Aqueous polyimide precursor solution composition and method for producing aqueous polyimide precursor solution

Abstract

An aqueous polyimide precursor solution composition in which a polyamic acid which is obtained by reacting a tetracarboxylic acid component and a diamine component is dissolved in an aqueous solvent together with an imidazole in an amount of 1.6 moles or more per mole of the tetracarboxylic acid component of the polyamic acid.

1 . An aqueous polyimide precursor solution composition, wherein
 a polyamic acid, which is formed by the reaction of a tetracarboxylic acid component and a diamine component, and consists of a repeating unit represented by the following formula (1), is dissolved in an aqueous solvent together with an imidazole in an amount of 1.6 mole or more per mole of the tetracarboxylic acid component of the polyamic acid.   
       
         
           
           
               
               
           
         
       
       wherein
 A represents at least one selected from the group consisting of a tetravalent group of an aromatic tetracarboxylic acid containing no fluorine group, from which carboxyl groups have been removed, a tetravalent group of an aliphatic tetracarboxylic acid, from which carboxyl groups have been removed, and a tetravalent group of an aromatic tetracarboxylic acid containing a fluorine group, from which carboxyl groups have been removed, and 
 B represents at least one selected from the group consisting of a divalent group of an aromatic diamine containing no fluorine group and having a solubility in water at 25° C. of 0.1 g/L or more, from which amino groups have been removed, a divalent group of an aliphatic diamine having a molecular weight of 500 or less, from which amino groups have been removed, and a divalent group of an aromatic diamine containing a fluorine group, from which amino groups have been removed, 
 
       with the proviso that
 not less than 50 mol % of A is a tetravalent group of an aliphatic tetracarboxylic acid, from which carboxyl groups have been removed, and/or a tetravalent group of an aromatic tetracarboxylic acid containing a fluorine group, from which carboxyl groups have been removed, and not more than 50 mol %, including 0 mol %, of A is a tetravalent group of an aromatic tetracarboxylic acid containing no fluorine group, from which carboxyl groups have been removed, and/or 
 not less than 50 mol % of B is a divalent group of an aliphatic diamine having a molecular weight of 500 or less, from which amino groups have been removed, and/or a divalent group of an aromatic diamine containing a fluorine group, from which amino groups have been removed, and not more than 50 mol %, including 0 mol %, of B is a divalent group of an aromatic diamine containing no fluorine group and having a solubility in water at 25° C. of 0.1 g/L or more, from which amino groups have been removed. 
 
     
     
         2 . The aqueous polyimide precursor solution composition of  claim 1 , wherein the imidazole is selected from the group consisting of 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 4-ethyl-2-methylimidazole, and 1-methyl-4-ethylimidazole. 
     
     
         3 . The aqueous polyimide precursor solution of  claim 1 , wherein the aqueous polyimide precursor solution composition has an organic solvent content of less than 5 wt %. 
     
     
         4 . The aqueous polyimide precursor solution composition of  claim 3 , wherein the aqueous polyimide precursor solution composition contains substantially no organic solvent. 
     
     
         5 . A polyimide produced by heating the aqueous polyimide precursor solution composition of  claim 1 . 
     
     
         6 . The polyimide of  claim 5 , wherein the polyimide has a light transmittance at 400 nm of 60% or more when the polyimide is formed into a film having a thickness of 10 μm. 
     
     
         7 . The polyimide of  claim 5 , wherein the polyimide has a total light transmittance of 80% or more when the polyimide is formed into a film having a thickness of 10 μm. 
     
     
         8 . A polyimide film obtained from the aqueous polyimide precursor solution composition of  claim 1 , wherein the polyimide film has a light transmittance at 400 nm of 60% or more in terms of 10 μm of film thickness. 
     
     
         9 . A polyimide film obtained from the aqueous polyimide precursor solution composition of  claim 1 , wherein the polyimide film has a total light transmittance of 80% or more in terms of 10 μm of film thickness. 
     
     
         10 . A method for producing an aqueous polyimide precursor solution composition, comprising
 reacting a tetracarboxylic acid component, which comprises an aliphatic tetracarboxylic dianhydride and/or an aromatic tetracarboxylic dianhydride containing a fluorine group in an amount of not less than 50 mol % and comprises an aromatic tetracarboxylic dianhydride containing no fluorine group in an amount of not more than 50 mol %, or alternatively, does not comprise an aromatic tetracarboxylic dianhydride containing no fluorine group, and a diamine component, which comprises an aliphatic diamine having a molecular weight of 500 or less and/or an aromatic diamine containing a fluorine group in an amount of not less than 50 mol % and comprises an aromatic diamine containing no fluorine group and having a solubility in water at 25° C. of 0.1 g/L or more in an amount of not more than 50 mol %, or alternatively, does not comprise an aromatic diamine containing no fluorine group and having a solubility in water at 25° C. of 0.1 g/L or more, in the presence of an imidazole using water as a reaction solvent to provide an aqueous polyimide precursor solution composition.   
     
     
         11 . The method for producing an aqueous polyimide precursor solution composition of  claim 10 , wherein the amount of the imidazole used is 1.6 mole or more per mole of the tetracarboxylic dianhydride. 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . An electrical device, an electronic device, an optical device, a display device, a touch panel, a solar battery, or an LED lighting device comprising the polyimide of  claim 5 . 
     
     
         15 . A polyimide precursor resin composition for flexible device substrates, wherein
 a polyamic acid, which is formed by the reaction of a tetracarboxylic acid component and a diamine component, and consists of a repeating unit represented by the following formula (1), is dissolved in an aqueous solvent together with an imidazole in an amount of 1.6 mole or more per mole of the tetracarboxylic acid component of the polyamic acid.   
       
         
           
           
               
               
           
         
       
       wherein
 A represents at least one selected from the group consisting of a tetravalent group of an aromatic tetracarboxylic acid containing no fluorine group, from which carboxyl groups have been removed, a tetravalent group of an aliphatic tetracarboxylic acid, from which carboxyl groups have been removed, and a tetravalent group of an aromatic tetracarboxylic acid containing a fluorine group, from which carboxyl groups have been removed, and 
 B represents at least one selected from the group consisting of a divalent group of an aromatic diamine containing no fluorine group and having a solubility in water at 25° C. of 0.1 g/L or more, from which amino groups have been removed, a divalent group of an aliphatic diamine having a molecular weight of 500 or less, from which amino groups have been removed, and a divalent group of an aromatic diamine containing a fluorine group, from which amino groups have been removed, 
 
       with the proviso that
 not less than 50 mol % of A is a tetravalent group of an aliphatic tetracarboxylic acid, from which carboxyl groups have been removed, and/or a tetravalent group of an aromatic tetracarboxylic acid containing a fluorine group, from which carboxyl groups have been removed, and not more than 50 mol %, including 0 mol %, of A is a tetravalent group of an aromatic tetracarboxylic acid containing no fluorine group, from which carboxyl groups have been removed, and/or 
 not less than 50 mol % of B is a divalent group of an aliphatic diamine having a molecular weight of 500 or less, from which amino groups have been removed, and/or a divalent group of an aromatic diamine containing a fluorine group, from which amino groups have been removed, and not more than 50 mol %, including 0 mol %, of B is a divalent group of an aromatic diamine containing no fluorine group and having a solubility in water at 25° C. of 0.1 g/L or more, from which amino groups have been removed. 
 
     
     
         16 . A method for producing a flexible device which is a display device or a light-receiving device, comprising steps of:
 applying the polyimide precursor resin composition for flexible device substrates of  claim 15  onto a carrier substrate, and then heating the composition to form a solid polyimide resin film;   forming a circuit on the polyimide resin film; and   separating the polyimide resin film on which the circuit is formed from the carrier substrate.   
     
     
         17 . A flexible device produced by the method for producing a flexible device of  claim 16 , wherein the flexible device is a display device or a light-receiving device.