JP2957738B2 - Thermosetting resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition which exhibits excellent properties at low temperature curing and is useful for adhesives, laminate materials, molding materials and the like.

[0002]

2. Description of the Related Art A resin composition obtained by adding a polymaleimide to a polyamic acid or a polyimide has been used in various applications because its cured product is tough and has heat resistance. For example, they are used as adhesives and varnishes in the production of printed wiring boards and prepregs. The prepreg is further used for producing a printed wiring board and the like.

[0003] For example, USP 4,362,826 includes:
A thermosetting resin composition containing a polyamic acid obtained from 4,4'-diaminodiphenyl ether and pyromellitic dianhydride and a bismaleimide compound is disclosed. For example, the composition is cast and applied to a substrate such as a copper foil, and then dried by heating to form a cured film (a film supported on the substrate).

However, since the resin composition obtained by adding bismaleimide to polyamic acid as described above uses polyamic acid, it is necessary not only to react the polymaleimide during curing but also to imidize the polyamic acid. is there. For this reason, it is necessary to heat to a temperature of 300 ° C. or more at the time of curing, and it cannot be applied to a substrate weak to heat. In addition, since condensed water is generated with the imidization of the polyamic acid, the generation of voids cannot be ignored even if the amount of water is reduced by the presence of polymaleimide. In particular, when the above composition is interposed between the Kapton film (polyimide film) and a metal foil such as a copper foil to cure the metal foil such as a copper foil, the generation of such voids causes a significant decrease in the adhesive strength. Cause. USP 4,36
It is well known to those skilled in the art that the polyimide obtained by imidizing the amic acid disclosed in US Pat. No. 2,826 is insoluble and infusible in an organic solvent. further,
U.S. Pat. No. 4,362,826 does not specifically illustrate polyimides soluble in organic solvents.

As a composition containing a polyimide and a polymaleimide, for example, a low molecular weight polyimide having amino groups at both terminals obtained by reacting USP 3,842,143 with a tetracarboxylic dianhydride and an excess of diamine can be used. A composition comprising a maleimide is disclosed.
However, when using such a low molecular weight polyimide,
The film obtained from the above composition has no flexibility,
It cannot be a self-supporting film. USP
No. 3,842,143 does not illustrate a composition which is so flexible that a self-supporting film can be obtained and a polyimide therefor.

Further, Japanese Patent Application Laid-Open No. Sho 62-30112 discloses that 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, bis (4- (3-aminophenoxy) phenyl) sulfone and Accordingly, it is disclosed that a composition comprising polyimide and polymaleimide obtained using 2,4-diaminotoluene has good film-forming properties and this film exhibits excellent adhesion. Also,
It is disclosed that this polyimide dissolves in a mixed solvent of toluene and m-cresol. However, Japanese Patent Application Laid-Open No. Sho 62-3
The polyimide disclosed in No. 0112 does not dissolve in organic solvents having a small polarity such as tetrahydrofuran, dioxane, and methylene chloride. The composition is meltable and cures at a relatively low temperature of 250 ° C. to 275 ° C., and exhibits excellent adhesiveness. However, at a cure temperature of 230 ° C. or lower, the properties deteriorate.

As is apparent from the above, a composition containing polyimide and polymaleimide exhibits excellent properties at a sufficiently low curing temperature, and has excellent film-forming properties. Is not conventionally known.

[0008]

SUMMARY OF THE INVENTION The present invention provides a resin composition containing a polyimide and a polymaleimide, which uses a novel polyimide as a specially selected polyimide so that even when the curing temperature is low, it is excellent. It is intended to provide those exhibiting characteristics.

In the thermosetting resin composition of the present invention, the repeating unit is represented by the following general formula (I):

Embedded image [Wherein, in the general formula (I), Ar is a divalent group represented by the general formula (a) of the chemical formula 7 or the general formula (b) of the chemical formula 8,

Embedded image (However, in the general formula (a), the hydrogen of the benzene ring may be substituted with an alkyl group, a halogen, an alkoxy group, or a fluorine-substituted alkyl group, and when there are two or more such substituents, they may be the same or different. May be used).

Embedded image (However, in the general formula (b), A is-(CH ₂ ) m'-,-
C (= O) -, - O -, - S -, - SO 2 -, - C (C
H ₃ ) ₂ — or —C (CF ₃ ) ₂ —, n ′ and m ′ are integers of 1 or more, and hydrogen of the benzene ring is substituted by an alkyl group, a halogen, an alkoxy group, or a fluorine-substituted alkyl group. When there are a plurality of these substituents, they may be the same or different. ) X is -O- or -C
(= O) indicates ^{-O-, R 1, R 2,} R 3 and R ⁴ represents an alkyl group or an alkoxy group having 1 to 4 carbon atoms independently. A polyimide represented by the general formula (VI):

Embedded image [However, in the general formula (VI), R is an integer-valent group having 2 or more carbon atoms, and m is an integer of 2 or more. ] Is contained.

The polyimide is represented by the following chemical formula (II):

Embedded image (Wherein, Z is -C (= O) -, - SO 2 -, -
O -, - S -, - CH 2 -, - CO-NH -, - C (C
H ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —C (＝ O) —O— or a bond; n represents an integer of 1 to 4; at best, the hydrogen of each benzene ring may include a structural unit (B) represented by may be substitution) with a substituent. As the above substituent,
Alkyl group, an alkoxy group, a halogen.

The polyimide preferably contains the structural unit (B) in an amount of 90 mol% or less in the polyimide. The polyimide of the present invention more preferably contains the structural unit (A) / the structural unit (B) so as to be 90/10 to 10/90, particularly preferably 90/20 to 40/60. When the structural unit (B) is used, the softening point of the polyimide can be further lowered, and the flexibility can be improved.

The polyimide is represented by the general formula (II)
I))

Embedded image (Where Ar is a divalent aromatic group, and X is -C (=
O)-or -CO-)), and an acid dianhydride represented by the general formula (IV):

Embedded image (Wherein, Y represents an amino group or an isocyanate group, and R ¹ , R ² , R ³ and R ⁴ each independently represent an alkyl group or an alkoxy group having 1 to 4 carbon atoms). It can be produced by reacting a compound.

First, the acid dianhydride represented by the general formula (III) will be described in detail.

In the general formula (III), Ar is a divalent group of a group (a) represented by the following formula (9) and a group (b) represented by the following formula (10).

Embedded image (However, in the formula, hydrogen of the benzene ring is a lower alkyl group such as a methyl group, an ethyl group and a propyl group, chlorine, bromine, and fluorine .
Halogen, methoxy group, an alkoxy group of ethoxy groups,
It may be substituted with a fluorine-substituted alkyl group such as a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, or a perfluorooctyl group. May be the same or different).

Embedded image (Where Z is (CH ₃ ) m ', -C (= O)
—, —O—, —S—, —SO ₂ —, —C (CH ₃ ) ₂ — or —C (CF ₃ ) ₂ —, n ′ and m ′ are integers of 1 or more, and hydrogen on the benzene ring methyl group, ethyl group, lower alkyl group isopropyl group, chlorine, bromine, halogen <br/> emissions of fluorine, an alkoxy group such as methoxy group and ethoxy group, a trifluoromethyl group, pentafluoroethyl group, perfluoro It may be substituted with a fluorine-substituted alkyl group such as a butyl group, a perfluorohexyl group, or a perfluorooctyl group, and when there are a plurality of these substituents, these may be the same or different.)

Specific examples of the acid dianhydride represented by the general formula (III) include catechol bistrimellitate dianhydride, resorcinol bistrimellitate dianhydride, dihydroxybenzene bistrimellitate dianhydride, and bisphenol A bistrimellitate. Tate dianhydride, tetrachlorobisphenol A bistrimellitate dianhydride, tetrabromobisphenol A bistrimellitate dianhydride,
Biphenyl bistrimellitate dianhydride,
The acid dianhydride represented by [General formula (A)] etc. are mentioned.

Embedded image (Where X represents -O- or -C (= O) -O-, and two Xs may be the same or different; R represents an alkyl group or a fluoroalkyl group; R may be the same or different).

Examples of the acid dianhydride represented by the general formula (A) include those shown below.

Embedded image

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Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

In the thermosetting resin composition of the present invention , a polyimide of an acid dianhydride other than the above-mentioned acid dianhydride may be used in combination as long as the object of the present invention is not impaired. Such acid dianhydrides include 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4 '-
[2,2,2-trifluoro-1- (trifluoromethyl) ethylidene] bis (1,2-benzenedicarboxylic anhydride) and the like. These polyimides are, at most ports
It is used in an amount of 50 mol% or less, more preferably 30 mol% or less, based on the total amount of the imide .

Among the compounds represented by the general formula (IV), those in which Y is an amino group include 4,4'-diamino-3,3 ', 5,5'-tetramethyldiphenylmethane, , 4'-Diamino-3,3 ', 5,5'-tetraethyldiphenylmethane, 4,4'-diamino-
3,3 ′, 5,5′-tetra-n-propyldiphenylmethane, 4,4′-diamino-3,3 ′, 5,5′-tetraisopropyldiphenylmethane, 4,4′-diamino-3,3 ′, 5 , 5'-Tetrabutyldiphenylmethane, 4,4'-diamino-3,3'-dimethyl-5,
5′-diethyldiphenylmethane, 4,4′-diamino-3,3′-dimethyl-5,5′-diisopropyldiphenylmethane, 4,4′-diamino-3,3′-diethyl-5,5′-diisopropyldiphenylmethane, 4,
4'-diamino-3,5-dimethyl-3 ', 5'-diethyldiphenylmethane, 4,4'-diamino-3,5-
Dimethyl-3 ', 5'-diisopropyldiphenylmethane, 4,4'-diamino-3,5-diethyl-3',
5'-diisopropyldiphenylmethane, 4,4'-diamino-3,5-diethyl-3 ', 5'-dibutyldiphenylmethane, 4,4'-diamino-3,5-diisopropyl-3', 5'-dibutyldiphenylmethane, 4,
4'-diamino-3,3'-diisopropyl-5,5 '
-Dibutyldiphenylmethane, 4,4'-diamino-
3,3′-dimethyl-5,5′-dibutyldiphenylmethane, 4,4′-diamino-3,3′-diethyl-5,
5'-dibutyldiphenylmethane and the like.

Among the compounds represented by the above general formula (IV), those in which Y is an isocyanate group include those obtained by replacing "amino" with "isocyanate" in the diamines exemplified above. be able to.

In the present invention, the reaction partner of the acid dianhydride is a compound other than the compound represented by the general formula (IV).
4 [General formula (V)]

Embedded image (Wherein, Z is -C (= O) -, - SO 2 -, -
O -, - S -, - CH 2 -, - CO-NH -, - C (C
H ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —C (＝ O) —O— or a bond, Y represents an amino group or an isocyanate group, n represents an integer of 1 to 4, A plurality of Zs may be the same or different, and the hydrogen of each benzene ring may be substituted with an alkyl group, an alkoxy group, or a halogen).

As the compound represented by the general formula (V), in the general formula (V), in a combination of one Z and one Y and a combination of two Zs, each is para-positioned to the same benzene ring. Alternatively, those bonded to the meta position are preferred.

Among the compounds represented by the general formula (V),
Examples of the diamine in which group Y is an amino group include bis (anilinoisopropylidene) benzene, bis (aminophenoxy) benzene, bis (aminophenoxyphenyl) propane, bis (aminophenoxyphenyl) sulfone, and bis (aminophenoxyphenyl) ketone , Bis (aminophenoxyphenyl) hexafluoropropane, 4,
4'-bis [3- (4-amino-α, α'-dimethylbenzyl) phenoxy] diphenylsulfone, 4,4'-
Bis [3- (4-amino-α, α′-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4
-(4-amino-α, α'-dimethylbenzyl) phenoxy] diphenylsulfone, 4,4'-bis [4- (4
-Amino-α, α'-dimethylbenzyl) phenoxy]
Benzophenone, 4- [3- (4-amino-α, α'-
Dimethylbenzyl) phenoxy] -4 '-[4- (4-
Amino-α, α'-dimethylbenzyl) phenoxy] diphenylsulfone, 4- [3- (4-amino-α, α '
-Dimethylbenzyl) phenoxy] -4 '-[4-amino-α, α'-dimethylbenzyl) phenoxy] benzophenone, 4,4'-bis [3- (3-amino-α,
α'-dimethylbenzyl) phenoxy] diphenylsulfone, 4,4'-bis [3- (3-amino-α, α'-
Dimethylbenzyl) phenoxy] benzophenone, 4,
4'-bis [2- (4-amino-α, α'-dimethylbenzyl) phenoxy] diphenylsulfone, 4,4'-
Bis [2- (4-amino-α, α′-dimethylbenzyl) phenoxy] benzophenone, 3,3′-bis [3
-(4-amino-α, α'-dimethylbenzyl) phenoxy] diphenylsulfone, 3,3'-bis [3- (4
-Amino-α, α'-dimethylbenzyl) phenoxy]
Benzophenone and the like may be mentioned, and these may be used as a mixture.

Among the compounds represented by the general formula (V),
Examples of the diisocyanate in which the group Y is an isocyanate group include 4,4′-bis [3- (4-isocyanate-α,
α′-dimethylbenzyl) phenoxy] diphenyl ketone, 4,4′-bis [3- (4-isocyanato-α,
α'-dimethylbenzyl) phenoxy] diphenylsulfone and the like, and among the compounds represented by the general formula (V), diamines in which the group Y is an amino group include:
Some amino groups are replaced with isocyanate groups.

The compound represented by the general formula (IV) and the compound represented by the general formula (V) have a former / latter molar ratio of 1
It is preferable to use it so as to be 0/90 to 90/10. If the ratio is too small, the solubility in a solvent having a small polarity tends to decrease. If the ratio is too large, the formula (V)
By using the compound represented by the formula, the effect of lowering the softening point of the polyimide is reduced. The above ratio is
It is particularly preferred that the ratio be from 40/60 to 90/10. In this case, especially dioxane, diglyme, monoglyme,
It is preferable in terms of solubility in toluene and the like.

When a diamine is used as a reaction partner of the acid dianhydride, other diamines which may be used in combination with the above-mentioned diamines include diaminodiphenylmethane, diaminodiphenylether, diaminodiphenylsulfone,
There are diaminodiphenyl ketone, diaminodiphenylpropane, phenylenediamine, toluenediamine, diaminodiphenylsulfide, diaminodiphenylhexafluoropropane, diaminodialkyldiphenylmethane, and the like. Two or more of these may be used in combination. Used within a range that does not impair the object of the present invention.

When a diisocyanate is used as a reaction partner of the acid dianhydride, the diisocyanate which may be used in combination with the above-mentioned diisocyanate is diphenylmethane diisocyanate or toluene. There is a diamine in which the amino group of the above-mentioned other diamines such as range isocyanate is replaced with an isocyanate group. Any of the above diisocyanates can be produced by reacting the above diamine with phosgene in a conventional manner.

In the present invention, the polyimide can be produced as follows. When a diamine is used as a reaction partner of the acid dianhydride, the acid dianhydride and the diamine are mixed in an organic solvent, if necessary, in the presence of a catalyst such as tributylamine, triethylamine, and triphenyl phosphite.
A method of directly obtaining a polyimide by heating to 100 ° C. or higher, preferably 180 ° C. or higher to perform imidization (catalyst is preferably used in an amount of 0 to 15% by weight based on the total amount of the reaction components, particularly 0.01 to 15% by weight), a dianhydride and a diamine are reacted in an organic solvent at less than 100 ° C. to produce a varnish of a polyamic acid, which is a precursor of a polyimide, and thereafter, The varnish is heated to be imidized, or a ring closing agent such as an acid anhydride such as acetic anhydride, propionic anhydride, and benzoic anhydride; a carbodiimide compound such as dicyclohexylcarbodiimide;
If necessary, a ring-closing catalyst such as pyridine, isoquinoline, trimethylamine, aminopyridine, imidazole or the like is added to chemically ring-close (imidize) (the ring-closing agent and the ring-closing catalyst are each 1 to 1 mol based on the acid anhydride). It is preferable to use within a range of 8 mol).

Examples of the organic solvent include N-methyl-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, sulfolane, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidone and the like. And phenolic solvents such as phenol, cresol, xylenol, and p-chlorophenol.

Further, benzene, toluene,
Xylene, methyl ethyl ketone, acetone, tetrahydrofuran, dioxane, monoglyme, diglyme, methyl cellosolve, cellosolve acetate, methanol,
Among ethanol, isopropanol, methylene chloride, chloroform, tricrene, tetrachloroethane, etc., those which dissolve the raw material monomer and the polyimide or polyamic acid may be used, and those which do not dissolve these may be used within a range that does not impair the solubility. It can be used by mixing with other solvents.

In the production of the above-mentioned polyimide and polyamic acid as a precursor thereof, solid-state reaction,
A melting reaction at a temperature of 00 ° C. or lower can be used.

When diisocyanate is used as a reaction partner of the acid dianhydride, the reaction can be carried out according to the above-mentioned method for directly obtaining a polyimide. However, it is sufficient that the reaction temperature is at least room temperature, especially at least 60 ° C.

In the present invention, the acid dianhydride and its reaction partner are preferably used in approximately equimolar amounts, but an excess amount of any one is allowed to be 10 mol%, particularly preferably up to 5 mol%. .

In the present invention, the acid dianhydride represented by the general formula (III) and the reaction partner of the general formula (IV)
By using the compound represented by the formula, a polyimide having a low softening point and soluble in a low boiling point solvent can be obtained. From the conventional knowledge, if the acid dianhydride represented by the general formula (III) is used, it cannot be said that the resulting polyimide has a low softening point or is soluble in a low-boiling solvent. If the compound represented by (IV) is used, it cannot be said that the resulting polyimide is soluble in a solvent having a low softening point or a low boiling point, so the polyimide in the present invention exhibits the above-described properties. It is believed that this is a remarkable property due to the combination of these compounds. Further, when the compound represented by the general formula (V) is combined with the compound represented by the general formula (III) and the compound represented by the general formula (IV) as a reaction partner of the acid dianhydride, the obtained compound is obtained. Not only can the softening point of polyimide be lowered further,
It is preferable to further improve the solubility in a low-polarity solvent having a small polarity. Further, it is preferable to use a compound represented by the general formula (V) in combination, since the polyimide is given flexibility. That the polyimide is dissolved in the low-boiling solvent means that, compared to dimethylformamide, N-methylpyrrolidone, etc., not only is the workability improved when using a varnish obtained by dissolving the polyimide or polyimide and polymaleimide, Coating from the varnish, coating by casting, etc.,
This is preferable because the film can be dried at a lower temperature when producing a film or the like.

[0034] The above Porimareimi soil N, N '- (4,
4'-diphenylmethane) bismaleimide, N, N'-
(4,4'-diphenyloxy) bismaleimide, N,
N'-p-phenylenebismaleimide, N, N'-m-
Phenylenebismaleimide, N, N'-2,4-tolylenebismaleimide, N, N'-2,6-tolylenebismaleimide, N, N'-ethylenebismaleimide,
N '-[4,4'-[2,2'-bis (4,4'-phenoxyphenyl) isopropylidene]] bismaleimide, N, N'-hexamethylenebismaleimide, in a compound represented by, it is used as a mixture singly or two or more kinds.

Embedded image (Hereinafter, abbreviated as BMIM),

Embedded image

Embedded image (Hereinafter, this is abbreviated as ATUBMI),

Embedded image

Embedded image

Embedded image (Where r represents an integer)

The mixing ratio of the polyimide and the polymaleimide is appropriately determined according to the purpose, but it is preferable to use the polymaleimide in an amount of 5 to 180 parts by weight based on 100 parts by weight of the polyimide. If the amount of the polymaleimide is too small, the curing is not sufficient, and if it is too large, the resin composition becomes brittle. Particularly in the case of producing a self-supporting film, it is particularly preferable to use the polymaleimide in a proportion of 100 parts by weight or less with respect to 100 parts by weight of the polyimide in terms of maintaining sufficient flexibility.

The resin composition of the present invention can be cured at a temperature lower than 275 ° C. (further, a temperature lower than 230 ° C.) to obtain a cured product having excellent heat resistance and the like.
In order to cure at lower temperature, organic compounds such as t-butyl perbenzoate, t-butyl hydroperoxide, benzoyl peroxide, and 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 are used. It is preferable to add a radical polymerization initiator such as a peroxide. In particular, the curing reaction can be caused, for example, at about 200 ° C. The radical polymerization initiator is preferably used in an amount of 0.1 to 10% by weight based on the total amount of polyimide and polymaleimide.

The resin composition according to the present invention comprises a polyimide
(A) and polymaleimide (B) Further, if necessary, a mixture in which a radical polymerization initiator is mixed in a powder form may be used, or a mixture in which these are dissolved in an organic solvent (varnish) may be used.
Organic solvents that can be used at this time include non-aqueous polar solvents such as N, N-dimethylformamide and N-methylpyrrolidone, ether solvents such as dioxane, tetrahydrofuran, diglyme and monoglyme, and chlorine solvents such as methylene chloride. There are low-boiling solvents such as aromatic solvents such as toluene and organic solvents having a small polarity.

The resin composition of the present invention comprises a glass plate,
After casting and drying on a stainless steel plate or the like, it can be cured by heating to form a cured film. This film is useful as an insulating film, a base film for a laminated board, and the like.

The resin composition of the present invention can be used as an adhesive itself. This adhesive may be used in the form of a varnish. The varnish is cast on a glass plate, a stainless steel plate, etc., dried, and then peeled off, containing no base material, having high flexibility and being uncured. Agent (self-supporting film adhesive) before use.
Such adhesives can be used for various applications, but a metal-clad laminate is obtained by laminating a metal plate such as an aluminum plate, a core material such as a plastic film such as a polyimide film and a metal foil such as a copper foil or an aluminum foil. It is particularly useful as an adhesive for the production of The adhesive exhibits excellent adhesion at relatively low heat (at the curing temperature).

The varnish-like resin composition of the present invention comprises:
Further, it can be used as a prepreg by impregnating and drying a substrate such as glass cloth and carbon cloth.

In the production of the above film adhesive and prepreg, the drying temperature and time vary depending on the type of solvent and polymaleimide used. The temperature must be kept lower than the temperature at which polymerization of the polymaleimide becomes remarkable, but the resin composition of the present invention can be dissolved in a low-boiling solvent or an organic solvent having a small polarity and easy to volatilize. Can be dried. At this time, even if a radical initiator is present, polymerization can be suppressed and drying can be easily performed. Preferably, the time is such that the amount of residual solvent is 5% by weight or less.

Further, the resin composition according to the present invention can be used as a molding material in powder form. The curing temperature varies depending on the type of the polymaleimide, but by heating and curing these, a tough heat-resistant molded article can be obtained.

[0043]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these ranges.

First, a synthesis example of the polyimide used in the present invention will be described.

Synthesis Example 1 A four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube and a calcium chloride tube was charged with 4,4'-diamino-3,
2.745 g (7.5 mmol) of 3 ', 5,5'-tetraisopropyldiphenylmethane (IPDDM) and 2,2-bis [4- (4-aminophenoxy) phenylpropane]
(BAPP) 1.025 g (2.5 mmol) and N, N-
28.6 g of dimethylformamide (DMF) was added and dissolved. Next, bisphenol A bistrimellitate dianhydride (BABT) while cooling so as not to exceed 5 ° C.
5.76 g (10.0 mmol) are added in small portions, followed by cooling for 1 hour without exceeding 5 ° C. and then 6 hours at room temperature.
The reaction was allowed to proceed for a period of time to synthesize a polyamic acid. 2.55 g of acetic anhydride and 1.98 g of pyridine were added to the obtained varnish of polyamic acid, and reacted at room temperature for 3 hours to synthesize a polyimide. The resulting polyimide varnish was poured into water, and the resulting precipitate was separated, crushed and dried to obtain a polyimide powder.

This polyimide powder was added to DMF at 0.1 g / dl.
And the reduced viscosity measured at 30 ° C. was 1.35 dl / g. FIG. 1 shows an infrared absorption spectrum of this polyimide.

A solubility test was conducted by adding the polyimide powder to various organic solvents to a concentration of 5% by weight and observing the dissolution state at room temperature. As a result, the polyimide powder contained DMF, N-methylpyrrolidone (NMP), dioxane, tetrahydrofuran (TH
F), soluble in methylene chloride, diglyme, monoglyme, and toluene.

Further, this polyimide powder was dissolved in DMF. After casting the obtained varnish on a glass plate, 8
After drying at 0 ° C. for 10 minutes, peel off and fix on an iron frame for 15 minutes.
After drying at 0 ° C. for 1 hour, a film was obtained.

The polyimide powder was dissolved in toluene. After casting the obtained varnish on a glass plate,
After drying for 10 minutes at 150 ° C
For 30 minutes to obtain a film.

Using the thus obtained film, the softening point of the polyimide was measured by the penetration method under the conditions of a load of 25 kg / cm ² and a temperature rising rate of 10 ° C./min.
As a result, in each case, the softening point of polyimide was 2
It was 60 ° C. In addition, any of the obtained films was 1
When the film was bent at an angle of 80 degrees and subjected to a flexibility test, the film showed good flexibility without cracking.

The polyimide obtained in this synthesis example has a composition unit α of 75 mol% represented by the following formula
The composition unit contains 25 mol% of the structural unit represented by formula (2). Structural unit α:

Embedded image Structural unit β:

Embedded image

Synthesis Example 2 Instead of 2.745 g of IPDDM and 1.025 g of BAPP, 1.83 g (5.0 mmol) of IPDDM and 2.16 g (5.0 mmol) of bis [4- (3-aminophenoxy) phenyl] sulfone (m-APPS) A polyimide powder was obtained in the same manner as in Synthesis Example 1 except for using, and the measurement of reduced viscosity and the solubility test were performed in the same manner as in Synthesis Example 1 using this polyimide powder. FIG. 2 shows an infrared absorption spectrum of this polyimide. As a result, the obtained polyimide powder has a reduced viscosity of 1.02 dl / g, and DMF, NM
It was soluble in P, dioxane, methylene chloride and diglyme. Further, a film was prepared according to the case where DMF of Synthesis Example 1 was used. Further, a film was prepared in the same manner except that DMF was replaced with dioxane. Using these films, the softening point of the polyimide was measured and a flexibility test was conducted in accordance with Synthesis Example 1. Each of the polyimides had a softening point of 245 ° C., and all of the obtained films were excellent in flexibility.

The polyimide obtained in this synthesis example contains 50 mol% of the structural unit α and 50 mol% of the structural unit γ represented by the following formula. Structural unit γ:

Embedded image

Synthesis Example 3 The amount of IPDDM used was 3.66 g (10.0 mmol).
A polyimide powder was obtained according to Synthesis Example 1 except that BAPP was not used.
The measurement of the reduced viscosity and the solubility test were performed in accordance with As a result, the obtained polyimide powder had a reduced viscosity of 0.35 dl /
g, softening point 275 ° C, DMF, NMP, T
It was soluble in HF, dioxane, methylene chloride, diglyme and toluene. FIG. 3 shows an infrared absorption spectrum of this polyimide. Furthermore, a film was prepared according to the case of using DMF of Synthesis Example 1, and the measurement of the softening point and the flexibility test of polyimide were performed. The softening point of the polyimide was 275 ° C., and the film was broken as a result of the flexibility test and was brittle. The polyimide obtained in this synthesis example contains 100 mol% of the structural unit α.

Example 1 100 g of the polyimide powder obtained in Synthesis Example 1 and 2,2-
50 g of bis [4- (4-maleimidophenoxy) phenyl] propane (BBMI) is dissolved in 400 g of N, N-dimethylformamide (DMF), and 3 g of t-butylperoxybenzoate is added to the resin composition (varnish).
I got This resin composition was cast on a glass plate,
, And then peeled off to obtain a film. This film was fixed on an iron frame and heated at 150 ° C. for 1 hour to obtain a well-dried uncured film adhesive. This film adhesive had a thickness of 25 μm and a softening point of 167 ° C., and showed excellent flexibility without breaking even when bent at an angle of 180 °.

When this film adhesive was completely cured by heating at 200 ° C. for 2 hours, the resulting cured film had a glass transition point of 202 ° C. and an elongation of 7.6%.

The above film-like adhesive was pressed between a polyimide film having a thickness of 50 μm and a roughened copper foil having a thickness of 35 μm on one side at 30 kg / cm ² , at 200 ° C. for 2 hours, to form a flexible printed wiring board. A substrate was obtained. 9 of this board
The 0 degree copper foil peeling strength is 1.3 kgf / c at room temperature.
m, 1.2Kgf / cm in 200 ° C atmosphere (in each case,
(Measured at a tensile speed of 50 mm / min). Even when this substrate was immersed in a 300 ° C. solder bath for 60 seconds, no blistering or peeling occurred.

Example 2 Bismaleimide ATU exemplified above instead of BBMI
A film adhesive was obtained in the same manner as in Example 1 except that 30 g of BMI was added. The resulting film adhesive has a thickness of 2
It had a softening point of 5 [mu] m and a softening point of 172 [deg.] C.

When this film adhesive was completely cured by heating at 200 ° C. for 1 hour, the cured film obtained had a glass transition point of 207 ° C. and an elongation of 11.0%.

A substrate for a flexible printed wiring board was obtained according to Example 9 using the above film-like adhesive (however,
Press time is one hour). The 90 ° copper foil peeling strength of this substrate was 1.1 kgf / cm at room temperature and 1.1 kgf / cm at 200 ° C. (in each case, the pulling speed was 50 kgf / cm).
mm / min). Even when this substrate was immersed in a 300 ° C. solder bath for 60 seconds, no blistering or peeling occurred.

Example 3 A film adhesive was obtained in the same manner as in Example 2 except that the amount of ATUBMI used was changed to 50 g. The resulting film adhesive had a thickness of 25 μm, a softening point of 147 ° C., and was excellent in flexibility without breaking even when bent at 180 °.

A substrate for a flexible printed wiring board was obtained according to Application Example 1 by using the above film adhesive. The 90 degree copper foil peeling strength of this substrate is 0.9 kg at room temperature.
f / cm, 0.9 kgf / cm in an atmosphere of 200 ° C. (in each case, measured at a pulling speed of 50 mm / min). Even when this substrate was immersed in a 300 ° C. solder bath for 60 seconds, no blistering or peeling occurred.

Example 4 A film adhesive was obtained in the same manner as in Example 2 except that 10 g of ATUBMI was added. The obtained film adhesive had a thickness of 25 μm and a softening point of 195 ° C.
It was excellent in flexibility without breaking even when bent at 0 degrees.

When the film adhesive was completely cured by heating at 200 ° C. for 1 hour, the resulting cured film had a glass transition point of 220 ° C. and an elongation of 16%.

A substrate for a flexible printed wiring board was obtained in the same manner as in Example 1 by using the above film-like adhesive (however,
Press time is one hour). The 90 ° copper foil peeling strength of this substrate was 1.1 kgf / cm at room temperature and 1.0 kgf / cm at 200 ° C. (in each case, the pulling speed was 50 mm.
/ Min). Also, this substrate is
Even when immersed in a solder bath at 0 ° C. for 60 seconds, blistering and peeling did not occur.

Example 5 100 g of the polyimide powder obtained in Synthesis Example 1 and ATUB
50 g of MI was dissolved in a mixed solvent of 300 g of toluene and 100 g of DMF, and 2,5-dimethyl-2,5-di (t-
3 g of (butylperoxy) hexyne-3 was added to obtain a resin composition (varnish). This resin composition was cast on a glass plate, dried at 80 ° C. for 10 minutes, and then peeled off to obtain a film. After fixing this film on an iron frame,
By heating at 30 ° C. for 30 minutes, a well-dried uncured film adhesive was obtained. This film adhesive had a thickness of 25 μm and a softening point of 175 ° C., and exhibited excellent flexibility without breaking even when bent at an angle of 180 °.

When this film adhesive was completely cured by heating at 200 ° C. for 1 hour, the resulting cured film had a glass transition point of 215 ° C. and an elongation of 10.4%.

A substrate for a flexible printed wiring board was obtained in the same manner as in Example 1 using the above film-like adhesive (however,
Press time is one hour). The 90 ° copper foil peeling strength of this substrate was 1.2 kgf / cm in a room temperature atmosphere and 1.1 kgf / cm in a 200 ° C. atmosphere (in each case, the pulling speed was 50 mm
/ Min). Also, this substrate is
Even when immersed in a solder bath at 0 ° C. for 300 seconds, blistering and peeling did not occur.

Example 6 In Example 5, 2,5-dimethyl-2,5-di (t
An uncured film adhesive was obtained according to Example 5, except that 3 g of (-butylperoxy) hexyne-3 was not used. This film adhesive has a thickness of 25 μm and a softening point of 1
It was 75 ° C., and showed excellent flexibility without cracking even when bent at an angle of 180 °.

When this film adhesive was completely cured by heating at 230 ° C. for 5 hours, the cured film obtained had a glass transition point of 210 ° C.

A substrate for a flexible printed wiring board was obtained according to Example 1 using the above film-like adhesive (however,
(Press temperature 230 ° C, press time 5 hours). The 90 degree copper foil peeling strength of this substrate is 1.0 kg at room temperature.
f / cm (measured at a pulling speed of 50 mm / min). Even when this substrate was immersed in a 300 ° C. solder bath for 60 seconds, no blistering or peeling occurred.

Example 7 Bismaleimide BMI exemplified above instead of BBMI
A film-like adhesive was obtained according to Example 1, except that 30 g of M was added. The resulting film adhesive has a thickness of 25μ.
m, the softening point was 195 ° C, and it was excellent in flexibility without cracking even when bent at 180 °.

When this film adhesive was completely cured by heating at 200 ° C. for 1 hour, the resulting cured film had a glass transition point of 205 ° C. and an elongation of 9.4%.

A substrate for a flexible printed wiring board was obtained according to Example 1 using the above film-like adhesive (however,
Press time is one hour). The 90 ° copper foil peeling strength of this substrate was 0.9 kgf / cm in a room temperature atmosphere and 0.9 kgf / cm in a 200 ° C. atmosphere (in each case, the tensile speed was 50 kgf / cm).
mm / min). Even when this substrate was immersed in a 300 ° C. solder bath for 60 seconds, no blistering or peeling occurred.

Example 8 100 g of the polyimide powder obtained in Synthesis Example 2 and BBMI
Using 30 g, a film adhesive was obtained according to Example 1. The obtained film adhesive had a thickness of 25 μm and a softening point of 195 ° C., and was excellent in flexibility without breaking even when bent at 180 °.

A substrate for a flexible printed wiring board was obtained according to Example 1 using the above film-like adhesive (however,
Press time is one hour). The 90 degree copper foil peeling strength of this substrate is 0.9 kgf / cm at room temperature atmosphere (tensile speed 50
mm / min).

Example 9 A film-like adhesive was obtained according to Example 8, except that the amount of BBMI used was changed to 50 g. The resulting film adhesive had a thickness of 25 μm, a softening point of 182 ° C., and was excellent in flexibility without breaking even when bent at 180 °.

A substrate for a flexible printed wiring board was obtained according to Example 1 using the above film-like adhesive (however,
Press time is one hour). The 90 degree copper foil peeling strength of this substrate is 1.0 kgf / cm at room temperature atmosphere (tensile speed 5
(Measured at 0 mm / min).

Example 10 100 g of the polyimide powder obtained in Synthesis Example 3 and N, N '
Dissolve 50 g of-(diphenylmethane) bismaleimide in a mixed solvent of 200 g of toluene and 200 g of DMF,
3 g of 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 was added to the resin composition (varnish).
I got This resin composition is impregnated in a glass cloth having a thickness of 100 μm, and is impregnated at 80 ° C. for 30 minutes and then at 150 ° C. for 3 minutes.
The resultant was dried by heating for 0 minutes to obtain a prepreg.

Five prepregs were stacked, and this was further sandwiched between 35 μm thick single-sided roughened copper foils at 50 kg / c.
Pressing was performed under the conditions of m ² , 230 ° C. and 1 hour to obtain a copper-clad laminate. The 90 degree copper foil peeling strength of this laminate was 0.9 kgf / cm (measured at a pulling speed of 50 mm / min) in a room temperature atmosphere. Even when this substrate was immersed in a 300 ° C. solder bath for 60 seconds, no blistering or peeling occurred. The glass transition point measured after peeling off the copper foil of the laminate was 245 ° C.

Comparative Example 1 In a four-necked flask equipped with a stirrer, thermometer, nitrogen gas inlet tube and calcium chloride tube, 2.16 g (5.0 mmol) of m-APPS, 0.61 g (5.0 mmol) of metatoluylenediamine and 24.0 g of DMF was added and dissolved. next,
BTDA (3.22 g, 10.0 mmol) was added little by little under ice-cooling, and the mixture was reacted for 5 hours while cooling so as not to exceed 5 ° C. to synthesize a polyamic acid. 2.55 g of acetic anhydride and 1.98 of pyridine were added to the obtained varnish of polyamic acid.
g was added and reacted at room temperature for 3 hours to synthesize a polyimide. The resulting polyimide varnish was poured into water, and the resulting precipitate was separated, crushed and dried to obtain a polyimide powder.

Using this polyimide powder, the measurement of reduced viscosity and the solubility test were carried out in accordance with Synthesis Example 1. As a result, the obtained polyimide powder had a reduced viscosity of 0.72 dl /
g, soluble in DMF, but dioxane, T
It was insoluble in HF, diglyme, monoglyme, and toluene.

100 g of this polyimide powder and BMI10
g in 400 g of DMF to obtain a resin composition (varnish)
I got This resin composition was cast on a glass plate,
After drying at 10 ° C. for 10 minutes, the film was peeled off to obtain a film.
This film was fixed to an iron frame and heated at 150 ° C. for 30 minutes and at 180 ° C. for 30 minutes to obtain a well-dried uncured film adhesive. This film adhesive had a softening point of 230 ° C. and exhibited excellent flexibility without breaking even when bent at an angle of 180 °.

The above film-like adhesive was pressed between one-side roughened copper foil having a thickness of 35 μm and 30 kg / cm ² at 200 ° C. for 1 hour, but no adhesion was obtained. 3 g of 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 was dissolved in the above resin composition to prepare a film-like adhesive in the same manner as described above, and this was coated on one side with a thickness of 35 μm. Although pressed between the roughened copper foils under the conditions of 30 kg / cm ² , 200 ° C. and 1 hour, no adhesion was possible.

[0084]

The thermosetting resin compositions according to the first to third aspects have excellent properties such as adhesiveness and heat resistance when cured at a low temperature.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of a polyimide obtained in Synthesis Example 1.

FIG. 2 is an infrared absorption spectrum of a polyimide obtained in Synthesis Example 2.

FIG. 3 is an infrared absorption spectrum of a polyimide obtained in Synthesis Example 3.

Claims (3)

(57) [Claims] (1) a repeating unit represented by the general formula (I): [Wherein, in the general formula (I), Ar is a divalent group represented by the general formula (a) of the chemical formula 2 or the general formula (b) of the chemical formula 3, (However, in the general formula (a), the hydrogen of the benzene ring may be substituted with an alkyl group, a halogen, an alkoxy group, or a fluorine-substituted alkyl group. When two or more such substituents are present, they may be the same or different. May be used). Embedded image (However, in the general formula (b), A is-(CH ₂ ) m'-,-
C (= O) -, - O -, - S -, - SO 2 -, - C (C
H ₃ ) ₂ — or —C (CF ₃ ) ₂ —, n ′ and m ′ are integers of 1 or more, and hydrogen of the benzene ring is substituted with an alkyl group, a halogen, an alkoxy group, or a fluorine-substituted alkyl group. When there are a plurality of these substituents, they may be the same or different. ) X is -O- or -C
(= O) -O-, wherein R ¹ , R ² , R ³ and R ⁴ each independently have 1 to 4 carbon atoms
Represents an alkyl group or an alkoxy group. And a polyimide represented by the general formula (VI): [However, in the general formula (VI), R is an integer-valent group having 2 or more carbon atoms, and m is an integer of 2 or more. ] The thermosetting resin composition containing the polymaleimide represented by these. 2. A repeating unit represented by the general formula (I):
Consisting of [general formula (II)], wherein
A thermosetting resin composition comprising 10/90 mol% of a polyimide and the polymaleimide according to claim 1. Embedded image [However, in the general formula (II), Ar, X are as defined in general formula (I), Z -C (= O) -, - SO 2 -, - O -, - S -, -
CH ₂ —, —CO—NH—, —C (CH ₃ ) ₂ —, —C (CF ₃ )
_{2 represents-} , -C (= O) -O- or a bond, n represents an integer of 1 to 4, a plurality of Zs may be the same or different, and hydrogen of each benzene ring is an alkyl group, It may be substituted with an alkoxy group or halogen. ] 3. The thermosetting resin composition according to claim 1, further comprising a radical polymerization initiator.