjecting the epoxy compound (A) and the alkoxysilane partial condensate (B) to a dealcoholization reaction. The proportion of the epoxy compound (A) and the alkoxysilane partial condensate (B) used is not particularly limited as long as the alkoxy group substantially remains, but the resulting epoxy group-containing alkoxysilane partial condensate ( 2) The amount of the epoxy group in the mixture is usually such that the equivalent of the hydroxyl group of the epoxy compound (A) / the equivalent of the alkoxyl group of the alkoxysilane condensate (B) = 0.01 / 1 to 0.5 / 1. It is preferable to subject the alkoxysilane condensate (B) and the epoxy compound (A) to a dealcoholization reaction at a ratio. In the reaction of the alkoxysilane partial condensate (B) and the epoxy compound (A), for example, a dealcoholization reaction is performed while the above components are charged and alcohol produced by heating is distilled off. The reaction temperature is about 50 to 150 ° C., preferably 70 to 110 ° C., and the total reaction time is about 1 to 15 hours.
In the dealcoholization reaction of the alkoxysilane partial condensate (B) and the epoxy compound (A), use of a conventionally known ester-hydroxyl transesterification catalyst that does not open the epoxy ring in order to accelerate the reaction. Can do. For example, metals such as lithium, sodium, potassium, magnesium, calcium, zinc, aluminum, titanium, cobalt, germanium, tin, boron, cadmium, manganese, oxides, organic acid salts, halides, alkoxides, etc. It is done. Among these, organic tin and organic acid tin are particularly preferable, and specifically, dibutyltin dilaurate and tin octylate are effective. The reaction can also be carried out in a solvent. The solvent is not particularly limited as long as it dissolves the alkoxysilane condensate and glycidol and is inert to the epoxy group of the epoxy compound (A). As such an organic solvent, for example, a solvent such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, xylene is preferably used.

The alkoxy group-containing silane-modified polyamic acid is obtained by reacting the polyamic acid (1) with the epoxy group-containing alkoxysilane partial condensate (2). The use ratio of the polyamic acid (1) and the epoxy group-containing alkoxysilane partial condensate (2) is not particularly limited, but (equivalent of the epoxy group of the epoxy group-containing alkoxysilane partial condensate (2)) / (polyamic acid ( The equivalent of the carboxylic acid group of the tetracarboxylic acids used in 1) is preferably in the range of 0.01 to 0.4.
In the above reaction, a catalyst used for reacting a conventionally known epoxy group with a carboxylic acid for promoting the reaction can be used. Tertiary amines such as 1,8-diaza-bicyclo [5,4,0] -7-undecene, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; Imidazoles such as methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole and benzimidazole; organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine Class: Tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, N-methylmorpholine tetraphenylborate And the like tetraphenyl boron salts and the like. The reaction catalyst is preferably used at a ratio of 0.01 to 5 parts by mass with respect to 100 parts by mass of the polyimide-residue solid residue of the polyamic acid.

The reaction is preferably performed in a solvent. The solvent is not particularly limited as long as it dissolves the polyamic acid (1) and the epoxy group-containing alkoxysilane partial condensate (2). Examples of such solvents include those using aprotic polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, and cresol at the time of polyamic acid production.
The alkoxy group-containing silane-modified polyamic acid resin composition obtained as described above has an alkoxy group derived from the alkoxysilane partial condensate (B) in the molecule. The content of the alkoxy group is not particularly limited, but the alkoxy group is bonded to each other by evaporation of a solvent, heat treatment, or sol-gel reaction or dealcoholization condensation by reaction with moisture (humidity). Since it is necessary to form a cured product, the alkoxy group-containing silane-modified polyamic acid is usually 50 to 95 mol%, preferably 60 to 90 mol% of the alkoxy group of the alkoxysilane partial condensate (B). It is better to keep it as it is.
When the alkoxy group-containing silane-modified polyamic acid resin composition is used, other components are not particularly limited as long as the alkoxy group-containing silane-modified polyamic acid resin is contained, and the filler, release agent, surface Treatment agents, flame retardants, viscosity modifiers, plasticizers, antibacterial agents, antifungal agents, leveling agents, antifoaming agents, colorants, stabilizers, coupling agents and the like may be blended.
In the present invention, a silane-modified polyimide is obtained from the silane-modified polyamic acid resin composition. That is, from the silane-modified polyamic acid resin composition, the composition is subjected to processing such as coating on the substrate, and then cured at about 150 to 500 ° C. to obtain a silane-modified polyimide. In order to exhibit the characteristics and effects of the resulting silane-modified polyimide (also referred to as cured product), the resin composition of the present invention is applied to the surface of a substrate having a low linear expansion coefficient in a specific range and dried and cured. It is preferable to laminate.

Examples of the substrate having a low linear expansion coefficient in a specific range in the present invention include an organic substrate or an inorganic substrate having a linear thermal expansion coefficient (CTE) of 0 ppm / ° C. or more and 20 ppm / ° C. or less, such as a silicon wafer or benzo Examples include polyimide films having a diamine residue having an oxazole skeleton (hereinafter also referred to as layer (b)), and the silane-modified polyamic acid resin composition of the present invention is applied to these surfaces to warp, crack, peel off, etc. A laminated body with less can be obtained.
The effect of the silane-modified polyamic acid resin composition of the present invention is more effectively exhibited when the organic base material or inorganic base material has a linear thermal expansion coefficient (CTE) of 0 ppm / ° C. or more and 10 ppm / ° C. or less, and warpage. In addition, it is possible to obtain a laminate in which cracking, peeling, and the like are further reduced.
The method for laminating is not particularly limited as long as there is no problem in adhesion between both layers, and any method may be used as long as it adheres without using another layer such as an adhesive layer. , A method by coextrusion, a method in which the silane-modified polyamic acid resin composition of the present invention is cast on the surface of a silicon wafer or a polyimide film, dried and cured to obtain a silane-modified polyimide, a silane-modified on the surface of a silicon wafer or a polyimide film Examples thereof include a method in which the polyamic acid resin composition is applied by spray coating or the like, dried and cured to obtain a silane-modified polyimide.

The multilayer body of the present invention may have at least the (a) layer and the (b) layer laminated, but the (a) layer is laminated on the (b) layer, (a) / (b ) / (A) is preferred in which the (a) layer is laminated on both sides of the (b) layer.
The thickness ratio of (a) / (b) in the multilayer body of the present invention is not particularly limited, but for the purpose of the present invention, the thickness ratio of (a) / (b) (in the case of a three-layer structure) (A) is a calculation in a single layer) is 0.001 to 0.5, more preferably 0.3 or less. If the thickness ratio of (a) / (b) exceeds 0.5, the mechanical strength may be insufficient or the linear expansion coefficient may be too large. On the other hand, if it is less than 0.001, the effect of improving the surface characteristics may be insufficient.

The thickness of the multilayer body of the present invention is not particularly limited, but when used as a substrate of a flexible printed circuit board, it is preferable that the thickness of the layer (b) mainly responsible for mechanical strength is 3 to 50 μm. .
In addition, a polyimide film having a diamine residue having a benzoxazole skeleton as at least an aromatic diamine residue, which is an example of the layer (b) in the present invention, has excellent tensile breaking strength and tensile elastic modulus. The linear expansion coefficient also has a relatively low value, but more preferably has at least a pyromellitic acid residue as a residue of an aromatic tetracarboxylic acid and a benzoxazole skeleton as a residue of an aromatic diamine. A polyimide film having a diamine residue is a film having a tensile breaking strength of 300 MPa or more, a tensile modulus of 5 GPa or more, and a linear expansion coefficient of 1 to 5 ppm / ° C.

Measurements of tensile strength at break, tensile modulus, and linear expansion coefficient are as follows.
<Measurement of tensile strength and tensile modulus of polyimide film>
A test piece was prepared by cutting a polyimide film to be measured into a strip of 100 mm × 10 mm in the MD direction and the TD direction, respectively. Using a tensile tester (manufactured by Shimadzu Corp., Autograph (registered trademark) model name AG-5000A) under the conditions of a tensile speed of 50 mm / min and a distance between chucks of 40 mm, the tensile modulus and tension in each of the MD and TD directions. The breaking strength and tensile breaking elongation were measured.
<Measurement of linear expansion coefficient>
For polyimide films to be measured, etc., the stretch rate / temperature at intervals of 30 ° C. to 40 ° C., 40 ° C. to 50 ° C.,... And 10 ° C. is measured. The average value of all measured values was calculated as CTE (average value).
Device name: TMA4000S manufactured by MAC Science
Sample length; 10mm
Sample width: 2 mm
Temperature rise start temperature: 25 ° C
Temperature rising end temperature: 400 ° C
Temperature increase rate: 5 ° C / min
Atmosphere: Argon

In the multilayer polyimide film of the present invention, the layer (a) and the layer (b) are provided with a lubricant in the polyimide to give fine irregularities on the surface of the layer (film), thereby improving the slipperiness of the film. It is preferable.
As the lubricant, inorganic or organic fine particles having an average particle diameter of about 0.03 μm to 3 μm can be used. Specific examples include titanium oxide, alumina, silica, calcium carbonate, calcium phosphate, calcium hydrogen phosphate, calcium pyrophosphate, Examples include magnesium oxide, calcium oxide, and clay minerals.
In the present invention, the surface of the obtained multilayer polyimide film (particularly the surface of (a)) is preferably subjected to corona treatment, atmospheric pressure plasma treatment and vacuum plasma discharge treatment in order to further increase the adhesive force. is there.
The atmospheric pressure plasma treatment is preferably an inert gas plasma, and nitrogen gas, Ne, Ar, Kr, or Xe is used as the inert gas. There is no particular limitation on the method for generating plasma, and an inert gas may be introduced into the plasma generator to generate plasma. The time required for the plasma treatment is not particularly limited, and is usually 1 second to 30 minutes, preferably 10 seconds to 10 minutes. There are no particular restrictions on the frequency and output of the plasma during the plasma processing, the gas pressure for generating the plasma, and the processing temperature as long as they can be handled by the plasma processing apparatus. The frequency is usually 13.56 MHz, the output is usually 50 W to 1000 W, the gas pressure is usually 0.01 Pa to 10 Pa, and the temperature is usually 20 ° C. to 250 ° C., preferably 20 ° C. to 180 ° C. If the output is too high, the film surface may crack. If the gas pressure is too high, the smoothness of the film surface may be reduced.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited by these Examples. In addition, evaluation and measurement in Examples and the like are as follows except for those described above. In addition, it is appropriately described in the description of examples and the like.
1. Reduced viscosity of polyamic acid (ηsp / C)
A solution dissolved in N-methyl-2-pyrrolidone so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. using an Ubbelohde type viscosity tube.
2. Film thickness The film thickness was measured using a micrometer (Finereuf, Millitron (registered trademark) 1254D).
3. Peel strength (peel strength of multilayer film)
The peel strength was defined as the strength required when the multilayer film to be measured was peeled off in the 90-degree direction. The measurement was performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph (registered trademark) model name AG-5000A) according to JIS C6418.
(Peeling strength of metallized film)
After the metallized film to be measured was processed into a TAB tape pattern with a wiring width of 90 μm, the peel strength was defined as the strength required when peeled off in the 90 ° direction. The measurement was performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph (registered trademark) model name AG-5000A) according to JIS C6418.
4). Adhesiveness of the coating film The adhesiveness of the coating film to be measured was evaluated based on the residual film ratio by a cross-cut test. The cross cut test was carried out according to the test method of JIS K5600 on a cross cut of a total of 100 squares (1 square; 1 mm width).

[Polymerization of polyamic acid (a)]
<Polymerization of a polyamic acid composed of a diamine having a benzoxazole structure>
The inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 500 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole was charged. Next, 9000 parts by mass of N-methyl-2-pyrrolidone was added and completely dissolved, and then 485 parts by mass of pyromellitic dianhydride was added and stirred at a reaction temperature of 25 ° C. for 48 hours. A polyamic acid solution (I) was obtained. Ηsp / C of the obtained solution was 4.2 dl / g.

[Polymerization of silane-modified polyamic acid (b)]
In a reactor equipped with a stirrer, a water separator, a thermometer, and a nitrogen gas introduction pipe, 1400 parts by mass of glycidol (manufactured by NOF Corporation, trade name “Epiol OH”) and a tetramethoxysilane partial condensate (Tama Chemical ( Co., Ltd., trade name “Methyl silicate 51”, Si having an average number of 4) of 4478.9 parts by mass, and 1.1 parts by mass of dibutyltin dilaurate was added and reacted under a nitrogen stream. During the reaction, methanol produced using a water separator was distilled off, and the reaction was cooled when the amount reached about 580 parts by mass. The time required for cooling after raising the temperature was 6 hours. Subsequently, about 30 parts by mass of methanol remaining in the system was removed under reduced pressure at 13 kPa for about 10 minutes. In this way, an epoxy group-containing alkoxysilane partial condensate was obtained.
In addition, the equivalent of the hydroxyl group of the epoxy compound at the time of preparation / the alkoxy group of the alkoxysilane partial condensate (equivalent ratio) = 0.20, and the epoxy equivalent is 279 g / eq.
The inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 500 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole was charged. Next, 9000 parts by mass of N-methyl-2-pyrrolidone was added and completely dissolved, and then 485 parts by mass of pyromellitic dianhydride was added and stirred at a reaction temperature of 25 ° C. for 48 hours. A polyamic acid solution was obtained. Ηsp / C of the obtained solution was 4.2 dl / g.
Next, the temperature was raised to 80 ° C., 324 parts by mass of the epoxy group-containing alkoxysilane partial condensate was added, and the mixture was stirred at 80 ° C. for 9 hours to obtain a silane-modified polyamic acid (B). (Equivalent epoxy group of epoxy group-containing alkoxysilane partial condensate / number of moles of tetracarboxylic dianhydride (A) used for polyamic acid) = 0.52.

[Polymerization of silane-modified polyamic acid (c)]
In a reactor equipped with a stirrer, a water separator, a thermometer, and a nitrogen gas introduction pipe, 1400 parts by mass of glycidol (manufactured by NOF Corporation, trade name “Epiol OH”) and a tetramethoxysilane partial condensate (Tama Chemical ( Co., Ltd., trade name “Methyl silicate 51”, Si having an average number of 4) of 4478.9 parts by mass, and 1.1 parts by mass of dibutyltin dilaurate was added and reacted under a nitrogen stream. During the reaction, methanol produced using a water separator was distilled off, and the reaction was cooled when the amount reached about 580 parts by mass. The time required for cooling after raising the temperature was 6 hours. Subsequently, about 30 parts by mass of methanol remaining in the system was removed under reduced pressure at 13 kPa for about 10 minutes. In this way, an epoxy group-containing alkoxysilane partial condensate was obtained.
In addition, the hydroxyl group equivalent of the epoxy compound at the time of preparation / the alkoxy group (equivalent ratio) of the alkoxysilane partial condensate = 0.20, and the epoxy equivalent was 279 g / eq.
Separately, the inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 545 parts by mass of pyromellitic acid anhydride, 500 parts by mass of 4,4′diaminodiphenyl ether and 9000 parts by mass of dimethylacetamide were added. Prepared. After stirring for 48 hours at a reaction temperature of 20 ° C., a pale yellow and viscous polyamic acid solution was obtained. The solution obtained had a ηsp / C of 2.5 dl / g.
Next, the temperature was raised to 80 ° C., 324 parts by mass of the epoxy group-containing alkoxysilane partial condensate was added, and the mixture was stirred at 80 ° C. for 9 hours to obtain a silane-modified polyamide acid (C). (Equivalent epoxy group of epoxy group-containing alkoxysilane partial condensate / number of moles of tetracarboxylic dianhydride (A) used for polyamic acid) = 0.54.

Example 1
(B) The above-mentioned polyamic acid solution (a) as a layer and silane-modified polyamic acid (b) as a layer (a) were coextruded and coated on a stainless steel belt using a T-type die. The lip gap of the die was (a) layer 150 μm and (b) layer 500 μm. Next, the polyamic acid film having self-supporting property obtained by drying at 90 ° C. for 60 minutes was peeled off from the stainless steel belt to obtain a polyimide precursor film (also referred to as a green film) having a thickness of 40 μm.
The obtained green film was heated in a continuous drying oven at 170 ° C. for 3 minutes, then heated to 450 ° C. in about 20 seconds and heated at 450 ° C. for 7 minutes, and then in 5 minutes. After cooling to room temperature, a brown polyimide film having a thickness of 25 μm was obtained. This polyimide film was slit to a width of 500 mm to obtain a multilayer polyimide film. The thickness ratio of (a) / (b) in this multilayer polyimide film is 0.1 / 1. The obtained multilayer film was embedded in an epoxy resin, cut with a microtome so that the film cross section could be observed, and the cross section was observed with a scanning electron microscope. In the electron microscopic image of the cross section, the boundary between the layers having different compositions could be observed in a striped manner, and the thickness ratio coincided with the thickness ratio obtained from the coating thickness.
The obtained green film was heated in a continuous drying oven at 170 ° C. for 3 minutes, then heated to 450 ° C. in about 20 seconds and heated at 450 ° C. for 7 minutes, and then in 5 minutes. After cooling to room temperature, a brown polyimide film having a thickness of 25 μm was slit into a width of 500 mm.
The peel strength was defined as the strength required when the multilayer polyimide film to be measured was peeled off in the 90-degree direction. The measurement was performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph (registered trademark) model name AG-5000A) according to JIS C6418.
The above-mentioned film is mounted on a continuous sputtering apparatus, using a target of a frequency of 13.56 MHz, an output of 400 W, a gas pressure of 0.8 Pa, a nickel-chromium (chromium content 10%) alloy, and RF sputtering in a xenon atmosphere. By the method, a nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / sec. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Thereafter, this film is cut out to 250 mm × 400 mm, fixed to a plastic frame, and a thick copper plating layer having a thickness of 5 μm is formed on the copper thin film using a copper sulfate plating bath. A film was obtained.
After the metallized polyimide film to be measured was processed into a TAB tape pattern having a wiring width of 90 μm, the peel strength was defined as the strength required when peeled off in the 90 ° direction. The measurement was performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph (registered trademark) model name AG-5000A) according to JIS C6418.
Tables 1 and 2 show the physical properties of the multilayer film and the evaluation of the metallized polyimide film.
In addition, the polyimide film was similarly manufactured using the polyamic-acid solution (I) similarly to the single layer film, The linear expansion coefficient is 1.5 ppm / degrees C, Tensile breaking strength is 390 MPa, Tensile modulus is It was 6.8 GPa.

(Comparative Example 1)
The above-mentioned polyamic acid solution (I) and silane-modified polyamic acid (C) were coated on a stainless steel belt in the same manner as in Example 2 and coated using a T-die. The die lip gap was 150 μm skin layer and 500 μm core layer. Next, the polyamic acid film having self-supporting property obtained by drying at 90 ° C. for 60 minutes was peeled from the stainless steel belt to obtain a green film having a thickness of 40 μm.
The obtained green film was heated in a continuous drying oven at 170 ° C. for 3 minutes, then heated to 450 ° C. in about 20 seconds and heated at 450 ° C. for 7 minutes, and then in 5 minutes. After cooling to room temperature, a brown polyimide benzoxazole film having a thickness of 25 μm was obtained. This polyimide benzoxazole film was slit to a width of 500 mm to obtain a multilayer polyimide film. The thickness ratio of (a) / (b) in this multilayer polyimide film is 0.1 / 1. The obtained multilayer film was embedded in an epoxy resin, cut with a microtome so that the film cross section could be observed, and the cross section was observed with a scanning electron microscope. In the electron microscopic image of the cross section, the boundary between the layers having different compositions can be observed in a striped pattern, and the thickness ratio is almost the same as the thickness ratio obtained from the coating thickness.
The above-mentioned film is mounted on a continuous sputtering apparatus, using a target of a frequency of 13.56 MHz, an output of 400 W, a gas pressure of 0.8 Pa, a nickel-chromium (chromium content 10%) alloy, and RF sputtering in a xenon atmosphere. By the method, a nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / sec. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Thereafter, this film is cut out to 250 mm × 400 mm, fixed to a plastic frame, and a thick copper plating layer having a thickness of 5 μm is formed on the copper thin film using a copper sulfate plating bath. A film was obtained.
Tables 1 and 2 show the physical properties of the multilayer film and the evaluation of the metallized polyimide film.

(Example 2)
The above polyamic acid solution (b) is spin-coated on a silicon wafer with a spin coater, dried at 120 ° C. for 5 minutes using a hot plate, and further subjected to heat treatment at 200 ° C. for 30 minutes and at 400 ° C. for 60 minutes. And a polyimide film was obtained.
Table 3 shows the results of a cross-cut test performed on this film.
(Comparative Example 2)
The above polyamic acid solution (c) is spin-coated on a silicon wafer with a spin coater, dried at 120 ° C. for 5 minutes using a hot plate, and further subjected to heat treatment at 200 ° C. for 30 minutes and at 400 ° C. for 60 minutes. And a polyimide film was obtained.
Table 3 shows the results of a cross-cut test performed on this film.

(Physical properties of multilayer film)

(Evaluation of metallized polyimide film)

  As described above, the polyamic acid (1) having a diamine residue having a benzoxazole skeleton of the present invention, an epoxy compound (A) having one hydroxyl group in one molecule, and an alkoxysilane partial condensate (B) The alkoxy group-containing silane-modified polyamic acid obtained by reacting with the epoxy group-containing alkoxysilane partial condensate (2) obtained by dealcoholization reaction with silane-modified polyamic acid resin composition containing a polar solvent is heat resistant. Further, a transparent polyimide-silica hybrid cured product having excellent mechanical strength and insulating properties can be provided. A laminate in which a layer of a silane-modified polyimide obtained by drying and curing this resin composition and a substrate or film base material having a low linear expansion coefficient in a specific range has excellent bondability between them, warping, cracking For example, it is extremely useful as a laminated material in a flexible printed circuit board and the like without causing peeling.

Claims (4)

  Epoxy group obtained by dealcoholization reaction of polyamic acid (1) having diamine residue having benzoxazole skeleton, epoxy compound (A) having one hydroxyl group in one molecule and alkoxysilane partial condensate (B) A silane-modified polyamic acid resin composition comprising an alkoxy group-containing silane-modified polyamic acid obtained by reacting the containing alkoxysilane partial condensate (2) and a polar solvent.   The silane-modified polyamic acid resin composition according to claim 1, wherein the silane-modified polyamic acid resin composition is used by being applied to the surface of an organic substrate or an inorganic substrate having a linear thermal expansion coefficient (CTE) of 0 ppm / ° C or more and 20 ppm / ° C or less.   The silane-modified polyamic acid resin composition according to claim 1, wherein the silane-modified polyamic acid resin composition is used by being applied to the surface of a silicon wafer.   The silane-modified polyamic acid resin composition according to claim 1, wherein the silane-modified polyamic acid resin composition is used by being applied to the surface of a polyimide film having a diamine residue having a benzoxazole skeleton.