JP2010155975A - Polyimide resin, method for producing the same, adhesive composition using the same, adhesive sheet, printing ink composition, and printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition having heat resistance, low-temperature adhesiveness, and insulation reliability at the same time, in particular, an adhesive composition useful for a printed circuit board, a sheet of the adhesive composition, a printing ink, and a printed circuit board using these. <P>SOLUTION: A polyimide resin, which has an acid value of 30-300 eq/10<SP>6</SP>g, is prepared by graft-polymerizing a radical-polymerizable monomer with a polyimide resin, which is prepared by copolymerizing one or more compounds selected from the group consisting of an aliphatic polyester having a carboxyl group or a hydroxyl group at the terminus, a butadiene rubber and a dimer acid. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a novel polyimide resin, preferably a polyamideimide resin, a method for producing the polyimide resin, an adhesive composition, an adhesive sheet, a printing ink composition, and a printed circuit board using the polyimide resin. More preferably, the present invention relates to a heat-resistant adhesive composition, an adhesive sheet, a printing ink composition, and a printed circuit board using these, which are excellent in workability because they dissolve in a low-boiling solvent.

Conventionally, as a heat-resistant adhesive, a material mainly composed of a polyimide resin or an epoxy resin has been used, but there are some problems in using these resins.
One of them is that it was difficult to achieve both heat resistance and low temperature adhesion. That is, conventionally, a polyimide-based adhesive has excellent heat resistance, so that a strong heating facility for bonding at a high temperature is required. On the other hand, an epoxy-based adhesive that can be bonded at a low temperature has a problem of poor heat resistance.
Several specific methods for achieving both the low-temperature adhesiveness and the heat resistance have been proposed. For example, there are methods such as using a heat-resistant epoxy resin and a maleimide resin, but these resins are fragile due to their high curing density, and therefore their use is limited. In addition, Patent Document 1 shows that an epoxy resin is blended with a polyetherimide having a specific structure to achieve both low-temperature adhesion and heat resistance. If this is the case, an adhesive temperature of 200 ° C. is necessary, and it cannot be said that the adhesiveness is sufficiently low. Polyamideimide heat-resistant adhesives have also been proposed. For example, Patent Document 2 and Patent Document 3 disclose polyamideimides copolymerized with acrylonitrile-butadiene and adhesives for semiconductors using the same. Patent Document 5 proposes a polyamideimide copolymerized with dimer acid and an adhesive for semiconductors using the same, but the former is excellent in low-temperature adhesion and solder resistance, but copper under high temperature and high humidity. The circuit portion of the foil has a drawback that it tends to cause migration by generating dendrites, and the latter has the disadvantage that the adhesiveness is insufficient due to the lack of flexibility of the resin.
Furthermore, Patent Document 6 proposes an invention in which an acrylic monomer is graft-polymerized on a polyamideimide resin. This patent is a content for obtaining an aqueous dispersion, and is an adhesive for printed circuit boards that is an object of the present invention. However, it is insufficient in terms of water resistance and insulation reliability based thereon.

JP-A 63-99280 JP-A-11-021455 JP2001-011421 JP-A-11-021454 JP 2001-011420 A JP-A-2005-213397

The present invention relates to a polyimide resin having both heat resistance, low-temperature adhesiveness and insulation reliability, an adhesive composition using the resin, particularly an adhesive composition useful for a printed circuit board, a sheet thereof, and a printing ink Furthermore, the present invention provides a printed circuit board using these.

That is, the present invention
(1)
A radical polymerizable monomer is graft-polymerized on a polyimide resin in which at least one selected from the group consisting of aliphatic polyester having a carboxyl group or a hydroxyl group at the terminal, butadiene rubber and dimer acid is copolymerized, and the acid value is Polyimide resin which is 30-300 eq / 10 ⁶ g.
(2)
The polyimide resin according to (1), wherein the polyimide resin has an isophorone and / or dicyclohexylmethane residue as an amine component.
(3)
The polyimide resin according to (1) or (2), wherein the polyimide resin has a cyclohexane residue as an acid component.
(4)
When the total acid component is 100 mol%, a polyimide resin obtained by copolymerizing 0.5 to 20 mol% of a polymerizable unsaturated group-containing dicarboxylic acid and a radical polymerizable monomer, γ-butyrolactone, cyclohexanone, The polyimide resin according to any one of (1) to (3), wherein the reaction is performed in one or more solvents selected from the group consisting of cyclopentanone, tetrahydrofuran, ethanol, butanol, toluene, and xylene. Production method.
(5)
An adhesive composition in which at least one selected from the group of polyfunctional epoxy, melamine and isocyanate compounds is blended with the polyimide resin according to any one of (1) to (3).
(6)
An adhesive sheet obtained from the adhesive composition according to (5).
(7)
An ink composition for printing, in which one or more selected from the group of polyfunctional epoxy, melamine and isocyanate compounds and inorganic or organic fine particles are mixed with the polyimide resin according to any one of (1) to (3).
(8)
A printed circuit board using the adhesive composition according to (5).
It is about.

The polyimide resin of the present invention is a radically polymerizable monomer that is graft-polymerized, and can impart flexibility, adhesion, toughness, self-crosslinking property, water resistance, and inherent heat resistance and chemical resistance of the polyimide resin. It can also have characteristics such as sex.
For this reason, when used in coating agents, paints, adhesives, screen printing inks, etc., insulation reliability such as water resistance, chemical resistance, heat resistance, low temperature adhesion, migration resistance under high temperature and high humidity, etc. A coating film having excellent properties can be formed.

The present invention is described in detail below.
The present invention relates to a polyimide resin excellent in heat resistance, low-temperature adhesion, insulation reliability, etc., a method for producing the polyimide resin, an adhesive composition using the polyimide resin, an adhesive sheet, a printing ink composition, and The present invention relates to a printed circuit board.
Of the polyimide resins used in the present invention, particularly preferred are polyamideimide resins, which can be produced by a known method such as an acid chloride method or an isocyanate method.

The polyimide resin of the present invention is a radical polymerizable monomer obtained by copolymerizing at least one selected from the group consisting of an aliphatic polyester having a carboxyl group or a hydroxyl group at a terminal, a butadiene rubber and a dimer acid. Is graft polymerized with an acid value of 30-300 eq / 10 ⁶ g
Is a polyimide resin. The acid value of the polyimide resin after graft polymerization is 3
It is 0-300 eq / 10 ⁶ g, preferably 110-300 eq / 10 ⁶ g, more preferably 120-220 eq / 10 ⁶ g. If the acid value exceeds 300, it is not desirable from the viewpoint of migration resistance, and if it is less than 30, curing does not proceed when a crosslinking agent is mixed later, and it is not desirable from the viewpoint of solder resistance and migration resistance.
The polyimide resin of the present invention is a polyimide resin in which one or more selected from the group consisting of aliphatic polyesters having a carboxyl group or a hydroxyl group at the terminal, a butadiene rubber and a dimer acid are copolymerized on a part of the acid component, The reason for the clear polymerization is not clear because the radical polymerizable monomer is graft polymerized, but the adhesion is improved and the migration resistance is improved by setting the acid value within the above range. I found. When the radically polymerizable monomer is graft polymerized by copolymerization of the above polyester, butadiene rubber, and dimer acid, it is easily compatible with the polyimide resin and is considered to play a role as a so-called compatibilizer. And uniform film formation is possible.

The butadiene rubber used in the present invention is, for example, a polybutadiene having a terminal hydroxyl group or a carboxyl group, polyacrylonitrile-butadiene, polystyrene-butadiene, etc., and Ube Industries' CTB, CTBN series, etc. can be suitably used.
The aliphatic polyester may be obtained from an aliphatic dicarboxylic acid and a diol or ring-opening polymerization of a cyclic lactone. The aliphatic dicarboxylic acid is not particularly limited, and specific examples include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Also, the diol is not particularly limited, and specific examples include ethylene glycol, propylene glycol, butanediol, hexanediol and the like. These may be used alone or in combination of two or more. Further, it may be a polylactone obtained by ring-opening polymerization of a cyclic lactone. Specific examples include γ-butyrolactone, δ-valerolactone, ε-caprolactone, and the like.

In this case, the number average molecular weight of the aliphatic polyester or butadiene rubber is preferably 500 or more, and more preferably 1000 or more. The upper limit of these molecular weights is not particularly limited, but is preferably 30000 or less, more preferably 10,000 or less from the viewpoint of compatibility with polyimide resin, reactivity, and the like. When the number average molecular weight is less than 500, the compatibility between the polyimide resin and the graft polymer tends to be insufficient, and the transparency of the resulting film tends to be lowered, and it may be difficult to form a uniform film.
The copolymerization amount of aliphatic polyester, butadiene rubber and dimer acid is selected depending on the structure of the polyimide resin, the desired properties, and the type and amount of the radical polymerizable monomer to be graft polymerized. It is preferable to be copolymerized in an amount of 1 to 70% by weight, more preferably 3 to 30% by weight. If it is less than 1% by weight, it tends to be difficult to improve the compatibility, and if it exceeds 70% by weight, heat resistance and adhesiveness tend to be lowered.

As the acidic component used in the production of the polyimide resin of the present invention, trimellitic acid and its anhydride, chloride are mainly used in addition to the above aliphatic polyester, butadiene rubber, and dimer acid. Includes tetracarboxylic acids such as pyromellitic acid, biphenyltetracarboxylic acid, biphenylsulfonetetracarboxylic acid, benzophenonetetracarboxylic acid, biphenylethertetracarboxylic acid, ethene glycol bistrimellitate, and propylene glycol bistrimellitate , Oxalic acid, adipic acid, malonic acid, sebacic acid, azelaic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 4,4 '' ''-dicyclohexylmethanedicarboxylic acid, dimer Such as aliphatic, alicyclic dicarboxylic acid, terephthalic acid, isophthalic acid, diphenylsulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, naphthalenedicarboxylic acid and the like, among these, reactivity, heat resistance, Trimellitic anhydride is preferable from the viewpoint of adhesiveness and the like, and it is desirable to replace a part thereof with dicarboxypoly (acrylonitrile-butadiene), dicarboxypolybutadiene, aliphatic polyester and the like. From the viewpoint of improving solubility in a low-boiling solvent and improving heat resistance, it is preferable to have a cyclohexane residue as the acid component.

Diamines (diisocyanates) used for the production of polyimide resins include aliphatic diamines such as ethylenediamine, propylenediamine, and hexamethylenediamine, and diisocyanates thereof, isophorone diamine, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 4 , 4 ″ ″-dicyclohexylmethanediamine and the like and their diisocyanates, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4 ″ ″-diamino Aromatic diamines such as diphenyl ether, 4,4′-diaminodiphenyl sulfone, benzidine, o-tolidine, 2,4-tolylenediamine, 2,6-tolylenediamine, xylylenediamine, naphthalenediamine, and the like Among them, 4,4′-diaminodiphenylmethane (diisocyanate), isophoronediamine (diisocyanate), and 4,4 ″ ″-dicyclohexylmethanediamine (diisocyanate) are used in view of solubility and transparency. preferable.

The polyimide resin of the present invention can copolymerize a diol component in addition to the acid component and amine (diisocyanate) component. Examples of the diol component include ethylene glycol, propylene glycol, tetremethylene glycol, butanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyester diol, and carbonate diol. Among these, compatibility as shown above, From the viewpoint of adhesiveness, polyester diols, particularly aliphatic polyester diols are preferred.

In order to graft the radical polymerizable monomer to the polyimide resin of the present invention, it is preferable to copolymerize or modify the radical polymerizable component in the polyimide resin in order to increase the graft efficiency. Examples of these comonomers include polymerizable unsaturated group-containing dicarboxylic acids such as fumaric acid and maleic acid, and examples of the modifying agent include acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydroxyethyl acrylate, itaconic acid, Examples thereof include glycidyl methacrylate, acrylamide, N-methylol acrylamide, maleic anhydride, etc. Among them, fumaric acid is preferable as a copolymerization monomer, and glycidyl methacrylate is preferable as a modifier.

  The copolymerization amount of the radical polymerizable component or the modifying agent is preferably 0.5 to 20 mol%, more preferably 3 to 10 mol%, and still more preferably when the total acid component is 100 mol%. 4-7 mol%. If it is less than 0.5 mol%, there is a possibility that the graft polymerization will not be sufficiently performed, and a homopolymer tends to be easily formed. On the other hand, if it exceeds 20 mol%, the properties of the polyimide resin may not be sufficiently exhibited, and it tends to be unfavorable because it tends to gel during graft polymerization.

The polyimide resin of the present invention may be an aprotic polar solvent such as N, N ″ ″-dimethylformamide, N, N′-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, isophorone, cyclohexanone, cyclopenta It can be produced by stirring while heating at 60 ° C. to 200 ° C. in one or two or more solvents of ketones such as non, aromatic hydrocarbons such as xylene. In order to accelerate the reaction, alkali metals such as sodium fluoride, potassium fluoride and sodium methoxide, amines such as triethylamine, diethanolamine and diazabicycloundecene, and catalysts such as dibutyltin dilaurate can be used. .

The polyimide resin thus produced has a glass transition temperature of preferably 50 ° C. or higher, more preferably 80 ° C. or higher, and a logarithmic viscosity of 0.1 dl / g or higher, more preferably from the application of the present invention. Is 0.2 dl / g or more. When the glass transition temperature is less than 50 ° C., the inherent heat resistance of the polyimide resin is deteriorated, and when the logarithmic viscosity is less than 0.1 g / dl, the coating film becomes brittle and may not be practical.

Next, the polyimide resin of the present invention is graft-polymerized with a radical polymerizable monomer. The graft polymerization can be performed in a polymerization solution of the polyimide resin, but the polymerization solution can be used in place of another solvent. When changing the polyimide polymerization solution to another solvent, the polyimide resin polymerization solution is poured into a solvent immiscible with polyimide resin such as water or alcohol to solidify, and the washed and dried resin is dissolved in the other solvent. Used. These solvents include alcohols such as methanol, ethanol and butanol, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as tetrahydrofuran, dioxane and carbitol, acetone, methyl ethyl ketone, cyclopentanone and cyclohexanone. 1 type, or 2 or more types of mixed solvents, such as ketones, can be used. In particular, the reaction is preferably carried out in one or more solvents selected from the group consisting of γ-butyrolactone, cyclohexanone, cyclopentanone, tetrahydrofuran, ethanol, butanol, toluene and xylene.

As radically polymerizable monomers to be grafted onto polyimide resins, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and esters of acrylic acid and methacrylic acid Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, Methacrylic acid-n-butyl, isobutyl methacrylate, methacrylic acid-2-hydroxyethyl, methacrylic acid-n-hexyl, lauryl methacrylate, etc., acrylonitrile, methacrylonitrile, acrylamide, N-methylol acryl Amides, glycidyl acrylate, glycidyl methacrylate, diacetone acrylamide, vinyl acetate, vinyl ethers, N- vinylpyrrolidone, styrene, alpha-methyl styrene, t- butyl styrene, can be exemplified vinyl toluene.
Moreover, a part of these monofunctional unsaturated monomers can be replaced with polyfunctional unsaturated monomers. For example, divinylbenzene, ethylene glycol diacrylate, propylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, glycerin triacrylate, trimethylolpropane triacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate And dipentaerythritol hexaacrylate.

Among the above radical polymerizable monomers, those having a relatively long alkyl length such as ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate are used from the viewpoints of flexibility, adhesion, and water resistance. It is preferable.

The radical polymerizable monomer is preferably selected so that the acid value of the entire polyimide resin is 30 to 300 eq / 10 ⁶ g.

The graft polymer of the polyimide resin can be efficiently obtained by graft polymerization of a radical polymerizable monomer to the unsaturated double bond in the polyimide resin.
In the present invention, a solution obtained by dissolving a polyimide resin in an organic solvent is added by adding a radical initiator, a radical polymerizable monomer and, if necessary, a chain transfer agent such as a thiol compound, and heating and stirring. . The radical initiator and the radical polymerizable monomer may be added at the same time for graft polymerization, or may be added separately. Moreover, you may add a radically polymerizable monomer, dropping over time.

The embodiment of the present invention will be further described. In the present invention, first, a polyimide resin polymerization solution or a redissolved solution is prepared. In this case, the solvent to be used is not particularly limited as long as it can dissolve the polyimide resin, but a solvent having a low boiling point and easy to dry is preferable, and the solid content concentration is preferably 20 to 70% by weight. It is preferable to add a radical polymerization initiator and a radical polymerizable monomer to the polyimide resin solution, and perform heating and stirring. The addition amount of the radical polymerizable monomer is preferably 5 to 60% by weight, more preferably 7 to 45% by weight, and still more preferably 10 to 40% by weight in the total solid content.
If the addition amount of the radical polymerizable monomer exceeds 60% by weight, the heat resistance inherent to the polyimide resin is impaired, and if it is less than 5% by weight, good adhesion tends to be difficult to obtain.

The radical polymerization initiator is not particularly limited, and commonly known organic peroxides and organic azo compounds can be used. For example, benzoyl peroxide, t-butyl peroxypivalate, 2,2 ′ ″ '-Azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile) and the like can be exemplified. The amount of these radical polymerization initiators used is preferably 0.2% or more, more preferably 0.5% or more, based on the radical polymerizable monomer.

A solution containing a radical polymerization initiator and a radical polymerizable monomer in a polyimide resin solution can usually be graft-polymerized while stirring at 50 to 120 ° C.
The polyimide resin graft polymer of the present invention is not only a graft polymer between a desired polyimide resin and radical polymerizable monomer mixture, but also a polyimide resin itself or a radical polymerizable monomer itself which has not been graft polymerized. These polymers are also included, but those containing these non-grafted polymers are also included within the range that does not hinder the achievement of the object of the present invention.

Moreover, a flame retardant, a pigment, a dye, an antifoaming agent, an antistatic agent, a leveling agent, etc. can be mix | blended with the graft-polymerized polyimide resin of this invention as needed.

The graft-polymerized polyimide resin of the present invention can be used as a vehicle for paints, inks, coating agents, adhesives, or as a processing agent for fibers, films, papers, etc. It is useful as an agent and an adhesive sheet.

In addition, the graft-polymerized polyimide resin of the present invention can be used as it is, but by adding a cross-linking agent, higher water resistance, adhesion and heat resistance can be imparted.
Examples of the crosslinking agent include phenol-formaldehyde resin, amino resin, polyfunctional epoxy resin, melamine-formaldehyde resin, polyfunctional isocyanate compound and the like.

The adhesive composition of the present invention includes one or more compounds selected from the group consisting of a polyfunctional epoxy compound, a polyfunctional isocyanate compound, and a melamine compound on the graft-polymerized polyimide resin synthesized as described above. In addition, higher water resistance, adhesion and heat resistance can be further imparted.
There is no restriction | limiting in particular as a polyfunctional epoxy compound combined with the polyimide resin of this invention, Bisphenol A diglycidyl ether, a phenol novolak-type epoxy compound, an amine-type epoxy compound, etc. are mentioned. From the viewpoint of compatibility with the polyimide resin and the crosslinking density, a phenol novolac type epoxy compound is particularly preferable.
The polyfunctional isocyanate compound is not limited, and examples include tolylene diisocyanate to trimethylolpropane, isophorone diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate triadduct, and hexamethylene diisocyanate cyclic trimer. From the viewpoint of adhesion, a cyclic trimer of hexamethylene diisocyanate is particularly preferable.
Examples of the melamine compound include trimethylolmelamine methyl ether and butyl ether.
These cross-linking agents such as polyfunctional epoxy compounds, polyfunctional isocyanate compounds, and melamine compounds are preferably blended in an amount of 3 to 200 parts by weight, more preferably 10 to 100 parts, per 100 parts by weight of the polyimide resin. It is preferable to mix in the range of parts by weight. When the blending amount of the crosslinking agent is less than 3 parts by weight, heat resistance and chemical resistance such as humidified solder may be insufficient, and when it exceeds 200 parts by weight, the film becomes hard and brittle, resulting in a decrease in adhesion. There is.

In addition, for these crosslinking agents, as curing aids and catalysts, for example, in the case of epoxy compounds, polyvalent carboxylic acids and their anhydrides, imidazole compounds, amine-based catalysts, and in the case of isocyanate compounds, dibutyltin. A metal compound such as dilaurate or a catalyst such as p-toluenesulfonic acid can be used in the case of a melamine compound.

  When using the polyimide resin of the present invention and a composition in which a crosslinking agent such as a polyfunctional epoxy compound, a polyfunctional isocyanate compound, or a melamine compound is blended as an adhesive or a coating agent, it is organic or organic to impart flame retardancy. An inorganic phosphorus compound can be blended. There is no particular limitation on the phosphorus compound, and phosphoric acid esters and phosphazenes such as red phosphorus, various inorganic phosphates such as sodium phosphate, magnesium phosphate, and calcium phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, and phosphate ester condensates. Examples thereof include phosphazene compounds from the viewpoint of moisture resistance. A phosphorus compound can be added so that the phosphorus content is 1% by weight or more and 3% by weight or less based on the solid content of the adhesive composition. If it is less than 1 weight, it tends to be difficult to obtain a flame-retardant effect.

  The use of the composition containing the polyimide resin of the present invention and a crosslinking agent such as a polyfunctional epoxy compound, a polyfunctional isocyanate compound, and a melamine compound is not particularly limited, but the most useful use is an adhesive for printed circuit boards, Insulating ink for adhesive sheet and circuit protection. Specifically, adhesives for bonding copper foil or aluminum foil to insulating substrates such as polyimide film, polyester film, glass-epoxy sheet, phenolic resin sheet, coverlay film adhesive, coverlay, etc. Examples thereof include insulating ink for protection, an adhesive for reinforcing a part of a circuit board with a reinforcing plate, an adhesive for mounting a semiconductor chip directly on the circuit board, and the like.

  In the heat-resistant adhesive composition of the present invention, a silicone compound, an aluminum hydroxide, a flame retardant other than inorganic and organic pigments, dyes, antistatic agents, leveling agents, and phosphorus compounds as long as the content of the present invention is not impaired Urea compounds and the like and resins other than polyimides, for example, polyesters, polyamides, polyurethanes, and the like can be appropriately blended.

As one of the methods of using the heat-resistant adhesive of the present invention, a solution in which a crosslinking agent or an additive is mixed with a polyimide resin solution is applied to an adherend, dried and then superimposed on the other adherend and heated. Examples of the method include pressure bonding with a roll or a heat press and, if necessary, heat curing treatment.
In this case, if the solvent remains in the adhesive layer, it may cause undesired results due to firing at the time of adhesion processing or a decrease in heat resistance itself. As described above for the production of the polyimide resin, it is preferable to use a polymer having a high boiling point polymerization solvent replaced with a low boiling point solvent such as alcohol, aromatic hydrocarbon, ether or ketone.

<Ink composition for printing>
When the polyimide resin of the present invention is used as a printing ink composition, a mixed solution of a polyimide resin and a crosslinking agent, inorganic particles such as silicon oxide and calcium sulfate and / or various organic fine particles are added to the polyimide resin and the aforementioned It is preferable to mix and disperse 0.5 to 10% by weight with respect to the mixed solution of the crosslinking agent, more preferably 1 to 5% by weight. The thixo index represented by the ratio is 1.2 or more and 3.0 or less, preferably a silicone or acrylic antifoaming agent or leveling agent is 0.5 to 5 with respect to the mixture of the polyimide resin solution and the crosslinking agent. It can be used in combination by weight%.

<Adhesive sheet>
The adhesive sheet refers to an adhesive sheet having the adhesive composition of the present invention as an adhesive layer and having at least one or more peelable protective films. For example, a two-layer structure of protective film layer / adhesive layer or a three-layer structure of protective film layer / adhesive layer / protective film corresponds to this. The protective film layer here is not particularly limited as long as it can be peeled without impairing the form of the adhesive layer, but examples thereof include polypropylene film, polyester film, silicone, wax-treated polyester film, and paper. In addition, metals, ceramics, and the like can be used, and there is an advantage that new functions such as heat dissipation, electromagnetic shielding, reinforcement, and identification can be added as well as protection for the purpose of surface insulation and environmental resistance.
The heat-resistant adhesive composition solution of the present invention is applied to a release substrate such as a polypropylene film, a polyester film, a silicone film, a wax-treated polyester film, or paper, and then dried, preferably in the same manner as the above coverlay film The adhesive film or sheet in a semi-cured state is sandwiched between two types of adherends, heated and pressed with a heating roll or a heat press, and cured if necessary.
Also in this case, as in the coating method, it is preferable to use a sheet dissolved in a low boiling point solvent in order to obtain a sheet having no residual solvent.
The thickness of the adhesive sheet may be appropriately selected depending on the use, but is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of ease of manufacturing the sheet and workability of adhesion. . Further, from the viewpoint of ease of production of the sheet and production cost, it is preferably 50 μm or less, and more preferably 30 μm or less.

<Printed circuit board>
The adhesive composition of the present invention can be used as an adhesive for printed circuit boards. Specifically, adhesives for bonding copper foil and aluminum foil to polyimide film, polyester film, glass-epoxy sheet, phenol resin sheet insulation base material, adhesive for coverlay film, part of circuit board is reinforced Examples thereof include an adhesive for reinforcing with a plate and an adhesive for mounting a semiconductor chip directly on a circuit board.
As the copper foil, a rolled copper foil or an electrolytic copper foil conventionally used for printed circuit boards can be used.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples.
In addition, the measured value in an Example is a value measured with the following method.
1. Glass transition temperature The adhesive solution was applied to a polypropylene film so that the dry film thickness was about 30 μm, dried, and then peeled off from the polypropylene film, using a dynamic viscoelasticity measuring device manufactured by AIT measurement control Co., Ltd., 110 Hz. Measurement was performed at a frequency, and the value was obtained from the inflection point of the storage elastic modulus.
Logarithmic viscosity A solution of 0.5 g of dried polymer in 100 ml of NMP was measured at 30 ° C. using an Ubbelohde viscosity tube.
・ Acid value To a solution of 0.4 g of polymer dissolved in 20 ml of DMF, 2 to 3 drops of thymolphthalein test solution and a solution of 0.568 g of sodium methoxide dissolved in 100 ml of methanol were added dropwise and titrated from the color change. .

<Synthesis of Polyamideimide Resin A>
In a flask equipped with a condenser, a nitrogen inlet tube, and a stirrer, 0.9 mol of trimellitic anhydride (TMA), 0.05 mol of fumaric acid, dicarboxypoly (acrylonitrile-butadiene) (CTBN 1300 × 13 manufactured by Ube Industries) 0.05 mol, 1 mol of diphenylmethane-4,4′-diisocyanate (MDI) and 0.02 mol of potassium fluoride were charged together with N-methyl-2-pyrrolidone (NMP) to a solid content concentration of 30%. The reaction was performed at 2 ° C. for 2 hours and at 180 ° C. for 5 hours, and then cooled to 80 ° C. The obtained polyamideimide resin had a logarithmic viscosity of 0.55 dl / g and a glass transition temperature of 205 ° C.
A flask equipped with a cooler and a stirrer was charged with 100 g of this polyamideimide resin solution, heated to 80 ° C. and stirred, with 10 g of ethyl acrylate, 0.6 g of azobisisobutyronitrile (AIBN), 1-octane While adding 0.06 g of the thiol ester compound in 12 g of NMP dropwise over 60 minutes, the polymerization reaction was performed with the graph. The acid value was 126 eq / 10 ⁶ g.

<Synthesis of Polyamideimide Resin B>
Using the same equipment as above, TMA 0.4 mol, 1,4 cyclohexanedicarboxylic acid 0.4 mol, fumaric acid 0.05 mol, dimer acid 0.15 mol, potassium fluoride 0.02 mol, IPDI 1.02 mol Was added together with γ-butyrolactone so that the solid content concentration was 50%, reacted at 180 ° C. for 3 hours, and then NMP was added while cooling to dilute the solid content concentration to 20%. This solution was poured into water to obtain a white solid resin. This polyamideimide resin had a logarithmic viscosity of 0.53 dl / g and a glass transition temperature of 215 ° C. Furthermore, butyl acrylate 6.7 g, AIBN 0.4 g, 1-octane thiol ester 0.04 g and ethanol were added to 100 g of a solution in which this solid resin was dissolved in a mixed solvent of equal amounts of toluene and ethanol so that the solid content was 20%. A mixed solution of 8 g of a mixed solvent of equal amounts of toluene and toluene was added dropwise over 60 minutes while heating to 70 ° C. and stirring to prepare acrylic guft PAI. The acid value was 161 eq / 10 ⁶ g.

<Synthesis of Polyamideimide Resin C>
Using the same apparatus as above, TMA 0.85 mol, maleic acid 0.05 mol, polycaprolactone (Placcel 220 manufactured by Daicel Corporation) 0.1 mol, MDI 0.525 mol, 2,4-tolylene diisocyanate 0.525 Mole, 0.02 mol of potassium fluoride was added together with cyclopentanone so that the solid concentration was 50%, reacted at 110 ° C. for 5 hours, and then cooled to a solid concentration of 30% while cooling. Diluted with non. This polyamideimide resin had a logarithmic viscosity of 0.35 dl / g and a glass transition temperature of 135 ° C.
Using this polyamideimide resin solution, ethyl acrylate was graft-polymerized under the same conditions as in the polyamideimide resin A. The acid value was 218 eq / 10 ⁶ g.

<Synthesis of Polyamideimide Resin D>
Using the same apparatus as described above, TMA 0.65 mol, Byron 220 (Toyobo Co., Ltd., molecular weight 2000 polyester diol) 0.3 mol, fumaric acid 0.05 mol and IPDI 1.02 mol, potassium fluoride 0. 02 mol was added together with γ-butyrolactone so that the solid concentration was 50%, reacted at 180 ° C. for 5 hours, and then diluted with NMP so that the solid concentration was 25% while cooling. This solution was poured into water to obtain a white solid resin. This polyamideimide resin had a logarithmic viscosity of 0.38 dl / g and a glass transition temperature of 125 ° C. Furthermore, this solid resin was dissolved in tetrahydrofuran so that the solid content concentration was 25%.
100 g of this resin solution was heated to 65 ° C. and stirred, and a solution prepared by dissolving 8.3 g of butyl acrylate, 0.5 g of AIBN, and 0.05 g of 1-octanethiol ester in 10 g of tetrahydrofuran was dropped over 60 minutes. . The acid value was 205 eq / 10 ⁶ g.

<Synthesis of polyamideimide resin F>
Using the same apparatus as described above, 1 mol of TMA and 1 mol of diphenylmethane-4,4′-diisocyanate were charged together with NMP so that the solid concentration was 20%, and reacted at 120 ° C. for 1 hour and at 180 ° C. for 3 hours. . The logarithmic viscosity of the obtained polymer was 0.80 dl / g. The acid value was 98 eq / 10 ⁶ g.

<Synthesis of polyamideimide resin G>
Using the same apparatus as above, 1 mol of TMA, 1 mol of IPDI and 0.02 mol of potassium fluoride were charged together with γ-butyrolactone so that the solid content concentration would be 50%, reacted at 180 ° C. for 5 hours, then cooled. However, it was diluted with NMP so that the solid content concentration was 20%. This solution was poured into water to obtain a white solid resin. This polyamideimide resin had a logarithmic viscosity of 0.28 dl / g and a glass transition temperature of 290 ° C. This white solid resin was dissolved in tetrahydrofuran so that the solid concentration was 25%. The acid value was 308 eq / 10 ⁶ g.

<Synthesis of Polyamideimide Resin I>
Using the same apparatus as above, TMA 0.9 mol, fumaric acid 0.1 mol and IPDI 1.02 mol were charged together with γ-butyrolactone so that the solid concentration would be 50%, and reacted at 180 ° C. for 5 hours. While cooling, the solution was diluted with cyclohexanone so that the solid content concentration became 25%. The obtained polyamideimide resin had a logarithmic viscosity of 0.35 dl / g and a glass transition temperature of 277 ° C. A solution obtained by dissolving 250 g of this polyamideimide resin solution at 60 ° C. and dissolving 10.67 g of acrylic acid, 6 g of ethyl acrylate, 1 g of azobisisobutyrolactone and 0.3 g of 1-octanethiol ester compound in 20 g of cyclohexanone was 0.2 ml / min. The dropping and grafting reaction were carried out at a rate of The acid value was 2780 eq / 10 ⁶ g.

<Synthesis of Polyamideimide Resin X>
Using the same apparatus as above, TMA 0.87 mol, fumaric acid 0.05 mol, dicarboxypoly (acrylonitrile-butadiene) (Ube Industries CTBN 1300 × 13) 0.03 mol, dimethylolbutanoic acid 0.05 mol , 1 mol of diphenylmethane-4,4′-diisocyanate (MDI) was added together with N, N′-dimethylacetamide (DMAc) so that the solid concentration was 50%, and reacted at 60 ° C. for 2 hours, then 130 ° C. For further 6 hours. Then, it diluted with DMAc so that solid content concentration might be 30%. The obtained polyamideimide resin had a logarithmic viscosity of 0.58 dl / g and a glass transition temperature of 220 ° C. Using this polyamideimide resin, ethyl acrylate was graft-polymerized under the same conditions as in the polyamideimide resin A. The acid value was 290 eq / 10 ⁶ g.

<Synthesis of polyamideimide resin Y>
Using the same apparatus as above, 0.93 mol of TMA, 0.05 mol of fumaric acid, 0.02 mol of dicarboxypoly (acrylonitrile-butadiene) (CTBN 1300 × 13 made by Ube Industries), diphenylmethane-4,4′-diisocyanate (MDI) 1.02 mol was charged together with DMAc so that the solid concentration was 30%, and reacted at 100 ° C. for 2 hours and at 150 ° C. for 5 hours. The obtained polyamideimide resin had a logarithmic viscosity of 1.15 dl / g and a glass transition temperature of 235 ° C. Using this polyamideimide resin, ethyl acrylate was graft-polymerized under the same conditions as in the polyamideimide resin A. The acid value was 34 eq / 10 ⁶ g.

<Example of production of adhesive composition-1>
Adhesive compositions b and d were prepared by blending 3 g of a phenol novolac epoxy compound (Japan Epoxy Epicoat 152) with 100 g of the polyamideimide resins B and D produced above.

<Manufacture example-2 of adhesive composition>
3 g of trifunctional isocyanate compound Coronate EH (manufactured by Nippon Polyurethane) was blended with 100 g of the polyamideimide resin B solution to obtain an adhesive composition b ′.

<Example of production of adhesive sheet>
The adhesive compositions b and d are applied to a 50 μm polypropylene film, dried at 60 ° C. for 5 minutes and 130 ° C. for 10 minutes, and then peeled to obtain adhesive sheets b ″ and d ″ having a thickness of 20 μm. It was.

<Examples 1-3: Lamination Example-1>
Adhesive composition b, d, b ′ was applied to a polyimide film of 12.5 μm with a gap of 100 μm, dried at 60 ° C. for 5 minutes, and then at 130 ° C. for 10 minutes, and then a 1/2 oz electrolytic copper foil was laminated on the adhesive surface. After being laminated with a roll laminator at 180 ° C., it was left in a nitrogen gas oven at 220 ° C. for 10 hours while being wound on a roll to obtain a flexible copper-clad laminate.
The peel strength between the polyimide film and the electrolytic copper foil was measured for this sample with Tensilon manufactured by Toyo Baldwin.
The state when the same sample was floated in a solder bath at 290 ° C. for 30 seconds was observed to evaluate the solder heat resistance. The judgment was as follows.
○: No swelling or peeling.
X: Dandruff or peeling occurred.

<Examples 4 and 5: Lamination Example-2>
A 0.3 mm aluminum plate reinforcing plate is superimposed on the polyimide film surface of the copper-clad laminate prepared using the adhesive composition b via each of the adhesive sheets b ″ and d ″, and heat at 170 ° C. Using a press, pressure bonding was performed at a pressure of 20 kgf / cm ² for 20 minutes. Thereafter, heat treatment was performed for 1 hour under pressure at the same temperature.
The peel strength between the reinforcing plate made of aluminum plate and the polyimide film was measured for this sample using Tensilon manufactured by Toyo Baldwin.
The state when the same sample was floated in a solder bath at 290 ° C. for 30 seconds was observed to evaluate the solder heat resistance. The judgment was as follows.
○: No swelling or peeling.
X: Dandruff or peeling occurred.

<Examples 6 and 7: Lamination Example-3>
Using Toyobo copper-clad laminate Viroflex, the adhesive composition b, d was applied to a circuit board for migration test having a line / space of 70 μm / 70 μm to be about 20 μm, at 60 ° C. for 5 minutes, 130 ° C. And dried at 150 ° C. for 1 hour and cured. A voltage of 10 V was applied between the electrodes in an environment of 80 ° C. and 85% RH, and the insulating properties after being left for 100 hours were evaluated.
◯: Insulation resistance value between lines is 1E + 08Ω or more ×: Insulation resistance value between lines is 1E + 08Ω or less The state when the same sample was floated in a solder bath at 290 ° C. for 30 seconds was observed. The judgment was as follows.
○: No swelling or peeling.
X: Dandruff or peeling occurred.

<Examples of printing ink production>
Polyamideimide resins A, C, and I were added to 100 g each of silicon oxide 3 g, Epicoat 152 3 g, and Floren AC300 0.3 g, and kneaded twice with a three-roll mill to prepare SRIa, SRIc, and SRIi.

<Examples 8 and 9: Printing example>
On the circuit surface of the migration test circuit plate used in Examples 6 and 7, SRIa and SRIc, respectively.
Was printed using a 125 mesh screen, dried at 130 ° C. for 15 minutes, and then heat treated at 180 ° C. for 1 hour.
A voltage of 10 V was applied between the electrodes in an environment of 80 ° C. and 85% RH, and the insulating properties after being left for 100 hours were evaluated.
◯: Insulation resistance value between lines is 1E + 08Ω or more ×: Insulation resistance value between lines is 1E + 08Ω or less The state when the same sample was floated in a solder bath at 290 ° C. for 30 seconds was observed. The judgment was as follows.
○: No swelling or peeling.
X: Dandruff or peeling occurred.

<Examples 10 and 11>
Using polyamideimide resins X and Y, adhesive compositions x and y were prepared in the same manner as in Adhesive Composition Production Example-1, and a flexible copper-clad laminate was obtained in the same manner as in Example 1.
The peel strength between the polyimide film and the electrolytic copper foil was measured for this sample with Tensilon manufactured by Toyo Baldwin.
The state when the same sample was floated in a solder bath at 290 ° C. for 30 seconds was observed to evaluate the solder heat resistance. The judgment was as follows.
○: No swelling or peeling.
X: Dandruff or peeling occurred.

<Examples 12 and 13>
Using Toyobo copper-clad laminate Viroflex, the adhesive composition x, y was applied to a circuit board for migration test with a line / space of 70 μm / 70 μm to be about 20 μm, at 60 ° C. for 5 minutes, 130 ° C. And dried at 150 ° C. for 1 hour and cured. A voltage of 10 V was applied between the electrodes in an environment of 80 ° C. and 85% RH, and the insulating properties after being left for 100 hours were evaluated.
◯: Insulation resistance value between lines is 1E + 08Ω or more ×: Insulation resistance value between lines is 1E + 08Ω or less The state when the same sample was floated in a solder bath at 290 ° C. for 30 seconds was observed. The judgment was as follows.
○: No swelling or peeling.
X: Dandruff or peeling occurred.

<Comparative Examples 1 and 2>
Lamination-1 (Manufacture of copper-clad laminate) and Lamination-2 (Reinforcement plate bonding) using an adhesive composition f prepared by blending 3 g of Epicoat 152 with 100 g of polyamideimide resin F solution and its sheet f '' The adhesive strength and solder heat resistance were evaluated in the same manner as in Examples 1 and 4, respectively.

<Comparative Examples 3 and 4>
Lamination 1 (production of copper-clad laminate) and lamination 2 (reinforcement plate lamination) were performed using an adhesive composition g in which 3 g of Epicoat 152 was blended with 100 g of polyamideimide resin G solution and a sheet g ″ thereof. The adhesive strength and solder heat resistance were evaluated in the same manner as in Examples 1 and 4, respectively.

<Comparative Examples 5 and 6>
A polyamide-imide resin H was produced in the same manner as the polyamide-imide resin A, except that the preparation of the polyamide-imide resin A was changed to 0.9 mol of MDI. The logarithmic viscosity of the obtained resin was 0.08 dl / g. Since this resin has a low molecular weight and does not form a film, the glass transition temperature and tensile elastic modulus could not be measured. A copper-clad laminate was produced using an adhesive composition h in which 3 parts of Epicoat 152 was blended with 100 parts of a 30% solution of this resin (expected to be close to the same polyamideimide resin B). The adhesive strength and solder heat resistance were evaluated in the same manner as in 1.

<Comparative Example 7>
A solder resist ink was prepared using the polyamideimide resin I by the same method as in Example 8, screen printed under the same conditions, and evaluated for solder heat resistance and migration resistance.

<Comparative Example 8>
Using Toyobo copper-clad laminate Viroflex, the adhesive composition g was applied to a circuit board for migration test with a line / space of 70 μm / 70 μm to be about 20 μm, 5 minutes at 60 ° C., 10 minutes at 130 ° C. After partial drying, it was further heated and cured at 150 ° C. for 1 hour. A voltage of 10 V was applied between the electrodes in an environment of 80 ° C. and 85% RH, and the insulating properties after being left for 100 hours were evaluated.
◯: Insulation resistance value between lines is 1E + 08Ω or more ×: Insulation resistance value between lines is 1E + 08Ω or less The state when the same sample was floated in a solder bath at 290 ° C. for 30 seconds was observed. The judgment was as follows.
○: No swelling or peeling.
X: Dandruff or peeling occurred.

The results of the above examples are summarized in Table 1.

* Curing agent Ep152: Epicoat 152 (phenol novolac type epoxy)
C-EH: Coronate EH (hexamethylene diisocyanate cyclic trimer)
・ ** Adhesive strength A: Adhesive strength between copper foil and polyimide ・ *** Adhesive strength B: Adhesive strength between polyimide and aluminum plate

As is apparent from the results of the examples, according to the present invention, the adhesiveness to metal and polyimide films, the solder resistance, and the anti-migration property under high temperature and high humidity are particularly useful for circuit boards. An adhesive composition, an adhesive sheet, and a printed circuit board using these can be provided.

According to the present invention, an adhesive composition and an adhesive sheet that are excellent in adhesion to metals and polyimide films, solder resistance, and anti-migration properties under high temperature and high humidity, particularly useful for circuit boards, and The used printed circuit board can be provided.

Claims (8)

A radical polymerizable monomer is graft-polymerized on a polyimide resin in which at least one selected from the group consisting of aliphatic polyester having a carboxyl group or a hydroxyl group at the terminal, butadiene rubber and dimer acid is copolymerized, and the acid value is Polyimide resin which is 30-300 eq / 10 ⁶ g. The polyimide resin according to claim 1, wherein the polyimide resin has an isophorone and / or dicyclohexylmethane residue as an amine component. The polyimide resin according to claim 1 or 2, wherein the polyimide resin has a cyclohexane residue as an acid component. When the total acid component is 100 mol%, a polyimide resin obtained by copolymerizing 0.5 to 20 mol% of a polymerizable unsaturated group-containing dicarboxylic acid and a radical polymerizable monomer, γ-butyrolactone, cyclohexanone, The method for producing a polyimide resin according to any one of claims 1 to 3, wherein the reaction is carried out in one or more solvents selected from the group consisting of cyclopentanone, tetrahydrofuran, ethanol, butanol, toluene and xylene. . The adhesive composition by which 1 or more types chosen from the group of polyfunctional epoxy, a melamine, and an isocyanate compound was mix | blended with the polyimide-type resin in any one of Claims 1-3. An adhesive sheet obtained from the adhesive composition according to claim 5. The printing ink composition which mixed the polyimide resin in any one of Claims 1-3 with 1 or more types chosen from the group of polyfunctional epoxy, a melamine, and an isocyanate compound, and inorganic or organic fine particles. A printed circuit board using the adhesive composition according to claim 5.