JP6558067B2 - Polyimide laminate and method for producing the same - Google Patents

Description

  The present invention relates to a polyimide laminate having a polyimide layer that contains a specific phosphorus compound, is inhibited from thermal decomposition in a temperature range of 500 ° C. or higher, and has excellent adhesion strength to a substrate.

  About equimolar amount of aromatic tetracarboxylic dianhydride mainly composed of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and aromatic diamine mainly composed of p-phenylenediamine is dimethyl A polyamic acid solution obtained by reacting at a relatively low temperature in an aprotic polar solvent such as acetamide is applied to a substrate, and the resulting coating film is dried by heating to a self-supporting film, and then a self-supporting film A polyimide film with particularly excellent properties such as heat resistance, chemical resistance, radiation resistance, electrical insulation, dimensional stability, and mechanical properties can be produced by further heat imidization after peeling off the substrate. Is known.

  In Patent Document 1, the carbon, oxygen, and nitrogen elements on the film surface, which are produced by the above-described method, have a specific ratio, and the phosphorus content in the entire film is 5 to 500 ppm. An improved polyimide film is disclosed. This polyimide film includes those obtained from 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine.

  Patent Document 2 proposes a polyimide film with improved mechanical strength, which is produced by the above method and contains an organic phosphorus compound in an amount of 0.5 to 5% by weight based on the polyimide. This polyimide may be composed of a very wide range of tetracarboxylic acid component and diamine component, and is preferably composed mainly of pyromellitic dianhydride and 4,4′-diaminodiphenyl ether. Those obtained from biphenyltetracarboxylic dianhydride and p-phenylenediamine are also included.

  Patent Document 3 discloses a polyamic obtained from a tetracarboxylic acid component containing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as a main component and a diamine component containing p-phenylenediamine as a main component. Disclosed is a polyimide laminate obtained by casting a polyamic acid solution composition containing an acid and a phosphorus compound on a substrate, heat-treating it, and forming a polyimide layer having a thickness of less than 50 μm on the substrate. ing. It is disclosed that a phosphoric acid ester is preferable as the phosphorus compound used here.

JP-A-8-143688 JP-A-2-28257 International Publication No. 2012/173204

  The present invention has excellent properties such as heat resistance, chemical resistance, radiation resistance, electrical insulation, dimensional stability, mechanical properties, etc. on the substrate, and thermal decomposition particularly in a temperature range of 500 ° C. to 650 ° C. It is an object of the present invention to provide a polyimide laminate having a highly heat-resistant polyimide layer that is further suppressed and has excellent adhesive strength with a substrate.

（式中、Ｒ¹は、炭素数が１〜６のアルキル基であり、Ｒ²はフェニル基又はシクロヘキシル基である。）

（式中、Ｒ³は、フェニル基又はシクロヘキシル基であり、Ｒ⁴は、シクロヘキシル基である。）

（式中、Ｒ⁵は、炭素−炭素不飽和結合を有する炭素数３〜１２の炭化水素基である。） The present invention relates to the following items.
1. A polyimide laminate having a polyimide layer obtained from a tetracarboxylic acid component containing 50 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and an aromatic diamine component on a substrate. And
A polyimide laminate, wherein the polyimide layer contains at least one phosphorus compound selected from the group consisting of phosphorus compounds represented by the following chemical formula (1), chemical formula (2), and chemical formula (3).

(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms, and R ² is a phenyl group or a cyclohexyl group.)

(In the formula, R ³ is a phenyl group or a cyclohexyl group, and R ⁴ is a cyclohexyl group.)

(Wherein, R ⁵ is a carbon - is a hydrocarbon group having 3 to 12 carbon atoms having a carbon-carbon unsaturated bond.)

2. Item 2. The polyimide laminate according to Item 1, wherein the aromatic diamine component contains 50 mol% or more of p-phenylenediamine, 4,4'-diaminodiphenyl ether, or a mixture thereof.

（式中、Ｒ¹は、炭素数が１〜６のアルキル基であり、Ｒ²はフェニル基又はシクロヘキシル基である。）

（式中、Ｒ³は、フェニル基又はシクロヘキシル基であり、Ｒ⁴は、シクロヘキシル基である。）

（式中、Ｒ⁵は、炭素−炭素不飽和結合を有する炭素数３〜１２の炭化水素基である。） 3. A method for producing a polyimide laminate having a polyimide layer on a substrate,
A polyamic acid obtained from a tetracarboxylic acid component containing 50 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and an aromatic diamine component, the following chemical formula (1), chemical formula (2 ) And a polyamic acid solution composition containing at least one phosphorus compound selected from the group consisting of phosphorus compounds represented by chemical formula (3) is cast on a base material, heat-treated, and then on the base material. A method for producing a polyimide laminate, comprising forming a polyimide layer.

(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms, and R ² is a phenyl group or a cyclohexyl group.)

(In the formula, R ³ is a phenyl group or a cyclohexyl group, and R ⁴ is a cyclohexyl group.)

(Wherein, R ⁵ is a carbon - is a hydrocarbon group having 3 to 12 carbon atoms having a carbon-carbon unsaturated bond.)

4). Item 4. The method for producing a polyimide laminate according to Item 3, wherein the aromatic diamine component contains 50 mol% or more of p-phenylenediamine, 4,4′-diaminodiphenyl ether, or a mixture thereof.
5. Item 5. The method for producing a polyimide laminate according to Item 3 or 4, wherein the maximum temperature in the heat treatment is 400 ° C to 550 ° C.
6). The polyimide laminated body obtained by the method in any one of said items 3-5.

  According to the present invention, the properties such as heat resistance, chemical resistance, radiation resistance, electrical insulation, dimensional stability, mechanical properties are excellent, and thermal decomposition is suppressed particularly in a temperature range of 500 ° C. to 650 ° C., Furthermore, the polyimide laminated body which has a highly heat-resistant polyimide layer excellent also in the adhesive strength with a base material on a base material can be provided. This polyimide laminate is suppressed from thermal decomposition at high temperature, and volatile components (outgas) are not generated even in a high temperature heat treatment process, or generation of volatile components (outgas) is suppressed. It is useful as a base substrate material.

  The polyimide laminate of the present invention has a polyimide layer comprising a tetracarboxylic acid component containing 50 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and an aromatic diamine component on a substrate. At least one selected from the group consisting of a specific phosphorus compound, that is, a phosphorus compound represented by the above chemical formula (1), chemical formula (2), and chemical formula (3) It contains the following phosphorus compound.

(Manufacturing method of polyimide laminate)
The polyimide laminate of the present invention includes, for example, a polyamic acid obtained from a tetracarboxylic acid component containing 50 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and an aromatic diamine component. A polyamic acid solution composition containing a specific phosphorus compound can be cast on a substrate and heat-treated.

  In the present invention, the polyamic acid has a tetracarboxylic acid component such as tetracarboxylic dianhydride and a diamine component in an approximately equimolar amount in a solvent at 100 ° C. or lower, preferably 80 ° C. or lower. By stirring and mixing at a relatively low temperature, a polyamic acid solution uniformly dissolved in a solvent can be suitably obtained. The phosphorus compound may be added before polymerization, and the tetracarboxylic dianhydride and diamine may be reacted in the presence of the phosphorus compound, or the phosphorus compound may be added to the polyamic acid solution obtained after polymerization. Good. The obtained polyamic acid solution can be used for forming a polyimide layer as it is or after adding a desired component if necessary.

  The polyamic acid used in the present invention contains 50 mol% or more of the tetracarboxylic acid component, preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 100 mol%, 3,3 ′, 4, 4'-biphenyltetracarboxylic dianhydride, preferably 50 mol% or more of the aromatic diamine component, more preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 100 mol%, p-phenylenediamine or 4,4′-diaminodiphenyl ether, or a mixture thereof. By using a polyamic acid having such a chemical composition, a polyimide layer having particularly excellent characteristics such as heat resistance, chemical resistance, radiation resistance, electrical insulation, dimensional stability, and mechanical properties can be obtained. In particular, a highly heat-resistant polyimide layer in which thermal decomposition is suppressed in a temperature range of 500 ° C. to 650 ° C. can be formed.

  In the present invention, the tetracarboxylic acid component that can be used in combination with 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride includes p-terphenyl-3,3 ″, 4,4 ″ -tetra Carboxylic dianhydride, 5,5 ′-(1,1′-biphenyl) -4,4′-diylbis-1,3-isobenzofurandione, naphthalene-1,4,5,8-tetracarboxylic dianhydride And naphthalene-2,3,6,7-tetracarboxylic dianhydride. Examples of other aromatic diamine components include 4,4'-diaminobiphenyl, 4,4 "-diamino-p-terphenyl, 4,4" '-diamino-p-quaterphenyl, and the like.

  The solvent used in the present invention may be any solvent as long as it can polymerize polyamic acid. For example, an aprotic polar solvent can be suitably used. The solvent used in the present invention is not particularly limited, but N, N-dilower such as N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide and the like. Alkyl carboxylamides, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, diglyme, m-cresol, hexa Preferable examples include methylphosphoramide, N-acetyl-2-pyrrolidone, hexamethylphosphoramide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, p-chlorophenol, and cyclohexanone. The solvent may be a mixture of two or more.

  In the present invention, acetic anhydride as an anhydrous agent, imidazole compounds such as 1,2-dimethylimidazole as imidization catalysts, heterocyclic compounds containing nitrogen atoms such as isoquinoline, basic compounds such as triethylamine and triethanolamine May be used within a range where the effects of the present invention can be obtained. However, when a dehydrating agent or an imidization catalyst is used, the stability of the polyamic acid solution decreases, it becomes difficult to cast to a base material, and thermal decomposition is further suppressed in a temperature range of 500 ° C to 650 ° C. Since it may be difficult to form a heat-resistant polyimide layer, it is preferable not to use them.

  In the present invention, water or a mixed solvent of water and an organic solvent, preferably a solvent containing water as a main component can also be suitably used. In that case, the organic solvent other than water is preferably used in a proportion of 50% by mass or less, preferably 30% by mass or less, more preferably 10% by mass or less in the total solvent. From the viewpoint of environmental adaptability, the content of the organic solvent is preferably less than 5% by mass, and particularly preferably an aqueous solvent that does not contain an organic solvent other than water.

  The organic solvent referred to here includes a tetracarboxylic acid component such as tetracarboxylic dianhydride, a diamine component, a polyimide precursor such as polyamic acid, and imidazoles (which will be described later, water or water as a main component). In general, imidazoles are added to the solvent.

  Examples of the organic solvent used in the solvent containing water as a main component include solvents such as the above-mentioned aprotic polar solvents, and in addition, N-methylcaprolactam, hexamethylphosphorotriamide, 1,2-dimethoxyethane. Bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, tetrahydrofuran, bis [2- (2-methoxyethoxy) ethyl] ether, 1,4-dioxane, diphenylether, diphenylsulfone, Tetramethylurea, anisole, phenol and the like can be mentioned.

  When using water or a solvent containing water as a main component, an imidazole is added to the solvent, and a tetracarboxylic dianhydride and a diamine are reacted in the presence of the imidazole to produce a polyamic acid aqueous solution composition. To do.

  As imidazoles used in the present invention, the solubility in water at 25 ° C. is preferably 0.1 g / L or more, particularly preferably 1 g / L or more. Here, the solubility in water at 25 ° C. means a limit amount (g) at which the substance is dissolved in 1 L (liter) of water at 25 ° C. This value can be easily searched by SciFinder (registered trademark) known as a search service based on a database such as a chemical abstract. Here, among the solubility under various conditions, the value at pH 7 calculated by Advanced Chemistry Development (ACD / Labs) Software V11.02 (Copyright 1994-2011 ACD / Labs) was adopted.

  Preferred examples of the imidazoles (compounds) used in the present invention include compounds represented by the following chemical formula (10).

（式中、Ｘ_１〜Ｘ_４は、それぞれ独立に、水素原子、或いは炭素数が１〜５のアルキル基を示す。）

_(Wherein, X 1 to X ₄ each independently represent a hydrogen atom, or carbon atoms show a 1-5 alkyl group.)

Furthermore, in the imidazoles of the chemical formula (10), X _{1 to} X ₄ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and at least two of X _{1 to} X ₄ However, imidazoles having 1 to 5 carbon atoms, that is, imidazoles having 2 or more alkyl groups as substituents are more preferable.

  Since imidazoles having two or more alkyl groups as substituents have high solubility in water, a polyimide precursor aqueous solution composition can be easily produced by using them. Examples of imidazoles include 1,2-dimethylimidazole (the solubility in water at 25 ° C. is 239 g / L, the same applies hereinafter), 2-ethyl-4-methylimidazole (1000 g / L), 4-ethyl-2-methylimidazole ( 1000 g / L) and 1-methyl-4-ethylimidazole (54 g / L) are preferred.

  In addition, the imidazole to be used may be one kind or a mixture of plural kinds.

  The amount of imidazoles used in the present invention is preferably 0.8 times equivalent or more, more preferably 1. with respect to the carboxyl group of the polyamic acid produced by the reaction of the raw material tetracarboxylic dianhydride and diamine. It is 0 times equivalent or more, More preferably, it is 1.2 times equivalent or more. If the amount of imidazole used is less than 0.8 equivalents relative to the carboxyl group of the polyamic acid, it may not be easy to obtain a uniformly dissolved polyimide precursor aqueous solution composition. Moreover, although the upper limit of the usage-amount of imidazoles is not specifically limited, Usually, it is less than 10 times equivalent, Preferably it is less than 5 times equivalent, More preferably, it is less than 3 times equivalent. If the amount of imidazole used is too large, it may become uneconomical and the storage stability of the polyimide precursor aqueous solution composition may be deteriorated.

  In the present invention, the double equivalent to the carboxyl group of the polyamic acid that defines the amount of imidazoles is the number (number of molecules) of imidazoles in one carboxyl group that forms the amic acid group of the polyamic acid. Indicates whether to use. Note that the number of carboxyl groups forming the amic acid group of the polyamic acid is calculated as forming two carboxyl groups per molecule of the starting tetracarboxylic acid component.

  Therefore, the amount of imidazoles used in the present invention is preferably 1.6 times mol or more, more preferably 2 times the amount of the raw material tetracarboxylic dianhydride (relative to the tetracarboxylic acid component of the polyamic acid). It is 0.0 times mol or more, More preferably, it is 2.4 times mol or more.

  The characteristics of the imidazoles used here are not only to increase the solubility in water by forming a salt with the carboxyl group of the polyamic acid (polyimide precursor) produced by the reaction of the raw material tetracarboxylic dianhydride and diamine. Furthermore, when the polyimide precursor is imidized (dehydration ring closure) to form a polyimide, it has an extremely high catalytic action. As a result, when the polyimide precursor aqueous solution composition of the present invention is used, for example, a polyimide having extremely high physical properties can be easily produced even by a heat treatment at a lower temperature and for a shorter time.

  As described above, in the present invention, approximately equimolar amounts of a tetracarboxylic acid component and a diamine component are reacted in a solvent at a relatively low temperature of 100 ° C. or lower, preferably 80 ° C. or lower, which can suppress the imidization reaction. As a result, a polyamic acid solution composition can be obtained. In the case of using water or a solvent containing water as a main component, an approximately equimolar amount of tetrahydrate in the presence of imidazoles, preferably in the presence of imidazoles having two or more alkyl groups as substituents. By reacting the carboxylic acid component and the diamine component, a polyamic acid aqueous solution composition can be obtained.

  Although it does not limit, reaction temperature is 25 to 100 degreeC normally, Preferably it is 40 to 80 degreeC, More preferably, it is 50 to 80 degreeC, Reaction time is about 0.1 to 24 hours, Preferably It is preferably about 2 to 12 hours. By setting the reaction temperature and reaction time within the above ranges, a high molecular weight polyamic acid solution composition can be efficiently obtained. The reaction can be carried out in an air atmosphere, but usually it is suitably carried out in an inert gas atmosphere, preferably in a nitrogen gas atmosphere.

  The molar ratio of the tetracarboxylic acid component to be reacted and the diamine component [tetracarboxylic acid component / diamine component] is preferably about 0.90 to 1.10, more preferably about 0.95 to 1.05.

  In the present invention, the polyamic acid solid content (polyimide conversion) concentration of the polyamic acid solution composition is not particularly limited, but is preferably 2 to 50% by mass, and preferably 5 to 40% by mass. The solution (rotational) viscosity of the polyamic acid solution composition is not particularly limited, but is preferably 1 to 3000 poise, preferably 5 to 2000 poise at 30 ° C.

  The molecular weight of the polyamic acid used in the present invention is not particularly limited, but usually a relatively high molecular weight in which the logarithmic viscosity (η) exceeds 2.0 dL / g in order to achieve sufficient characteristics of the resulting polyimide layer. The polyamic acid is preferably used. In the present invention, a polyamic acid having a lower molecular weight than that usually used, specifically, a relatively low molecular weight polyamic acid having a logarithmic viscosity of 2.0 dL / g or less is also preferably used, and the resulting polyimide layer is sufficient. Special characteristics can be achieved.

（式中、Ｒ¹は、炭素数が１〜６のアルキル基であり、Ｒ²はフェニル基又はシクロヘキシル基である。）

（式中、Ｒ³は、フェニル基又はシクロヘキシル基であり、Ｒ⁴は、シクロヘキシル基である。） In the present invention, the polyamic acid solution composition used for forming the polyimide layer contains a phosphorus compound. In particular, the polyamic acid solution composition preferably contains at least one phosphorus compound selected from the group consisting of phosphorus compounds represented by the following chemical formula (1) and chemical formula (2).

(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms, and R ² is a phenyl group or a cyclohexyl group.)

(In the formula, R ³ is a phenyl group or a cyclohexyl group, and R ⁴ is a cyclohexyl group.)

Preferred examples of R ^{1 in the} chemical formula (1) include a methyl group, an ethyl group, a propyl group, and a butyl group.
Among the phosphorus compounds represented by the chemical formula (1), bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, 1 , 4-bis (diphenylphosphino) butane, 1,4-bis (dicyclohexylphosphino) butane.
The phosphorus compound represented by the chemical formula (2) is specifically tricyclohexylphosphine, dicyclohexylphenylphosphine, or diphenylcyclohexylphosphine.

（式中、Ｒ⁵は、炭素−炭素不飽和結合を有する炭素数３〜１２の炭化水素基である。） In the present invention, a phosphoric acid ester represented by the following chemical formula (3) can also be used as the phosphorus compound.

(Wherein, R ⁵ is a carbon - is a hydrocarbon group having 3 to 12 carbon atoms having a carbon-carbon unsaturated bond.)

R ^{5 in the} chemical formula (3) is a reactive functional group, specifically a hydrocarbon group having 3 to 12 carbon atoms having a carbon-carbon unsaturated bond, and R ⁵ includes acryloyl group, methacryloyl group, acryloyl. Examples thereof include an oxyethyl group and a methacryloyloxyethyl group.
Particularly preferred phosphate esters represented by the chemical formula (3) include 2- (methacryloyloxy) ethyl phosphate and bis (2- (methacryloyloxy) ethyl phosphate).

  These phosphorus compounds may be used alone or in combination of two or more. Moreover, you may use together at least 1 sort (s) of the phosphorus compound represented by the said Chemical formula (1)-(3), and another phosphorus compound.

  The density | concentration of the phosphorus compound in a polyamic acid solution composition is 1-20 mol% as a density | concentration of a phosphorus atom with respect to 100 mol% of tetracarboxylic acid components, Preferably it is 1.5-15 mol%, More preferably, it is 2 A concentration corresponding to 10 mol% is preferred.

  When the concentration of the phosphorus compound in the polyamic acid solution composition is too small, it becomes difficult to sufficiently obtain the effect of suppressing thermal decomposition in the temperature range of 500 ° C to 650 ° C. On the other hand, if the concentration of the phosphorus compound is too high, a large amount of phosphorus remains in the polyimide layer, which may cause volatile components (outgas), which is not preferable.

  The phosphorus compound may be added to the polyamic acid solution before or after polymerization. That is, after a tetracarboxylic acid component and a diamine component are reacted in a solvent to obtain a polyamic acid solution composition, a phosphorus compound is added thereto to obtain a polyamic acid solution composition containing a phosphorus compound. A polyamic acid solution containing a phosphorus compound can also be obtained by adding a tetracarboxylic acid component, a diamine component, and a phosphorus compound to a solvent, and reacting the tetracarboxylic acid component and the diamine component in the solvent in the presence of the phosphorus compound. A composition can be obtained.

  In addition, the polyamic acid solution composition of this invention can also add another additive component, for example, a filler etc. as needed.

  In the present invention, a polyamic acid solution composition containing the polyamic acid and the phosphorus compound as described above is cast on a base material and heat-treated to form a polyimide layer on the base material.

  The substrate is not particularly limited as long as it can form a polyimide film on the surface thereof, but in the present invention, since it is heat-treated at an extremely high temperature, it can withstand the high temperature and expands due to heat. It is desirable to be made of a material having a small coefficient. The shape of the substrate is not particularly limited, but is usually a planar shape. Specifically, the base material may be, for example, a metal plate made of various metals, a ceramic plate made of various ceramics, or the like, but a glass plate can be preferably used particularly from the high temperature resistance and the linear expansion coefficient.

  The method for casting the polyamic acid solution composition onto the base material is not particularly limited, and conventionally known methods such as spin coating, screen printing, bar coater, and electrodeposition can be suitably used. .

  In the present invention, the substrate is formed of a material that does not substantially transmit gas, such as a glass plate. For this reason, when the layer (coating layer) of the polyamic acid solution composition cast on the base material is subjected to heat treatment, the volatile components (solvents, etc.) generated from the layer (coating layer) of the polyamic acid solution composition Water generated as a result of imidization cannot evaporate from the substrate surface, but evaporates only from the air (or other gas) surface of the other surface. In the production method of the present invention, the polyamic acid solution composition layer is not peeled off as a self-supporting film and is not heat-treated, and the volatile components evaporate only from one side until heat treatment at a high temperature at which imidization is completed. Heat treatment in the state to be.

  In the present invention, a polyamic acid solution composition is cast on a base material to form a polyamic acid solution composition film on the base material, and a laminate comprising the base material and the polyamic acid solution composition film After obtaining this, this is heat-treated to complete imidization, thereby forming a polyimide layer on the substrate. The heat treatment conditions are not particularly limited, but are at least more than 150 ° C. to less than 200 ° C., preferably the lower limit value is more than 155 ° C., more preferably more than 160 ° C., still more preferably more than 165 ° C., particularly preferably. Is a heat treatment in the temperature range of more than 170 ° C., preferably an upper limit of preferably less than 195 ° C., more preferably less than 190 ° C., and even more preferably less than 185 ° C. After that, heat treatment is preferably performed at a maximum temperature of 400 ° C to 550 ° C, preferably 430 ° C to 530 ° C, more preferably 460 ° C to 530 ° C. Note that the time for heat treatment at a temperature of 200 ° C. or higher (including the time for heat treatment at the maximum temperature) can be appropriately determined, and is not particularly limited.

  In this invention, a polyimide layer which consists of a base material and a polyimide layer can be obtained by forming a polyimide layer on a base material in this way.

(Polyimide laminate)
As described above, the polyimide laminate of the present invention is a polyimide layer comprising a tetracarboxylic acid component containing 50 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and an aromatic diamine component. Is a polyimide laminate in which a polyimide layer is selected from the group consisting of phosphorus compounds represented by the above chemical formula (1), chemical formula (2) and chemical formula (3). It contains a compound. Moreover, the polyimide laminated body of this invention is obtained by the above-mentioned manufacturing method.
The thickness of the polyimide layer of the polyimide laminate of the present invention is preferably less than 50 μm, preferably 30 μm or less, more preferably 20 μm or less. As the thickness of the polyimide layer exceeds the above range, a decomposition product derived from a phosphorus compound tends to remain, which may cause an excess volatile component (outgas) to be generated. Moreover, the formed polyimide layer is foamed and may not be used practically. The lower limit value of the thickness of the polyimide layer is not particularly limited, but is preferably 0.1 μm or more, preferably 1 μm or more, more preferably 2 μm or more.

  The polyimide layer of the polyimide laminate of the present invention is also excellent in adhesive strength with the substrate. For the adhesive strength between the substrate and the polyimide layer in the polyimide laminate, a load (90 ° peel strength) when the polyimide layer is peeled off at a peeling angle of 90 degrees and a peeling speed of 5 mm / min is an index. In the polyimide laminate of the present invention, the 90 ° peel strength when glass is used as the substrate is preferably 3 mN / mm or more, and more preferably 5 mN / mm or more.

(Suppression of thermal decomposition of polyimide laminate in the temperature range of 500 ° C to 650 ° C)
The polyimide layer of the polyimide laminate of the present invention has high heat resistance with thermal decomposition suppressed in the temperature range of 500 ° C to 650 ° C.

  Here, the fact that thermal decomposition is suppressed in the temperature range of 500 ° C. to 650 ° C. is indicated by 5% weight reduction temperature (° C.) when the polyimide layer is heat-treated as one index. When the 5% weight loss temperature shows a high value of 600 ° C. or higher, preferably 605 ° C. or higher, it indicates that thermal decomposition is suppressed to a higher temperature, and a temperature of 500 ° C. to 650 ° C. It can be seen that thermal decomposition in the region was suppressed. On the other hand, when this temperature is a low value of less than 600 ° C., it indicates that thermal decomposition occurs at a relatively low temperature, and thermal decomposition is suppressed in the temperature range of 500 ° C. to 650 ° C. No.

(Laminated body with other materials laminated)
The polyimide laminate of the present invention is particularly excellent in properties such as heat resistance, chemical resistance, radiation resistance, electrical insulation, dimensional stability, mechanical properties, and pyrolysis particularly in a temperature range of 500 ° C to 650 ° C. It is the polyimide laminated body in which the highly heat-resistant polyimide layer in which this was suppressed was formed. Therefore, for example, by sputtering the polyimide laminate, other materials such as ITO and amorphous silicon layers can be suitably laminated on the polyimide layer surface. And the laminated body which consists of a polyimide and another material can be obtained suitably by isolate | separating a base material from the laminated body which consists of the obtained base material, a polyimide, and another material.

  Such a laminate made of polyimide and another material can be suitably used for applications such as a flexible liquid crystal display, EL display, electronic paper, and thin film solar cell using a polyimide layer as a substrate.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to a following example.

Abbreviations of the compounds used in the following examples are as follows.
s-BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PPD: p-phenylenediamine NMP: N-methyl-2-pyrrolidone TPP: triphenyl phosphate DPPM: bis (diphenylphosphino) Methane DPPE: 1,2-bis (diphenylphosphino) ethane DPPP: 1,3-bis (diphenylphosphino) propane DPPPB: 1,4-bis (diphenylphosphino) butane DCHPB: 1,4-bis (dicyclohexylphos Fino) Butane DPCP: Diphenylcyclohexylphosphine TCHP: Tricyclohexylphosphine JPA-514: Mixture of 2- (methacryloyloxy) ethyl phosphate and bis (2- (methacryloyloxy) ethyl phosphate) (manufactured by Johoku Chemical Industry)

(Solid content concentration)
The solid content concentration of the polyamic acid solution is a value obtained by drying the polyamic acid solution at 350 ° C. for 30 minutes and obtaining the weight W ₁ before drying and the weight W ₂ after drying by the following formula.
Solid content concentration (% by weight) = W ₂ / W ₁ × 100

(Logarithmic viscosity of polyamic acid)
The logarithmic viscosity (η _inh ) of the polyamic acid was prepared by preparing a solution in which the polyamic acid solution was uniformly dissolved in N-methyl-2-pyrrolidone so that the polyamic acid concentration was 0.5 g / 100 ml of solvent. The solution viscosity with the solvent was measured at 30 ° C. and calculated by the following formula.

(Measurement of 5% weight loss temperature [TGA measurement method])
The polyimide layer is separated from the base material, and the temperature is raised from room temperature (25 ° C.) to 700 ° C. at 20 ° C./min using TG-DTA2000S (Mac Science). The decrease temperature was measured.
Since this 5% weight reduction is considered to be caused by the generation of volatile components (outgas) due to thermal decomposition, in the present invention, this 5% weight reduction temperature is used as a standard for thermal decomposition in the temperature range of 500 ° C to 650 ° C. evaluated.

(Appearance observation of polyimide layer)
When visual inspection of the appearance of the polyimide layer after heat treatment is performed and the transparency is almost unchanged compared to the polyimide layer to which no phosphorus compound is added under the same conditions, ○, when the transparency is partially reduced △, and X when the transparency was remarkably lowered.

(90 ° peel strength test)
The polyimide laminate was cut into a width of 10 mm, the load when the polyimide layer was peeled off at a peeling angle of 90 degrees and a peeling speed of 5 mm / min was measured, and the average value of the three samples was 90 ° peel strength.

[Reference Example 1]
To a glass reaction vessel having an internal volume of 500 mL equipped with a stirrer and a nitrogen gas introduction / discharge tube, 360 g of N-methyl-2-pyrrolidone was added as a solvent, and 24.1921 g (0.2237 mol) of PPD was added thereto. 65.8079 g (0.2237 mol) of s-BPDA was added and stirred at 50 ° C. to obtain a polyamic acid solution having a solid content concentration of 18.2% and a logarithmic viscosity of 0.65 dL / g.

[Comparative Example 1]
The polyamic acid solution obtained in Reference Example 1 was applied onto a glass plate by a spin coater, held at 120 ° C. for 10 minutes, 150 ° C. for 10 minutes, and 180 ° C. for 60 minutes, and further raised to 500 ° C. The heating process which warms was performed and the polyimide laminated body which formed the 10-micrometer-thick polyimide film on the glass plate was obtained. Table 5 shows the 5% weight loss temperature of the obtained polyimide layer and the evaluation results of the adhesion of the polyimide laminate.

[Comparative Example 2]
To the polyamic acid solution obtained in Reference Example 1, 4.5425 g of TPP was added as a phosphorus compound and stirred to obtain a polyamic acid solution composition. The amount of TPP added is 0.01386 mol, the amount of phosphorus atoms is 6.2 mol% with respect to 100 mol% of the tetracarboxylic acid component, and 5.0 wt% with respect to the total mass of the tetracarboxylic acid component and the diamine component.
Using this polyamic acid solution, a polyimide laminate was obtained in the same manner as in Comparative Example 1. Table 5 shows the 5% weight loss temperature of the obtained polyimide layer and the evaluation results of the adhesion of the polyimide laminate.

[Example 1]
The same operation as in Comparative Example 2 was performed except that 2.6653 g (0.00693 mol, 6.2 mol%, 3.0 wt%) of DPPM was added as a phosphorus compound instead of TPP. The evaluation results are shown in Table 2.

[Example 2]
It replaced with TPP and performed operation similar to the comparative example 2 except having added 2.6626g (0.00693 mol, 6.2 mol%, 3.1 wt%) of DPPE as a phosphorus compound. The evaluation results are shown in Table 2.

Example 3
The same operation as in Comparative Example 2 was performed except that 1.1140 g (0.002796 mol, 2.5 mol%, 1.2 wt%) of DPPE was added as a phosphorus compound instead of TPP. The evaluation results are shown in Table 2.

Example 4
It replaced with TPP and performed operation similar to the comparative example 2 except having added 2.8598 g (0.00693 mol, 6.2 mol%, 3.2 wt%) of DPPP as a phosphorus compound. The evaluation results are shown in Table 2.

Example 5
It replaced with TPP and performed operation similar to the comparative example 2 except having added 2.9570 g (0.00693 mol, 6.2 mol%, 3.3 wt%) of DPPB as a phosphorus compound. The evaluation results are shown in Table 2.

Example 6
Instead of TPP, 3.1248 g (0.00693 mol, 6.2 mol%, 3.5 wt%) of DCHPB as a phosphorus compound was added, and the same operation as in Comparative Example 2 was performed except that 36 g of cyclohexanone was added. The evaluation results are shown in Table 2.

Example 7
The same operation as in Comparative Example 2 was performed except that 1.8600 g (0.00693 mol, 6.2 mol%, 2.1 wt%) of DPCP was added as a phosphorus compound instead of TPP. The evaluation results are shown in Table 3.

Example 8
Instead of TPP, 1.9434 g (0.00693 mol, 6.2 mol%, 2.2 wt%) of TCHP was added as a phosphorus compound, and the same operation as in Comparative Example 2 was performed except that 36 g of cyclohexanone was added. The evaluation results are shown in Table 3.

Example 9
It replaced with TPP and performed operation similar to the comparative example 2 except adding 4.4688g (5.0 wt%) of JPA-514 as a phosphorus compound. The evaluation results are shown in Table 4.

Example 10
It replaced with TPP and performed operation similar to the comparative example 2 except having added 2.8331g (3.2 wt%) of JPA-514 as a phosphorus compound. The evaluation results are shown in Table 4.

Example 11
It replaced with TPP and performed operation similar to the comparative example 2 except having added 1.4415g (1.6 wt%) of JPA-514 as a phosphorus compound. The evaluation results are shown in Table 4.

Claims (5)

A polyimide laminate having a polyimide layer obtained from a tetracarboxylic acid component containing 50 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and an aromatic diamine component on a substrate. And
A polyimide laminate, wherein the polyimide layer contains at least one phosphorus compound selected from the group consisting of phosphorus compounds represented by the following chemical formula (1), chemical formula (2), and chemical formula (3).

(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms, and R ² is a phenyl group or a cyclohexyl group.)

(In the formula, R ³ is a phenyl group or a cyclohexyl group, and R ⁴ is a cyclohexyl group.)

(In the formula, R ⁵ represents an acryloyl group, a methacryloyl group, an acryloyloxyethyl group, or a methacryloyloxyethyl group .)   The polyimide laminate according to claim 1, wherein the aromatic diamine component contains 50 mol% or more of p-phenylenediamine, 4,4′-diaminodiphenyl ether, or a mixture thereof. A method for producing a polyimide laminate having a polyimide layer on a substrate,
A polyamic acid obtained from a tetracarboxylic acid component containing 50 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and an aromatic diamine component, the following chemical formula (1), chemical formula (2 ) And a polyamic acid solution composition containing at least one phosphorus compound selected from the group consisting of phosphorus compounds represented by chemical formula (3) is cast on a base material, heat-treated, and then on the base material. A method for producing a polyimide laminate, comprising forming a polyimide layer.

(In the formula, R ¹ is an alkyl group having 1 to 6 carbon atoms, and R ² is a phenyl group or a cyclohexyl group.)

(In the formula, R ³ is a phenyl group or a cyclohexyl group, and R ⁴ is a cyclohexyl group.)

(In the formula, R ⁵ represents an acryloyl group, a methacryloyl group, an acryloyloxyethyl group, or a methacryloyloxyethyl group .)   The method for producing a polyimide laminate according to claim 3, wherein the aromatic diamine component contains 50 mol% or more of p-phenylenediamine, 4,4'-diaminodiphenyl ether, or a mixture thereof.   The maximum temperature in heat processing is 400 to 550 degreeC, The manufacturing method of the polyimide laminated body of Claim 3 or 4 characterized by the above-mentioned.