JP6620428B2 - Polyimide resin - Google Patents

Description

  The present invention relates to a polyimide resin.

  In recent years, with the advent of an advanced information society, materials having both heat resistance and transparency are required in optical communication fields such as optical fibers and optical waveguides, and display device fields such as liquid crystal alignment films and color filters. .

  In addition to its excellent heat resistance, polyimide has excellent properties such as mechanical properties, chemical resistance, and electrical properties. Therefore, films made of polyimide are widely used in the fields of molding materials, composite materials, electric / electronic parts, display devices, and the like. However, the film is required to have higher transparency than ever. Further, when a layer made of polyimide is formed on a glass substrate to form a laminate, not only high transparency but also good adhesion to the glass substrate is required.

  Here, Patent Document 1 discloses that a photosensitive polyimide ink composition produced using cyclohexanecarboxylic dianhydride has good light transmittance.

JP 2010-209309 A

However, the light transmittance of Patent Document 1 has a problem with the light transmittance of the photosensitive polyimide ink composition itself, and no mention is made of the light transmittance when a film is used. Further, there is no disclosure about adhesion to a glass substrate.
As mentioned above, the subject of this invention is providing the polyimide resin which can form the polyimide resin layer which can exhibit favorable transparency and a glass base material, and high adhesiveness.

  The present inventors have found that the above problems can be solved by a specific polyimide resin having a carboxyl group, and have completed the invention.

That is, the present invention is as follows.
[1] A polyimide resin containing a structural unit represented by the following formula (1).

(Rx in Formula (1) is a tetravalent group having 4 to 22 carbon atoms including an alicyclic hydrocarbon ring structure and does not include an aromatic ring. X is a direct bond, a substituted or unsubstituted alkylene group, A carbonyl group, an ether group, a group represented by the following formula (a), or a group represented by the following formula (b), m1 and m2 are each independently an integer of 0 to 4, m3 and m4 are Each independently represents an integer of 0 to 5, m1 + m2 + m3 + m4 is 1 or more, and p represents an integer of 0 to 2. When p is 2, each of two Xs and two m2 to m4 is independent. Selected.)

[2] A laminate in which a polyimide resin layer containing the above-described polyimide resin of the present invention is formed on a glass substrate.

  According to the polyimide resin of the present invention, it is possible to form a polyimide resin layer that can exhibit good transparency and high adhesion to a glass substrate.

[Polyimide resin]
Hereinafter, (1) a polyimide resin and (2) a method for producing a polyimide resin will be described.

(1) Polyimide resin:
The polyimide resin of this invention contains the structural unit represented by following General formula (1).

(Rx in the formula (1) is a tetravalent group having 4 to 22 carbon atoms including an alicyclic hydrocarbon ring structure and does not include an aromatic ring. X is a single bond, a substituted or unsubstituted alkylene group, A carbonyl group, an ether group, a group represented by the following formula (a), or a group represented by the following formula (b), m1 and m2 are each independently an integer of 0 to 4, m3 and m4 are Each independently represents an integer of 0 to 5, m1 + m2 + m3 + m4 is 1 or more, and p represents an integer of 0 to 2. When p is 2, each of two Xs and two m2 to m4 is independent. Selected.)

First, in the general formula (1), Rx is a tetravalent group having 4 to 22 carbon atoms including an alicyclic hydrocarbon structure. By having the Rx, the polyimide resin of the present invention is particularly excellent in transparency. Furthermore, it has heat resistance and a low coefficient of thermal expansion. The alicyclic hydrocarbon structure may be saturated or unsaturated, but is preferably a saturated alicyclic hydrocarbon structure from the viewpoint of transparency.
Rx only needs to have at least one alicyclic hydrocarbon structure. Examples of the alicyclic hydrocarbon structure include cycloalkane rings such as cyclobutane ring, cyclopentane ring and cyclohexane ring, cycloalkene rings such as cyclohexene, bicycloalkane rings such as norbornane ring, and bicycloalkene rings such as norbornene. . Among these, preferably a cycloalkane ring and a bicycloalkane ring, more preferably a cycloalkane ring and a bicycloalkane ring having 4 to 6 member carbon atoms, still more preferably a cyclohexane ring and a bicyclohexane ring, and more More preferred is a cyclohexane ring.
Rx has 4 to 22 carbon atoms, preferably 4 to 18 carbon atoms, and more preferably 6 to 16 carbon atoms. From the viewpoint of the transparency of the polyimide resin, Rx is preferably composed only of an alicyclic hydrocarbon structure.

  Rx is a tetravalent group represented by the following general formulas (X1-1) and (X1-2) or (X1-3) from the viewpoint of the transparency of the polyimide resin (further, heat resistance and low thermal expansion coefficient). It is preferable that it is at least 1 type chosen from these, and it is more preferable that it is a tetravalent group represented by the following general formula (X1-2).

(R ^{3 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogenated alkyl group.)
In General Formulas (X1-2) and (X1-3), R ^{3 to} R ⁸ are preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom. Rx is more preferably a tetravalent group represented by the following structural formula (X1-4).

  In addition, due to the presence of the carboxyl group in the general formula (1), the adhesion with the glass substrate can be improved without impairing the transparency. In the general formula (1), any one of the following formulas (1-1) to (1-7) is preferable. Among the following formulas, the structural unit represented by formula (1-1) is preferable from a practical viewpoint.

  Moreover, it is preferable that a polyimide resin further contains the structural unit represented by following formula (2). By including the structural unit represented by the following formula (2), yellowing can be prevented and a colorless and transparent film (polyimide resin layer) can be formed.

(In formula (2), Ry is a tetravalent group having 4 to 22 carbon atoms containing an alicyclic hydrocarbon ring structure, and does not contain an aromatic ring. Y is a residue of a single bond or a divalent aryl group. Q1 and q2 are each independently an integer of 1 to 4, Ra and Rb each independently represent a methyl group, a trifluoromethyl group, a chloro group, a hydroxyl group or a methoxy group, and Ra and Rb are When there are a plurality of Ra and Rb, they may be the same or different, and Ra and Rb are preferably a methyl group or a trifluoromethyl group. )

  In the above formula (2), examples of the residue of the divalent aryl group of Y include the following divalent groups.

The structural unit represented by the formula (2) is a structural unit represented by any one of the following formulas (2-1) to (2-3) from the viewpoint of good colorless transparency of the formed film. Preferably, there is a structural unit represented by the following formula (2-1), and in the formula (2-1), Ra and Rb are preferably a methyl group or a trifluoromethyl group.

Even if the polyimide resin of this invention is comprised by the structural unit represented by Formula (1), it may further contain the structural unit represented by Formula (2). When the structural unit represented by the formula (2) is included, the structural unit represented by the formula (1) with respect to the total of the structural unit represented by the formula (1) and the structural unit represented by the formula (2) The ratio is preferably 40 mol% or more, more preferably 45 mol% or more, and further preferably 50 mol% or more. A colorless and transparent film | membrane can be formed because it is 40 mol% or more.
Moreover, when the structural unit represented by Formula (2) is included, the combination of the structural unit represented by Formula (1-1) and the structural unit represented by Formula (2-1) is formed. It is preferable from the viewpoint of improving the colorless transparency of the film. In particular, the formula (2-1) is preferably represented by the following formula.

  Moreover, the polyimide resin of this invention does not contain aromatic rings, such as phenylene and biphenylene, in each of Rx of Formula (1) and Ry of Formula (2). High transparency can be maintained by not containing an aromatic ring.

  The number average molecular weight of the polyimide resin of the present invention is preferably 5,000 to 100,000 from the viewpoint of mechanical strength of the resulting polyimide film. The number average molecular weight of the polyimide resin can be measured by gel filtration chromatography or the like.

(2) Production of polyimide resin:
The polyimide resin of the present invention can be produced by reacting a specific tetracarboxylic acid component with a specific diamine component.
The tetracarboxylic acid component contains a tetracarboxylic acid containing an alicyclic hydrocarbon structure or a derivative thereof (and, if necessary, a tetracarboxylic acid containing an aromatic ring or a derivative thereof). The diamine component contains a diamine represented by the following structural formula (A1) (and a diamine represented by the following structural formula (A2) as necessary).

  Note that X, m1, m2, and p in the structural formula (A1) and Y, Ra, Rb, q1, and q2 in the structural formula (A2) are the same symbols as those in the above-described formulas (1) and (2). Is the same as

The tetracarboxylic acid containing an alicyclic hydrocarbon structure is preferably a compound in which four carboxyl groups are directly bonded to an alicyclic hydrocarbon, and may contain an alkyl group in the structure. The tetracarboxylic acid preferably has 8 to 26 carbon atoms.
Examples of the tetracarboxylic acid having an alicyclic hydrocarbon structure include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,4,5-cyclopentanetetracarboxylic acid, 1,2,4,5- Examples include cyclohexanetetracarboxylic acid, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid, dicyclohexyltetracarboxylic acid, or positional isomers thereof.

Examples of the tetracarboxylic acid derivative containing an alicyclic hydrocarbon structure include anhydrides or alkyl esters of the tetracarboxylic acid. The tetracarboxylic acid derivative is preferably one having 8 to 38 carbon atoms. Examples of the tetracarboxylic acid anhydride containing an alicyclic hydrocarbon structure include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyltetracarboxylic dianhydride Examples thereof include anhydrides and positional isomers thereof.
The alkyl ester of the tetracarboxylic acid containing an alicyclic hydrocarbon structure preferably has 1 to 3 carbon atoms in the alkyl, for example, dimethyl tetracarboxylic acid containing the alicyclic hydrocarbon structure described above. Examples include esters, diethyl esters, and dipropyl esters.
As the tetracarboxylic acid or derivative thereof containing an alicyclic hydrocarbon structure, at least one compound selected from the above may be used alone, or two or more compounds may be used in combination.

  Among the tetracarboxylic acid components containing the alicyclic hydrocarbon structure, cycloalkanetetracarboxylic acid, bicycloalkanetetracarboxylic acid or acid dianhydrides thereof are preferable, and the cycloalkanetetracarboxylic acid having 4 to 6 ring member carbon atoms. More preferred are acids, bicycloalkanetetracarboxylic acids having 4 to 6 ring carbon atoms, or acid dianhydrides thereof, and 1,2,4,5-cyclohexanetetracarboxylic acid or acid dianhydrides are more preferred. .

In addition, the tetracarboxylic acid component used for the polyimide resin of this invention may contain the tetracarboxylic acid component which does not impair all the physical properties of a polyimide resin and does not contain an alicyclic hydrocarbon structure and an aromatic ring. Examples of the tetracarboxylic acid component include 1,2,3,4-butanetetracarboxylic acid, 1,2,3,4-pentanetetracarboxylic acid, and derivatives thereof.
The amount of the tetracarboxylic acid component containing neither an alicyclic hydrocarbon structure nor an aromatic ring is preferably 10 mol% or less, more preferably 5 mol% or less, still more preferably, based on the total tetracarboxylic acid component. 1 mol% or less.

  The diamine component used for the polyimide resin of the present invention includes a diamine represented by the structural formula (A1) as described above, and a diamine represented by the structural formula (A2) as necessary.

  Examples of the diamine represented by the structural formula (A1) include the following diamines.

  Examples of the diamine represented by the structural formula (A2) include the following diamines. Of these, A2-1 and A2-4 are preferable.

  The diamine component used in the polyimide resin of the present invention may contain other diamine components other than the diamines represented by the structural formula (A1) and the structural formula (A2) as long as various physical properties of the polyimide resin are not impaired. . There is no restriction | limiting in particular as this other diamine, An aliphatic diamine, an aromatic ring containing diamine, etc. are mentioned. From the viewpoint of the heat resistance of the polyimide resin, an aromatic ring-containing diamine is preferred.

Examples of the aliphatic diamine include alicyclic hydrocarbon structure-containing diamines and chain aliphatic diamines. For example, 1,2-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane, 1, 4-bis (aminomethyl) cyclohexane, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4′-diaminodicyclohexylmethane, 4,4′-methylenebis (2-methylcyclohexyl) Amine), Carboxydiamine, Limonenediamine, Isophoronediamine, Norbornanediamine, Bis (aminomethyl) tricyclo [5.2.1.0 ^2,6 ] decane, 3,3′-dimethyl-4,4′-diaminodicyclohexyl Methane, 4,4′-diaminodicyclohexylpropane, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1, 11-Undecamethylenediamine, 1,12-dodecamethylenediamine, 2,2 ′-(ethylenedioxy) bis (ethyleneamine) and the like can be mentioned.
Examples of the aromatic ring-containing diamine include orthoxylylenediamine, metaxylylenediamine, paraxylylenediamine, 1,2-diethynylbenzenediamine, 1,3-diethynylbenzenediamine, 1,4-diethynylbenzenediamine, 1 , 2-diaminobenzene, 1,3-diaminobenzene, 1,4-diaminobenzene, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, α, α′-bis (4-aminophenyl) 1,4-diisopropylbenzene, α, α′-bis (3-aminophenyl) -1,4-diisopropylbenzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane 2,6-diaminonaphthalene, 1,5-diaminonaphthalene, 4,4′-diaminobenzene Zuanirido, 3,4'-diaminodiphenyl benzanilide and the like.
The said diamine component may be used independently and may be used in combination of 2 or more type.

  The usage-amount of the said other diamine component is 20 mol% or less with respect to all the diamine components, Preferably it is 10 mol% or less, More preferably, it is 5 mol% or less, More preferably, it is 1 mol% or less.

  When the polyimide resin of the present invention is produced, the charge ratio of the tetracarboxylic acid component and the diamine component is preferably such that the diamine component is 0.9 to 1.1 mol with respect to 1 mol of the tetracarboxylic acid component. .

  Moreover, when manufacturing the polyimide resin of this invention, you may use terminal blocker other than the said tetracarboxylic acid component and the said diamine component. As end-capping agents, monoamines or dicarboxylic acids are preferred. The amount of the terminal blocking agent to be introduced is preferably 0.0001 to 0.1 mol, particularly preferably 0.001 to 0.06 mol, per 1 mol of the tetracarboxylic acid component. Examples of monoamine end-capping agents include methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine, 3- Ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline and the like are recommended. Of these, benzylamine and aniline can be preferably used. As the dicarboxylic acid end-capping agent, dicarboxylic acids are preferable, and a part of them may be closed. For example, phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3,4-benzophenone dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, cyclopentane-1,2 -Dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid and the like are recommended. Of these, phthalic acid and phthalic anhydride can be suitably used.

There is no restriction | limiting in particular in the method of making the above-mentioned tetracarboxylic acid component and a diamine component react, A well-known method can be used.
As a specific reaction method, (1) a tetracarboxylic acid component, a diamine component, and a reaction solvent are charged into a reactor, and stirred at room temperature to 80 ° C. for 0.5 to 30 hours as necessary. (2) A diamine component and a reaction solvent are charged into a reactor and dissolved, and then a tetracarboxylic acid component is charged and, if necessary, at room temperature to 80 ° C. for 0.5 to 30 hours. Stirring, then raising the temperature and conducting the imidation reaction, (3) charging the tetracarboxylic acid component, diamine component, and reaction solvent into the reactor and raising the temperature immediately to conduct the imidization reaction, etc. It is done.

  The reaction solvent used for the production of the polyimide resin may be any solvent that does not inhibit the imidization reaction and can dissolve the polyimide resin to be produced. For example, an aprotic solvent, a phenol solvent, an ether solvent, a carbonate solvent, and the like can be given.

  Specific examples of the aprotic solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 1,3-dimethylimidazolidinone, tetramethylurea and the like. Amide solvents, lactone solvents such as γ-butyrolactone and γ-valerolactone, phosphorus-containing amide solvents such as hexamethylphosphoric amide and hexamethylphosphine triamide, sulfur-containing dimethylsulfone, dimethylsulfoxide, sulfolane and the like Examples of the solvent include ketone solvents such as acetone, cyclohexane and methylcyclohexane, amine solvents such as picoline and pyridine, and ester solvents such as acetic acid (2-methoxy-1-methylethyl).

Specific examples of the phenol solvent include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4 -Xylenol, 3,5-xylenol, etc. are mentioned.
Specific examples of the ether solvent include 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, bis [2- (2-methoxyethoxy) ethyl]. Ether, tetrahydrofuran, 1,4-dioxane and the like can be mentioned.
Specific examples of the carbonate solvent include diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, and the like.
Among the above reaction solvents, amide solvents or lactone solvents are preferable. Moreover, you may use said reaction solvent individually or in mixture of 2 or more types.

  In the imidization reaction, it is preferable to perform the reaction using a Dean Stark apparatus or the like while removing water generated during production. By performing such an operation, the degree of polymerization and the imidization rate can be further increased.

In the above imidation reaction, a known imidation catalyst can be used. Examples of the imidization catalyst include a base catalyst and an acid catalyst.
Base catalysts include pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine, tripropylamine, tributylamine, imidazole, N, N-dimethylaniline. And organic base catalysts such as N, N-diethylaniline and inorganic base catalysts such as potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, and the like.
Examples of the acid catalyst include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, oxybenzoic acid, terephthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, and the like. Is mentioned. The above imidation catalysts may be used alone or in combination of two or more.
Among the above, from the viewpoint of handleability, it is preferable to use a base catalyst, more preferably an organic base catalyst, and still more preferably triethylamine.

  The temperature of the imidation reaction is preferably 120 to 250 ° C, more preferably 160 to 210 ° C, from the viewpoint of the reaction rate and the suppression of gelation and the like. The reaction time is preferably 0.5 to 10 hours after the start of distillation of the produced water.

The polyimide resin of the present invention can be a polyimide film having a total light transmittance of preferably 85% or more, for example, when the film has a thickness of 30 μm. The total light transmittance is more preferably 88% or more, and still more preferably 89% or more.
Further, the yellowness (YI) is preferably 11 or less, and more preferably 5 or less.
Specifically, the total light transmittance and YI of the polyimide film can be measured by the methods described in Examples.
In addition, even when it is set as the laminated body mentioned later, it can be said that the total light transmittance of the formed polyimide resin layer is equivalent to the above.

  Although the polyimide resin of this invention has the solubility to an organic solvent normally, the solubility to an organic solvent may be low depending on the structure of a polyimide resin. In that case, from the viewpoint of handleability and workability, the above-described imidization reaction may be performed using a composition containing a polyamic acid which is a precursor of a polyimide resin (polyamic acid composition described later).

  The polyamic acid includes a repeating structural unit represented by the following general formula (1a), and preferably includes a repeating structural unit represented by the following general formula (2a). These contents are suitably adjusted according to the composition of the desired polyimide. Other preferred embodiments are the same as those of the polyimide resin.

(Each symbol in the above formulas (1a) and (2a) is the same as described above. R ³¹ and R ³² are each independently a hydrogen atom or an alkyl group, preferably a hydrogen atom or a carbon number of 1 to 3 alkyl groups.)

The polyamic acid can be obtained by reacting the aforementioned tetracarboxylic acid component with a diamine component. There is no restriction | limiting in particular in the method to make it react, A well-known method can be used.
As a specific reaction method, (1) a method in which a tetracarboxylic acid component, a diamine component, and a solvent are charged into a reactor and stirred at 0 to 120 ° C., preferably 5 to 80 ° C. for 1 to 72 hours, ( 2) A method in which a diamine component and a solvent are charged into a reactor and dissolved, and then a tetracarboxylic acid component is charged, followed by stirring in a range of 0 to 120 ° C., preferably 5 to 80 ° C. for 1 to 72 hours, and the like. . Of the above, the production method (2) is preferred.
When the reaction is performed at 80 ° C. or lower, the molecular weight of the resulting polyamic acid does not vary depending on the temperature history during polymerization, and the progress of thermal imidization can be suppressed, so that polyamic acid can be produced stably. .

  The solvent used for the production of the polyamic acid may be any one that can dissolve the produced polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, γ-butyrolactone, γ-valerolactone, dimethyl sulfoxide, 1,4-dioxane, cyclohexanone and the like can be mentioned. You may use the said solvent individually or in mixture of 2 or more types.

In the production method of (1) above, the solution in which the diamine component and the tetracarboxylic acid component are dissolved in the above solvent is stirred, but is stirred at 0 to 120 ° C., preferably 5 to 80 ° C. for 1 to 72 hours. To obtain a solution containing polyamic acid. In the production method (2), the tetracarboxylic acid component is gradually added while stirring the solution in which the diamine component is dissolved in the solvent, and the temperature is 0 to 120 ° C., preferably 5 to 80 ° C. A solution containing polyamic acid is obtained by stirring for ˜72 hours.
The concentration of the polyamic acid in the obtained polyamic acid solution is usually 1 to 50% by mass, preferably 3 to 35% by mass, more preferably 10 to 10% by mass in the polyamic acid solution from the viewpoint of use as a polyamic acid composition. It is in the range of 30% by mass.

The polyamic acid composition contains the polyamic acid obtained as described above. Even if this polyamic acid composition is used, the polyimide resin of the present invention can be obtained.
The polyamic acid composition preferably further contains an imidization catalyst and a dehydration catalyst from the viewpoint of efficiently proceeding with imidization. The imidation catalyst may be an imidization catalyst having a boiling point of 40 ° C. or higher and 180 ° C. or lower, and an amine compound having a boiling point of 180 ° C. or lower is preferable. If the boiling point is an imidization catalyst having a temperature of 180 ° C. or less, the polyimide resin layer is formed and then colored at the time of drying at a high temperature, and the appearance is not impaired. Moreover, if it is an imidation catalyst whose boiling point is 40 degreeC or more, possibility that it will volatilize before imidation fully progresses can be avoided.
Examples of the amine compound suitably used as an imidation catalyst include pyridine and picoline. The above imidation catalysts may be used alone or in combination of two or more.
Examples of the dehydration catalyst include acetic anhydride, propionic anhydride, n-butyric anhydride, benzoic anhydride, trifluoroacetic anhydride, and other acid anhydrides; carbodiimide compounds such as dicyclohexylcarbodiimide; and the like. You may use these individually or in combination of 2 or more types.

  The polyamic acid composition may contain additives such as an antioxidant, a light stabilizer, a surfactant, a flame retardant, and a plasticizer as long as the effects of the present invention are not impaired.

The polyimide resin of the present invention can be obtained by heating and dehydrating and ring-closing the polyamic acid composition.
The heating temperature is usually 100 to 400 ° C, preferably 200 to 350 ° C, more preferably 250 to 300 ° C. The heating time is usually 1 minute to 6 hours, preferably 5 minutes to 2 hours, and more preferably 15 minutes to 1 hour.
Examples of the heating atmosphere include air gas, nitrogen gas, oxygen gas, hydrogen gas, nitrogen / hydrogen mixed gas, etc. In order to suppress coloring of the resulting polyimide resin, nitrogen gas having an oxygen concentration of 100 ppm or less, hydrogen concentration Is preferably a nitrogen / hydrogen mixed gas containing 0.5% or less.

As a method for producing a laminate using the polyamic acid composition, for example, after applying the polyamic acid composition, heating drying and dehydration ring closure under the above conditions, and then peeling from the substrate can be used. There is no restriction | limiting in particular in the coating method of a polyamic-acid composition, A well-known method can be used.
The thickness of the polyimide resin layer produced using the polyamic acid composition is usually 0.1 to 500 μm, preferably 1 to 250 μm, more preferably 5 to 100 μm, and still more preferably 10 to 50 μm.

In addition, even if it contains various additives in the range which does not impair the effect of this invention, it is good also as a polyimide resin composition. Examples of the additive include an antioxidant, a light stabilizer, a surfactant, a flame retardant, a plasticizer, and a polymer compound other than the polyimide resin.
Moreover, there is no restriction | limiting in particular in the preparation method of the said resin composition, A well-known method can be used.

  Moreover, the solid content concentration of the resin composition can be appropriately selected according to workability and the like when forming a laminate described later, and the solid content concentration and viscosity of the composition can be added by adding an organic solvent. May be adjusted. The organic solvent is not particularly limited as long as it can dissolve the polyimide resin.

[Laminate]
The laminate of the present invention is formed by forming a polyimide resin layer containing the polyimide resin of the present invention on a glass substrate.
The laminated body of this invention should just have at least 1 layer of a polyimide resin layer, and may have two or more layers.

There is no restriction | limiting in particular in the manufacturing method of the laminated body of this invention, A well-known method can be used.
The laminated body of the present invention includes, for example, a method in which the solution of the polyimide resin of the present invention is applied on a glass substrate by a known method and held at 100 to 400 ° C. for 1 to 360 minutes to volatilize the organic solvent. It is done.

  Although the thickness of the polyimide resin layer which comprises the laminated body of this invention can be suitably selected according to the use etc. of a laminated body, Preferably it is 1-250 micrometers, More preferably, it is the range of 5-100 micrometers. In addition, when a laminated body has two or more polyimide resin composition layers, the thickness of a polyimide resin composition layer means the total thickness of each layer.

  The laminated body of this invention is used suitably for various members, such as an optical member.

  Hereinafter, the present invention will be described specifically by way of examples. However, this invention is not restrict | limited at all by these Examples.

Evaluation of the polyimide films obtained in Examples and Comparative Examples was performed as follows.
(1) Total light transmittance, yellow index (YI)
It measured using the color / turbidity simultaneous measuring device (COH400) by Nippon Denshoku Industries Co., Ltd.
(2) Adhesion with glass substrate A polyimide resin solution is applied on a glass plate and, as will be described later, a polyimide film under conditions of 100 ° C for 60 minutes on a hot plate and 250 ° C for 2 hours in a hot air dryer. The ease of peeling of the polyimide film when peeled by hand was evaluated by five monitors.
2 points when the polyimide film did not peel, 1 point when strong force was required to peel, 0 point when peeled easily, and averaged 5 people, 10 to 7 points A The results are shown in Table 1 with B being 6 to 4 points and C being 0 to 3 points.

(Synthesis of 1,2,4,5-cyclohexanetetracarboxylic dianhydride)
A 5 liter Hastelloy (HC22) autoclave was charged with 552 g of pyromellitic acid, 200 g of a catalyst in which rhodium was supported on activated carbon (manufactured by NE Chemcat Corporation), and 1656 g of water. The reactor was purged with nitrogen gas. Next, the inside of the reactor was replaced with hydrogen gas, and the temperature of the reactor was increased to 60 ° C. with a hydrogen pressure of 5.0 MPa. The reaction was carried out for 2 hours while maintaining the hydrogen pressure at 5.0 MPa. The hydrogen gas in the reactor was replaced with nitrogen gas, the reaction solution was extracted from the autoclave, and the reaction solution was filtered while hot to separate the catalyst. The filtrate was concentrated by evaporating water under reduced pressure using a rotary evaporator to precipitate crystals. The precipitated crystals were solid-liquid separated at room temperature and dried to obtain 481, g (yield: 85.0%) of 1,2,4,5-cyclohexanetetracarboxylic acid.
Subsequently, 450 g of the obtained 1,2,4,5-cyclohexanetetracarboxylic acid and 4000 g of acetic anhydride were charged into a 5-liter glass separable flask (with Dimroth condenser), and the inside of the reactor was stirred. Replaced with nitrogen gas. The temperature was raised to the reflux temperature of the solvent under a nitrogen gas atmosphere, and the solvent was refluxed for 10 minutes. While stirring, the mixture was cooled to room temperature to precipitate crystals. The precipitated crystals were separated into solid and liquid and dried to obtain primary crystals. Further, the separated mother liquor was concentrated under reduced pressure using a rotary evaporator to precipitate crystals. The crystals were separated into solid and liquid and dried to obtain secondary crystals. The primary crystal and the secondary crystal were combined to obtain 375 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (anhydrous yield of 96.6%).

(Preparation of polyimide resin solution A)
In a 300 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 17.9 g (0.118 mol) of 3,5-diaminobenzoic acid under a nitrogen stream Then, 51.2 g of γ-butyrolactone and 15.2 g of N, N-dimethylacetamide were charged and dissolved as a solvent, and then 26.4 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized previously. (0.118 mol) and 0.5 g (0.005 mol) of triethylamine as an imidization catalyst were added all at once. After completion of the dropwise addition, the temperature was raised to 180 ° C., refluxed for 5 hours while distilling off the distillate as needed, the reaction was terminated, air-cooled until the internal temperature reached 100 ° C., and N, N-dimethyl as a diluent solvent. 93.6 g of acetamide was added and cooled with stirring to obtain a polyimide resin solution A having a solid content concentration of 20% by weight.

(Preparation of polyimide resin solution B)
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 8.2 g (0.054 mol) of 3,5-diaminobenzoic acid under a nitrogen stream 2,2′-dimethyl-4,4′-diaminobiphenyl (11.5 g, 0.054 mol), 52.7 g of γ-butyrolactone and 13.2 g of N, N-dimethylacetamide as a solvent were added and dissolved. Thereafter, 25.3 g (0.108 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized earlier and 0.5 g (0.005 mol) of triethylamine as an imidization catalyst were added all at once. . After completion of the dropwise addition, the temperature was raised to 180 ° C., refluxed for 5 hours while distilling off the distillate as needed, the reaction was terminated, air-cooled until the internal temperature reached 100 ° C., and N, N-dimethyl as a diluent solvent. 94.2 g of acetamide was added and cooled with stirring to obtain a polyimide resin solution B having a solid concentration of 20% by weight.

(Preparation of polyimide resin solution C)
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 13.0 g (0.086 mol) of 3,5-diaminobenzoic acid under a nitrogen stream 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 42.9 g of γ-butyrolactone and 10.7 g of N, N-dimethylacetamide as a solvent. After being charged and dissolved, 24.0 g (0.107 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized previously and 5 g (0.05 mol) of triethylamine as an imidization catalyst were collectively. Added at. After completion of the dropwise addition, the temperature was raised to 180 ° C., refluxed for 5 hours while distilling off the distillate as needed, the reaction was terminated, air-cooled until the internal temperature reached 100 ° C., and N, N-dimethyl as a diluent solvent. 106.4 g of acetamide was added and cooled with stirring to obtain a polyimide resin solution C having a solid concentration of 20% by weight.

<Example 1>
The obtained polyimide resin solution A is applied onto a glass plate with a bar coater, and a polyimide resin layer is formed on a glass substrate (thickness: 5 mm, material: soda glass) as a glass substrate as follows. A laminate was prepared and the adhesion was evaluated as described above. The results are shown in Table 1.
The polyimide resin layer is formed on the glass substrate by first applying the polyimide resin solution A to the glass substrate (thickness: 5 mm), holding it on a hot plate at 100 ° C. for 60 minutes, and volatilizing the solvent to self-support. A colorless and transparent primary dry film having properties was obtained. While the film was formed on glass, the film was heated in a hot air dryer at 250 ° C. for 2 hours to evaporate the solvent to obtain a film having a thickness of 50 μm.
The above-described evaluation (total light transmittance, yellow index) was performed on the obtained film. The results are shown in Table 1.

<Example 2>
A polyimide film having a thickness of 50 μm was obtained in the same manner as in Example 1 except that the polyimide resin solution A was changed to the polyimide resin solution B. The above-described evaluation was performed on the obtained film. The results are shown in Table 1.

<Example 3>
A polyimide film having a thickness of 50 μm was obtained in the same manner as in Example 1 except that the polyimide resin solution A was changed to the polyimide resin solution C. The above-described evaluation was performed on the obtained film. The results are shown in Table 1.

<Comparative Example 1>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 2,2′-dimethyl-4,4′-diaminobiphenyl 18. 1 g (0.085 mol), 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl 6.8 g (0.021 mol), γ-butyrolactone 48.0 g as a solvent and N, N -12.0 g of dimethylacetamide was charged and dissolved, then 23.9 g (0.106 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized previously and 5 g of triethylamine as an imidization catalyst ( 0.05 mol) was added all at once. After completion of the dropwise addition, the temperature was raised to 180 ° C., refluxed for 5 hours while distilling off the distillate as needed, the reaction was terminated, air-cooled until the internal temperature reached 100 ° C., and N, N-dimethyl as a diluent solvent. 120.0 g of acetamide was added, and the mixture was cooled with stirring to obtain a polyimide resin solution D having a solid content of 20% by weight.
The obtained polyimide resin solution D is applied onto a glass plate with a bar coater, and a polyimide resin layer is formed on a glass substrate (thickness: 5 mm, material: soda glass) as a glass substrate as follows. A laminate was prepared and the adhesion was evaluated as described above. The results are shown in Table 1.
The polyimide resin layer is formed on the glass substrate by first applying the polyimide resin solution D to the glass substrate (thickness: 5 mm), holding it on a hot plate at 100 ° C. for 60 minutes, and volatilizing the solvent to self-support. A colorless and transparent primary dry film having properties was obtained. While the film was formed on glass, the film was heated in a hot air dryer at 250 ° C. for 2 hours to evaporate the solvent to obtain a film having a thickness of 50 μm.
The above-described evaluation (total light transmittance, yellow index) was performed on the obtained film. The results are shown in Table 1.

Claims (10)

A polyimide resin containing a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2) .

(Rx in Formula (1) is a tetravalent group represented by the following Formula (X1-2), and R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom, or a carbon number of 1 to 6. X represents a single bond, a substituted or unsubstituted alkylene group, a carbonyl group, an ether group, a group represented by the following formula (a), or a group represented by the following formula (b). M1 and m2 are each independently an integer of 0 to 4, m3 and m4 are each independently an integer of 0 to 5, m1 + m2 + m3 + m4 is 1 or more, and p represents an integer of 0 to 2. (If p is 2, each of the two Xs and the two m2 to m4 is independently selected.)


(In formula (2), Ry is a tetravalent group having 4 to 22 carbon atoms containing an alicyclic hydrocarbon ring structure and does not contain an aromatic ring. Y is a single bond, and q1 and q2 are independent of each other. And Ra and Rb each independently represents a methyl group, a trifluoromethyl group, a chloro group, a hydroxyl group or a methoxy group, and Ra and Rb are bonded to each other to form a methylene group. When there are a plurality of Ra and Rb, they may be the same or different.) The proportion of the structural unit represented by the formula (1) to the sum of structural units represented by the formula (1) and a constitutional unit wherein the formula (2) is, according to claim 1 is 40 mol% or more Polyimide resin. The polyimide resin according to claim 1 or 2 , wherein the structural unit represented by the formula (2) is a structural unit represented by the following formula (2-1).

(Ry, Ra, and Rb in Formula (2-1) are the same as in Formula (2).) The polyimide resin according to any one of claims 1 to 3, wherein Ra and Rb in the formula (2) or the formula (2-1) are a methyl group or a trifluoromethyl group. The polyimide resin according to claim 4 , wherein Ra and Rb in the formula (2) or the formula (2-1) are trifluoromethyl groups. A polyimide resin comprising a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2), represented by the structural unit represented by the formula (1) and the formula (2): The polyimide resin whose ratio of the structural unit represented by Formula (1) with respect to the sum total of a structural unit is 40 mol% or more .

(Rx in Formula (1) is a tetravalent group represented by the following Formula (X1-2), and R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom, or a carbon number of 1 to 6. X represents a single bond, a substituted or unsubstituted alkylene group, a carbonyl group, an ether group, a group represented by the following formula (a), or a group represented by the following formula (b). M1 and m2 are each independently an integer of 0 to 4, m3 and m4 are each independently an integer of 0 to 5, m1 + m2 + m3 + m4 is 1 or more, and p represents an integer of 0 to 2. (If p is 2, each of the two Xs and the two m2 to m4 is independently selected.)


(In formula (2), Ry is a tetravalent group having 4 to 22 carbon atoms containing an alicyclic hydrocarbon ring structure, and does not contain an aromatic ring. Y is a residue of a single bond or a divalent aryl group. Q1 and q2 are each independently an integer of 1 to 4, and Ra and Rb are each independently a methyl group or a trifluoromethyl group, and when there are a plurality of Ra and Rb, they may be the same or different. May be.) A polyimide resin containing a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2) .

(Rx in Formula (1) is a tetravalent group represented by the following Formula (X1-2), and R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom, or a carbon number of 1 to 6. X represents a single bond, a substituted or unsubstituted alkylene group, a carbonyl group, an ether group, a group represented by the following formula (a), or a group represented by the following formula (b). M1 and m2 are each independently an integer of 0 to 4, m3 and m4 are each independently an integer of 0 to 5, m1 + m2 + m3 + m4 is 1 or more, and p represents an integer of 0 to 2. (If p is 2, each of the two Xs and the two m2 to m4 is independently selected.)


(In formula (2), Ry is a tetravalent group having 4 to 22 carbon atoms containing an alicyclic hydrocarbon ring structure, and does not contain an aromatic ring. Y is a residue of a single bond or a divalent aryl group. Q1 and q2 are each independently an integer of 1 to 4, and Ra and Rb are trifluoromethyl groups.) The proportion of the structural unit represented by the formula (1) to the sum of structural units represented by the formula (1) and a constitutional unit wherein the formula (2) is, according to claim 7 is 40 mol% or more Polyimide resin. The polyimide resin according to any one of claims 1 to 8, wherein the formula (1) is represented by the following formula (1-1).

(Rx in Formula (1-1) is the same as in Formula (1).) The laminated body in which the polyimide resin layer containing the polyimide resin of any one of Claims 1-9 is formed on a glass base material.