JP2008101124A - Method for producing polyimide resin and polyimide resin varnish - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyimide resin satisfying catalytic activity, heat-resistance, electrical insulation, colorless transparency, resin stability, etc., at the same time and having excellent characteristics and a polyimide resin varnish obtained by the production method. <P>SOLUTION: The method for producing a polyimide resin comprises the reaction of (a) a trivalent and/or tetravalent polycarboxylic acid derivative having an acid anhydride group with (b) a polyisocyanate in an organic solvent by using a polymerization catalyst comprising an aluminum complex selected from a compound expressed by general formula (1), a compound expressed by general formula (2) and a compound expressed by general formula (3). The invention further provides a polyimide resin varnish obtained by the production method. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a polyimide-based resin having excellent heat resistance, mechanical strength, electrical characteristics, and chemical resistance, and particularly used in the electric and electronic fields, and a polyimide-based resin varnish to be obtained.

  Polyimide resins have been widely used as industrial materials in the fields of electricity, electronics, machinery, aviation and the like because of their excellent heat resistance, mechanical strength, electrical characteristics, chemical resistance, and the like. In particular, types that are soluble in organic solvents include coating materials such as enamel varnish, coating materials for electrical insulation (overcoat inks for semiconductor elements and various electronic components, solder resist inks, interlayer insulation films, etc.), It is preferably used in applications where solution molding is essential, such as adhesives.

  In general, a polyimide resin is a method of producing an acid anhydride group-containing polycarboxylic acid component and an isocyanate component (isocyanate method), or after reacting an acid anhydride group-containing polycarboxylic acid component with an amine to form an amic acid. , And a known method such as a ring closure method (direct method). Industrially, the isocyanate method is advantageous. The isocyanate method is carried out by heat condensation in the presence of a polar organic solvent while removing the liberated carbon dioxide gas from the reaction system. In order to accelerate the reaction, catalysts such as amines, alkali metal alkoxides, alkali metal halides, and alkaline earth metal compounds may be added.

  For example, Patent Documents 1 and 2 use compounds containing alkali metal and halogen in the molecule such as potassium fluoride and sodium methylate. However, it is considered that such a catalytic action by the alkali metal compound is caused by an ionic reaction, and there is a problem that the ionic catalyst after the reaction remains in the resin and greatly reduces the electrical insulating property of the resin. Further, it is recognized that the resin varnish has a haze caused by the catalyst or the resin is considered to be decomposed during the long-term storage.

For example, Patent Documents 3 and 4 use tertiary amines such as DBU (1,8-diazabicyclo [5.4.0] -7-undecene). Resins using such amines have relatively good electrical insulation. However, such amines generally remarkably color the resin varnish, so that they are hesitant to be used for applications requiring colorless transparency, for example. In addition, the composition of the polyimide resin having colorless transparency has many components with low reactivity, and the catalytic activity of the tertiary amine is generally low under such conditions. Therefore, the molecular weight of the resulting polyimide resin is low and sufficient mechanical properties are obtained. Characteristics, heat resistance, etc. may not be obtained. Furthermore, during long-term storage, the decomposition of the resin, which is considered to be caused by the catalyst, has been recognized.
JP-A 63-297414 Japanese Patent Laid-Open No. 8-113646 Japanese Patent Laid-Open No. 4-39323 JP 2005-68226 A

  In addition, although patent document 2 also has description which uses metals, such as titanium, cobalt, tin, and zinc, and a semimetal compound as a catalyst, when the present inventors tested, catalyst activity is low and it can use for actual superposition | polymerization. It was not a thing.

  As can be seen from the above examples, in the conventional techniques so far, there has been no known polyimide resin polymerization catalyst that simultaneously satisfies catalytic activity, heat resistance, electrical insulation, colorless transparency, resin stability, and the like. An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method for producing a polyimide resin having excellent characteristics and a polyimide resin varnish.

As a result of intensive studies to solve the above problems, the present inventors have finally completed the present invention. That is, this invention consists of the following structures.
(1) An aluminum complex selected from the group consisting of a compound represented by general formula (1), a compound represented by general formula (2), and a compound represented by general formula (3) as a polymerization catalyst, (A) A trivalent and / or tetravalent polycarboxylic acid derivative having an acid anhydride group, and (b) a polyisocyanate as a component and reacting in an organic solvent, a method for producing a polyimide resin.

（上記一般式中、Ｒ_１１、Ｒ_１２、Ｒ_１３、Ｒ_１４およびＲ_１５は同一でも異なっていてもよく、それぞれ水素原子、炭素数１〜１８のアルキル基、アリール基またはハロゲン置換アルキル基である。Ｒ_２１は炭素数１〜１８のアルキル基である）

(In the above general formula, R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ may be the same or different, and each represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group or a halogen-substituted alkyl group. R ₂₁ is an alkyl group having 1 to 18 carbon atoms)

(2) The method for producing a polyimide resin according to (1), wherein (c) alicyclic dicarboxylic acid is further reacted as an essential component.

(3) The method for producing a polyimide resin according to (1) or (2), wherein an alicyclic polyisocyanate is used as the polyisocyanate.

(4) The method for producing a polyimide resin according to any one of (1) to (3), wherein the logarithmic viscosity of the polyimide resin is 0.1 dl / g or more.

(5) The method for producing a polyimide resin according to any one of (1) to (4), wherein the polyimide resin is a polyamideimide resin.

(6) A polyimide resin varnish obtained from the production method according to any one of (1) to (5).

  By adopting the method of the present invention, it is possible to obtain a polyimide resin excellent in catalytic activity, heat resistance, electrical insulation, colorless transparency, resin stability, etc., which has been difficult to be satisfied at the same time. It is great to contribute to

The present invention will be described in detail below.
<Aluminum complex>
In the present invention, a specific aluminum complex is used as a polymerization catalyst. A specific aluminum complex is an aluminum chelate complex selected from the group consisting of a compound represented by the following general formula (1), a compound represented by (2), and a compound represented by (3). .

（上記一般式中、Ｒ_１１、Ｒ_１２、Ｒ_１３、Ｒ_１４およびＲ_１５は同一でも異なっていてもよく、それぞれ水素原子、炭素数１〜１８のアルキル基、アリール基またはハロゲン置換アルキル基である。Ｒ_２１は炭素数１〜１８のアルキル基である）

(In the above general formula, R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ may be the same or different, and each represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group or a halogen-substituted alkyl group. R ₂₁ is an alkyl group having 1 to 18 carbon atoms)

  Examples of chelate compounds coordinated to aluminum include β-diketones, β-ketoesters, salicylaldehydes, and the like.

  More specifically, as β-diketones, acetylacetone (2,4-pentanedione), propionylacetone (2,4-hexanedione), 2,4-heptanedione, 2,4-octanedione, 2,4 -Decanedione, 3,5-heptanedione, 2-methyl-3,5-heptanedione, 2,2-dimethyl-3,5-heptanedione, 2,6-dimethyl-3,5-heptanedione, dipivalo Ylmethane (2,2,6,6-tetramethyl-3,5-heptanedione), benzoylacetone (1-phenyl-1,3-butanedione), 1,3-diphenyl-1,3-propanedione, tri Fluoroacetylacetone (1,1,1-trifluoro-2,4-pentanedione), hexafluoroacetylacetone (1,1,1,5,5,5-hexa) Ruoro-2,4-pentanedione), and the like.

  Specific examples of acetoacetate esters include methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, isopropyl acetoacetate, butyl acetoacetate, pentyl acetoacetate, octyl acetoacetate, decyl acetoacetate, dodecyl acetoacetate, acetoacetic acid Examples include octadecyl, ethyl 2-acetopropionate, ethyl 2-acetobutyrate, ethyl 2-acetovalerate, ethyl propionyl acetate, and 3-one-ethyl caproate.

  More specifically, examples of salicylaldehydes include salicylaldehyde and 4-methoxysalicylaldehyde. Other examples include 2-hydroxyphenyl ketone and 2-hydroxybenzoic acid ester.

  In the general formulas (1) to (3), n is an integer of 1 to 3, and when n> 0, the bonded alkoxy group includes a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, and the like. Can be mentioned. Preferably n = 1, and more preferably n = 0. If n = 2 or more, the catalyst may be hydrolyzed, resulting in poor stability. In addition, a highly aggregated body may be formed, and the reaction may be difficult to proceed.

  These aluminum chelate complexes may be used alone or in combination of two or more. In this case, the coordinated chelate may undergo ligand exchange in a solvent. It is also possible to use mixed ligand complexes having different chelate components in one molecule.

  These complexes are usually easily synthesized by reacting an aluminum alcoholate with a corresponding β-diketone or the like in an organic solvent such as toluene, or reacting aluminum sulfate with a corresponding β-diketone in water. Alternatively, aluminum alcoholate and corresponding β-diketone and the like can be dissolved in a polymerization solvent and synthesized in situ for use. Furthermore, most of these complexes are easily soluble in general-purpose organic solvents and have sublimation properties, so that purification is easy. Preferred are acetylacetone, dipivaloylmethane, ethyl acetoacetate, and salicylaldehyde triskillate aluminum because of its low coloration, good catalytic activity, availability, and ease of obtaining a pure substance. It is a complex.

  The addition amount of the aluminum complex is preferably 0.01 to 2 mol% in terms of mol% with respect to the isocyanate component. When the addition amount is less than 0.01 mol%, the molecular weight is not sufficiently increased, and the coating film may be brittle. On the other hand, if it exceeds 2 mol%, the varnish is notably colored and the heat resistance may be lowered.

<Polyimide resin component>
As the component (a) constituting the polyimide resin of the present invention, a trivalent or tetravalent polycarboxylic acid derivative having an acid anhydride group that generally reacts with an isocyanate component or an amine component to form a polyimide resin is used. It is done. Examples of aromatic polycarboxylic acid derivatives include trimellitic anhydride, pyromellitic dianhydride, ethylene glycol bisanhydro trimellitate, propylene glycol bisanhydro trimellitate, 1,4-butanediol bisanhydro. Alkylene glycol bisanhydro trimellitate such as trimellitate, hexamethylene glycol bisanhydro trimellitate, polyethylene glycol bisanhydro trimellitate, polypropylene glycol bisanhydro trimellitate, 3,3 ', 4,4 '-Benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5 8-Naphthalenetetracarboxylic dianhydride 2,3,5,6-pyridinetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride , M-terphenyl-3,3 ', 4,4'-tetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, 1,1,1,3,3,3-hexafluoro- 2,2-bis (2,3- or 3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl) propane dianhydride, 2, 2-bis [4- (2,3- or 3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-bis [4- (2,3- or 3,4-dicarboxyphenoxy) phenyl] propane Examples thereof include dianhydrides and 1,3-bis (3,4-dicarboxyphenyl) -1,1,3,3-tetramethyldisiloxane dianhydride.

  Examples of the aliphatic or alicyclic polycarboxylic acid derivatives include butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, Cyclobutanetetracarboxylic dianhydride, hexahydropyromellitic dianhydride, cyclohex-1-ene-2,3,5,6-tetracarboxylic dianhydride, 3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3 -Ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-ethylcyclohexane-1- (1,2), 3,4-tetracarboxylic dianhydride 1-propylcyclo Xan-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1- (2,3), 3- (2,3) -tetracarboxylic dianhydride , Dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride, 1-propylcyclohexane -1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1- (2,3), 3- (2,3) -tetracarboxylic dianhydride , Dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2 .2] Octane-2,3,5,6-tetracarboxylic acid bismuth Things, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, hexahydroterephthalic trimellitic anhydride, and the like.

  These trivalent or tetravalent polycarboxylic acid derivatives may be used alone or in combination of two or more. In view of heat resistance, transparency, adhesion, cost, etc., pyromellitic dianhydride and trimellitic anhydride are preferable, and trimellitic anhydride is more preferable.

  In addition, in the polyimide-type resin of this invention, you may copolymerize aliphatic and aromatic polycarboxylic acid as needed in the range which does not impair the target performance. Examples of the aliphatic dicarboxylic acid include succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanedioic acid, eicosanedioic acid, 2-methylsuccinic acid, 2-methyladipic acid, 3 -Methyladipic acid, 3-methylpentanedicarboxylic acid, 2-methyloctanedicarboxylic acid, 3,8-dimethyldecanedicarboxylic acid, 3,7-dimethyldecanedicarboxylic acid, 9,12-dimethyleicosane diacid, fumaric acid, Examples of aromatic dicarboxylic acids such as maleic acid, dimer acid, and hydrogenated dimer acid include isophthalic acid, terephthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, oxydibenzoic acid, and stilbene dicarboxylic acid. These dicarboxylic acids may be used alone or in combination of two or more.

  Examples of the (c) component alicyclic dicarboxylic acid constituting the polyimide resin of the present invention include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 4,4. Examples include '-dicyclohexyl dicarboxylic acid. When importance is attached to heat resistance, transparency, adhesion, cost, etc., 1,4-cyclohexanedicarboxylic acid is preferable. The copolymerization amount of cyclohexanedicarboxylic acid is preferably 15 mol% or more. When the copolymerization amount of cyclohexanedicarboxylic acid is less than 15 mol%, the coloring becomes large and may not be used for optical applications.

  In the present invention, if necessary, a flexible component may be copolymerized. For example, aliphatic / aromatic polyester diols (trade name VYLON220 manufactured by Toyobo Co., Ltd.), aliphatic / aromatic polycarbonate diols (trade name PLACEL-CD220 manufactured by Daicel Chemical Industries, Ltd.), polycaprolactone Diols (Daicel Chemical Industries, trade name PLACEL-220, etc.), carboxy-modified acrylonitrile butadiene rubbers (Ube Industries, trade name Hycar CTBN 1300 × 13, etc.), polydimethylsiloxane diol, polymethylphenylsiloxane Examples thereof include polysiloxane derivatives such as diols and carboxy-modified polydimethylsiloxanes. Some of these are inserted into the molecular chain as polyurethane segments.

  The polyisocyanate of component (b) constituting the polyimide resin of the present invention is an alicyclic, aromatic, or aliphatic polyisocyanate. Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, transcyclohexane-1,4-diisocyanate, and hydrogenated m-xylylene diisocyanate. Considering heat resistance, transparency, adhesion, cost, etc., isophorone diisocyanate and 4,4′-dicyclohexylmethane diisocyanate are preferable.

  As aromatic polyisocyanates, for example, diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3 '-Or 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5, 2'- or 5,3'- or 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4 , 3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-3 , 3'-Diisocyanate Diphenylmethane-3,4'-diisocyanate, diphenylether-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6 -Diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4 '-[2,2bis (4-phenoxyphenyl) propane] diisocyanate, 3,3' or 2, 2'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'- or 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 3, , 3'-diethoxy Phenyl-4,4'-diisocyanate. In view of heat resistance, adhesion, cost, etc., diphenylmethane-4,4′-diisocyanate, tolylene-2,4-diisocyanate, and 3,3′-dimethylbiphenyl-4,4′-diisocyanate are preferable.

  Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. When importance is attached to transparency, the copolymerization amount of aromatic and aliphatic polyisocyanate is usually preferably 20 mol% or less, more preferably 10 mol% or less, based on the total isocyanate amount. When it exceeds 20 mol%, transparency is often impaired.

  Further, a polyisocyanate having 3 or more functional groups may be used, and a polyisocyanate stabilized with a blocking agent necessary for avoiding a change with time may be used. Examples of the blocking agent include alcohol, phenol and oxime, but there is no particular limitation. These polyisocyanates may be used alone or in combination of two or more. When the polymerization is carried out with an excess of isocyanate, the isocyanate group at the end of the resin can be blocked with a blocking agent such as alcohols, lactams or oximes after completion of the polymerization.

<Method for producing polyimide resin>
The compounding amount of (a) component trivalent or tetravalent polycarboxylic acid derivative having acid anhydride group, (b) component polyisocyanate, (c) component alicyclic dicarboxylic acid is the number of acid anhydride groups, The ratio of the number of carboxyl groups to the number of isocyanate groups is preferably such that the number of isocyanate groups / number of acid anhydride groups + number of carboxyl groups = 0.80-1.20. It is more preferable to set it as 0.90-1.10, and it is especially preferable to set it as 0.94-1.06. If it is less than 0.8 or exceeds 1.20, it becomes difficult to increase the molecular weight of the polyimide resin, and the heat resistance may be lowered, or the coating film may be brittle.

  The polymerization reaction of the modified polyimide resin used in the present invention is carried out by heat condensation in the presence of an organic solvent while removing freely generated carbon dioxide gas from the reaction system.

  Examples of the organic solvent include amide solvents such as N-methyl-2-pyrrolidone, N, N′-dimethylformamide, N, N′-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, dimethylurea, tetra For example, dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, sulfolane, etc. for sulfur solvents such as methyl urea, etc. For nitro solvents such as nitrobenzene, for example, diethylene glycol dimethyl ether (diglyme), diethylene glycol diethyl ether (ethyl diglyme) for ether solvents ), Triethylene glycol dimethyl ether (triglyme), triethylene glycol diethyl ether (ethyl triglyme), etc., ester solvents such as γ-butyrolactone, cellosolve acetate, etc. The ketone solvent such as methyl isobutyl ketone, cyclopentanone, cyclohexanone, isophorone, etc., in an aromatic hydrocarbon solvent such as toluene, xylene, Solvesso, and the like. These may be used alone or in combination of two or more.

  When producing the polyimide resin of the present invention, it is preferable to select and use a solvent that dissolves the resin to be produced. After polymerization, it is preferable to use a polyimide resin varnish and a suitable solvent for the paste as they are. preferable. In this case, complicated operations such as solvent replacement are eliminated, and it becomes possible to manufacture at low cost. N-methyl-2-pyrrolidone, N, N′-dimethylacetamide, 1,3-dimethyl-2-imidazo have properties that are excellent in solubility and economy and can be efficiently reacted in a homogeneous system. Lidinone, γ-butyrolactone and cyclohexanone are preferred. When emphasizing colorless transparency, γ-butyrolactone, cyclohexanone and 1,3-dimethyl-2-imidazolidinone are more preferable. When omitting solvent substitution and placing importance on low-temperature drying / curability, γ-butyrolactone and cyclohexanone are particularly preferred.

  In a non-nitrogen solvent varnish such as γ-butyrolactone and cyclohexanone, when a conventional alkali metal compound catalyst is used, haze tends to be generated, but in the polyimide resin varnish of the present invention using an aluminum chelate complex, haze is not Since it is not observed, it becomes possible to obtain a resin varnish of good quality.

  On the other hand, some of these have relatively low boiling points, such as aromatic hydrocarbon solvents such as toluene and xylene, ether solvents such as tetrahydrofuran, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, methanol, ethanol, isopropanol, etc. It is also possible to replace part or all with an alcohol solvent.

  The amount of solvent used is preferably 0.8 to 5.0 times (weight ratio) of the modified polyimide resin to be produced. If it is less than 0.8 times, the viscosity at the time of synthesis is too high, and the synthesis tends to be difficult due to the inability to stir. If it exceeds 5.0 times, the reaction rate tends to decrease.

  The reaction temperature is preferably 70 to 210 ° C, and more preferably 100 to 190 ° C. If it is less than 70 ° C., the reaction time becomes too long, and if it exceeds 210 ° C., a three-dimensional reaction occurs during the reaction and gelation tends to occur. The reaction time can be appropriately selected depending on the scale of the batch and the reaction conditions employed.

  As a method for producing the polyimide resin of the present invention, for example, (1) (a) component, (b) component and (c) component are used at a time and reacted to obtain a polyimide resin (2 ) After reacting (a) component and / or (c) component with an excessive amount of (b) component to synthesize an imide oligomer having an isocyanate group at the terminal, (a) component and / or (c) component And (3) an excess amount of the component (a) and / or the component (c) and the component (b) are reacted to form a carboxylic acid group and / or an acid anhydride. After synthesizing an imide-based oligomer having a physical group and / or a hydroxyl group, any method of adding a component (b) and reacting to obtain a polyimide-based resin may be used.

<Physical properties of polyimide resin>
The logarithmic viscosity of the polyimide resin of the present invention is preferably 0.1 dl / g or more, more preferably 0.2 dl / g or more. When the logarithmic viscosity is less than 0.1 dl / g, the heat resistance may be lowered or the coating film may be brittle. On the other hand, the upper limit is preferably 2.0 dl / g or less, more preferably 1.8 dl / g or less. When it exceeds 2.0 dl / g, it becomes difficult to dissolve in a solvent, and it tends to be insoluble during polymerization. In addition, the viscosity of the varnish becomes high and handling becomes difficult, and the adhesion to the base material decreases.

  The glass transition temperature of the polyimide resin of the present invention is preferably 80 ° C. or higher. More preferably, it is 130 degreeC or more, Most preferably, it is 180 degreeC or more. If it is less than 80 degreeC, when using for an optical use, heat resistance will run short and there exists a possibility that resin may block. Although an upper limit is not specifically limited, 400 degreeC or less is preferable from a solvent solubility viewpoint.

<Polyimide resin varnish>
The polyimide-based resin varnish of the present invention thus obtained, if necessary, for the purpose of improving, for example, mechanical properties, electrical properties, slipperiness, flame retardancy, etc., other resins and organic compounds, and An inorganic compound may be mixed or reacted to be used in combination. For example, lubricants (silica, talc, etc.), adhesion promoters, flame retardants (phosphorus, triazine, aluminum hydroxide, etc.), stabilizers (antioxidants, UV absorbers, polymerization inhibitors, etc.), plating activators , Organic and inorganic fillers (talc, titanium oxide, fluorine polymer fine particles, pigments, dyes, calcium carbide, etc.), other silicone compounds, fluorine compounds, isocyanate compounds, blocked isocyanate compounds, acrylic resins, urethane resins, polyester resins , Polyamide resins, epoxy resins, phenol resins, polycarbonate resins and organic compounds, or these curing agents, inorganic compounds such as silicon oxide, titanium oxide, calcium carbonate, iron oxide, thickeners, antifoaming agents Such conventional additives can be used in combination as long as the object of the present invention is not impaired.

  In order to describe the present invention more specifically, examples will be given below, but the present invention is not limited to the examples. In addition, the measured value described in the Example is measured by the following method.

<Logarithmic viscosity>
The modified polyimide resin was dissolved in N-methyl-2-pyrrolidone so that the polymer concentration was 0.5 g / dl, and the solution viscosity was measured with an Ubbelohde viscosity tube at 30 ° C.
The logarithmic viscosity was defined by the following formula.
(Logarithmic viscosity) = (lnηrel) / C
ln: natural logarithm,
ηrel: the viscosity ratio (−) of the solution to the pure solvent by solvent fall time measurement,
C: Solution concentration (g / dl)

<Preparation of film from polyimide resin varnish>
After the polyimide resin varnish was appropriately diluted with a solvent, it was applied to the glossy surface of an electrolytic copper foil having a thickness of 18 μm so as to have a thickness of 20 μm after drying. After drying with hot air at 80 ° C. for 10 minutes, heating is performed at 180 ° C. for 120 minutes in an air atmosphere to form a laminated film, and the copper foil of the obtained laminated film is removed by etching with a ferric chloride solution to obtain a film. It was. In the case of a polyimide resin varnish containing N-methyl-2-pyrrolidone as a solvent, after being applied to a polyester film E5100 manufactured by Toyobo Co., Ltd. so as to have a thickness of 20 μm after drying, and dried at 100 ° C. for 10 minutes. The film was peeled off from the polyester film, pasted on a metal frame of length 0.2 m × width 0.3 m, and further dried at 200 ° C. for 12 hours.

<Light transmittance of film>
The light transmittance in a wavelength region of 400 nm was measured with a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation) (film thickness 20 μm).

<Film mechanical properties>
Using a tensile tester (Orientec RTM-100), a sample cut into a strip shape having a width of 10 mm and a length of 100 mm in the longitudinal direction (MD direction) is sandwiched and fixed by a sample fixing chuck 20 mm above and below, and a tensile speed of 20 mm / And the distance between chucks was 40 mm and the temperature was 25 ° C. and 60 RH%, and the elongation at break and tensile modulus were obtained. In addition, the measurement was performed 5 times and the average value was employ | adopted.

<Film Tg>
Using a dynamic viscoelasticity measuring device (DVA-220 manufactured by IT meter side control), a sample of 4 mm width × 21 mm length was sandwiched between 3 mm each of the sample fixing chuck, the measurement length was 15 mm, the frequency was 110 Hz, and the heating rate was 4 ° C. The maximum point of tan δ when measured under the conditions of / min was defined as the glass transition temperature (Tg).

Example 1
Trimellitic anhydride (hereinafter abbreviated as TMA, purity 99.9%, trimellitic acid content 0.1%) in a four-necked 2 liter separable flask equipped with a stirrer, cooling tube, nitrogen inlet tube and thermometer 96.1 g (0.500 mol), 1,4-cyclohexanedicarboxylic acid (hereinafter CHDA); 86.1 g (0.500 mol), isophorone diisocyanate (hereinafter IPDI); 222.3 g (1.000 mol), γ-butyrolactone (Hereinafter referred to as γ-BL); 316.4 g and aluminum trisacetylacetonate (hereinafter referred to as Al (acac) 3); 0.7 g (0.2 mol%) as a catalyst; , Reacted for 1.5 hours. Next, after raising the temperature to 180 ° C. and reacting for 5 hours, 421.9 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) was added to dilute, and cooled to room temperature, thereby cooling to room temperature to produce a light yellow color having a non-volatile content of 30% by mass. A polyimide resin varnish A-1 was obtained.

Example 2
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA; 84.5 g (0.440 mol), CHDA; 75.8 g (0.440 mol), polycaprolactone diol ( Daicel Chemical Industries, Ltd. trade name PLACEL 220, molecular weight 2000, hereinafter abbreviated as PCL-2000); 240 g (0.120 mol), IPDI; 222.3 g (1.000 mol), γ-BL; 545.1 g and catalyst As an aluminum trisdipivaloylmethanate (hereinafter referred to as Al (dpm) 3); 1.2 g (0.2 mol%) was charged, the temperature was raised to 120 ° C. in a nitrogen stream, and the reaction was allowed to proceed for 1.5 hours. Next, after raising the temperature to 180 ° C. and reacting for 5 hours, 726.8 g of cyclohexanone (hereinafter referred to as CHX) was added, diluted, and cooled to room temperature, whereby a light yellow modified polyimide resin varnish A-2 having a nonvolatile content of 30 mass% was obtained. Got.

Example 3
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA; 91.1 g (0.474 mol), CHDA; 82.0 g (0.476 mol), carboxy-modified acrylonitrile butadiene Rubber (trade name Hycar CTBN 1300 × 13, molecular weight 3500, hereinafter abbreviated as CTBN 1300) manufactured by Ube Industries, Ltd .; 175 g (0.050 mol), IPDI; 229.2 g (1.031 mol), γ-BL; 489.2 g and Aluminum trisethyl acetoacetate (hereinafter referred to as Al (eaa) 3); 0.8 g (0.2 mol%) as a catalyst was charged, heated to 120 ° C. in a nitrogen stream, and reacted for 1.5 hours. Next, the temperature was raised to 180 ° C. and reacted for 5 hours, and then 652.2 g of CHX was added for dilution, followed by cooling to room temperature to obtain a yellow-modified polyimide resin varnish A-3 having a nonvolatile content of 30% by mass.

Example 4
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser, a nitrogen inlet tube and a thermometer, TMA: 178.1 g (0.927 mol), PCL-2000; 206 g (0.103 mol), IPDI: 133. 4 g (0.600 mol), 4,4′-dicyclohexylmethane diisocyanate (hereinafter H-MDI); 104.9 g (0.400 mol), γ-BL; 543.2 g and Al (acac) 3 as the catalyst; 0.7 g (0.2 mol%) was added, and the temperature was raised to 120 ° C. under a nitrogen stream and allowed to react for 1.5 hours. Subsequently, after heating up to 180 degreeC and making it react for 5 hours, 343.1g of CHX was added and diluted, and the pale yellow modified polyimide resin varnish A-4 of 38 mass% of non volatile matters was obtained by cooling to room temperature.

Example 5
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA: 96.1 g (0.500 mol), CHDA: 86.1 g (0.500 mol), IPDI: 222. 3 g (1.000 mol), γ-BL; 316.4 g and trissalicylaldehyde aluminum (hereinafter referred to as Al (sal) 3); 0.8 g (0.2 mol%) as a catalyst were charged at 120 ° C. under a nitrogen stream. The temperature was raised to 1.5 hours and allowed to react for 1.5 hours. Next, after raising the temperature to 180 ° C. and reacting for 5 hours, 421.9 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) was added to dilute, and cooled to room temperature, thereby cooling to room temperature to produce a light yellow color having a non-volatile content of 30% by mass. A polyimide resin varnish A-5 was obtained.

Example 6
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA; 199.8 g (1.040 mol), MDI; 250.3 g (1.000 mol), NMP; 831. 4 g and Al (acac) 3; 0.7 g (0.2 mol%) as a catalyst were charged, and the temperature was raised to 120 ° C. in a nitrogen stream, followed by reaction for 2 hours. Subsequently, after heating up to 160 degreeC and making it react for 4 hours, 129.3g of NMP was added and diluted, and the dark brown polyimide resin varnish A-6 of 35 mass% of non volatile matters was obtained by cooling to room temperature.

Comparative Example 1
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA; 84.5 g (0.440 mol), CHDA; 75.8 g (0.440 mol), PCL-2000; 240 g (0.120 mol), IPDI; 222.3 g (1.000 mol), γ-BL; 545.1 g and potassium fluoride (hereinafter referred to as KF); 1.2 g (2 mol%) as a catalyst were charged under a nitrogen stream. The temperature was raised to 120 ° C. and reacted for 1.5 hours. Subsequently, after heating up to 180 degreeC and making it react for 5 hours, 726.8g of CHX was added and diluted, and the pale yellow modified polyimide resin varnish A-7 of 30 mass% of non volatile matters was obtained by cooling to room temperature.

Comparative Example 2
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA; 91.1 g (0.474 mol), CHDA; 82.0 g (0.476 mol), CTBN1300; 175 g ( 0.050 mol), IPDI; 229.2 g (1.031 mol), γ-BL; 489.2 g and KF; 1.2 g (2 mol%) as a catalyst, and the temperature was raised to 120 ° C. under a nitrogen stream. The reaction was allowed for 5 hours. Subsequently, after heating up to 180 degreeC and making it react for 5 hours, 652.2g of CHX was added and diluted, and the yellow modified polyimide-type resin varnish A-8 of 30 mass% of non volatile matters was obtained by cooling to room temperature.

Comparative Example 3
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA; 84.5 g (0.440 mol), CHDA; 75.8 g (0.440 mol), PCL-2000; 240 g (0.120 mol), IPDI; 222.3 g (1.000 mol), γ-BL; 545.1 g were charged, the temperature was raised to 120 ° C. in a nitrogen stream without using a catalyst, and the reaction was performed for 1.5 hours. I let you. Subsequently, after heating up to 180 degreeC and making it react for 5 hours, 726.8g of CHX was added and diluted, and the light yellow modified polyimide resin varnish A-9 of 30 mass% of non volatile matters was obtained by cooling to room temperature.

Comparative Example 4
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA: 96.1 g (0.500 mol), CHDA: 86.1 g (0.500 mol), IPDI: 222. 3 g (1.000 mol), γ-BL; 316.4 g and 1,8-diazabicyclo [5.4.0] -7-undecene (hereinafter DBU); 1.5 g (1.0 mol%) as a catalyst, Under a nitrogen stream, the temperature was raised to 120 ° C. and reacted for 1.5 hours. Subsequently, after heating up to 180 degreeC and making it react for 5 hours, 421.9g of NMP was added and diluted, and the pale yellow modified polyimide-type resin varnish A-10 of 30 mass% of non volatile matters was obtained by cooling to room temperature.

Comparative Example 5
In a four-necked 2 liter separable flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, TMA; 199.8 g (1.040 mol), MDI; 250.3 g (1.000 mol), NMP; 831. 4 g was charged, and the temperature was raised to 120 ° C. in a nitrogen stream without using a catalyst, and the reaction was performed for 2 hours. Next, the temperature was raised to 160 ° C. and reacted for 4 hours. Then, 129.3 g of NMP was added and diluted, and cooled to room temperature to obtain a dark brown polyimide resin solution A-11 having a nonvolatile content of 35% by mass.

The results obtained in Examples 1 to 6 and Comparative Examples 1 to 5 are shown in Table 1.

  As is clear from Table 1, Comparative Examples 1 and 2 have good transparency, but the varnish has a haze and is poor in electrical insulation, and Comparative Example 3 has good transparency. It can be seen that film formation is impossible because the degree of polymerization does not increase, film formation is not possible because Comparative Example 4 does not increase the degree of polymerization, and Comparative Example 5 is inferior in mechanical properties because the degree of polymerization does not sufficiently increase.

  The polyimide resin production method and polyimide resin varnish of the present invention are useful as a film forming material for semiconductor elements, overcoat inks for various electronic components, solder resist inks, interlayer insulating films, paints, adhesives As such, it can be used in a wide range of electrical and electronic equipment, so it is important to invest industrially.

Claims (6)

An aluminum complex selected from the group consisting of a compound represented by the general formula (1), a compound represented by the general formula (2), and a compound represented by the general formula (3) is used as a polymerization catalyst, (a) A method for producing a polyimide resin comprising reacting a trivalent and / or tetravalent polycarboxylic acid derivative having an acid anhydride group and (b) a polyisocyanate in an organic solvent.

(In the above general formula, R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ may be the same or different, and each represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group or a halogen-substituted alkyl group. R ₂₁ is an alkyl group having 1 to 18 carbon atoms)   The method for producing a polyimide resin according to claim 1, wherein (c) an alicyclic dicarboxylic acid is reacted as an essential component.   The method for producing a polyimide resin according to claim 1 or 2, wherein an alicyclic polyisocyanate is used as the polyisocyanate.   The method for producing a polyimide resin according to any one of claims 1 to 3, wherein the logarithmic viscosity of the polyimide resin is 0.1 dl / g or more.   The method for producing a polyimide resin according to any one of claims 1 to 4, wherein the polyimide resin is a polyamideimide resin.   A polyimide resin varnish obtained from the production method according to claim 1.