The present invention has the effect of making it possible to produce 1,1,1-trifluoro-2,2-bisarylethane efficiently by a simple procedure by condensing a mixture of fluoral and hydrogen fluoride with an aryl compound under anhydrous conditions. The purity of the 1,1, 1-trifluoro-2, 2-bisarylethane obtained can be raised by a simple purification method such as crystallization or distillation. The obtained 1,1,1-trifluoro-2,2-bisarylethane can be increased in purity by a simple purification method such as crystallization operation or distillation.

The present invention has the effect of making it possible to produce 1,1,1-trifluoro-2,2-bisarylethane efficiently by a simple procedure by condensing a mixture of fluoral and hydrogen fluoride with an aryl compound under anhydrous conditions. The purity of the 1,1, 1-trifluoro-2, 2-bisarylethane obtained can be raised by a simple purification method such as crystallization or distillation. The obtained 1,1,1-trifluoro-2,2-bisarylethane can be increased in purity by a simple purification method such as crystallization operation or distillation.

A polyimide which is obtained by a reaction of an aromatic diamine having a 1,1,1-trifluoro-2,2-ethanediyl group (—C(CF.sub.3)H—), as a linkage skeleton, with a tetracarboxylic dianhydride is easily dissolved in an organic solvent and exhibits excellent film forming properties. In addition, the thus-obtained polyimide can be used for an optical film and a display device.

A polyimide which is obtained by a reaction of an aromatic diamine having a 1,1,1-trifluoro-2,2-ethanediyl group (—C(CF.sub.3)H—), as a linkage skeleton, with a tetracarboxylic dianhydride is easily dissolved in an organic solvent and exhibits excellent film forming properties. In addition, the thus-obtained polyimide can be used for an optical film and a display device.

A bisphenol composition includes 95% or more by mass of a bisphenol and 200 mass ppm or more of a compound represented by the following general formula (II):

##STR00001##

In formula (II), R.sup.21 and R.sup.22 denote a methyl group or a hydrogen atom; R.sup.22 is a methyl group when R.sup.21 is a hydrogen atom; R.sup.22 is a hydrogen atom when R.sup.21 is a methyl group; R.sup.23 to R.sup.25 independently denote a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and R.sup.23, R.sup.24, and R.sup.25 may be bonded or cross-linked between two of the groups. A method for producing a polycarbonate resin using the bisphenol composition is also described.

A bisphenol composition includes 95% or more by mass of a bisphenol and 200 mass ppm or more of a compound represented by the following general formula (II):

##STR00001##

In formula (II), R.sup.21 and R.sup.22 denote a methyl group or a hydrogen atom; R.sup.22 is a methyl group when R.sup.21 is a hydrogen atom; R.sup.22 is a hydrogen atom when R.sup.21 is a methyl group; R.sup.23 to R.sup.25 independently denote a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and R.sup.23, R.sup.24, and R.sup.25 may be bonded or cross-linked between two of the groups. A method for producing a polycarbonate resin using the bisphenol composition is also described.

A bisphenol composition includes 95% or more by mass of a bisphenol and 200 mass ppm or more of a compound represented by the following general formula (II):

##STR00001##

In formula (II), R.sup.21 and R.sup.22 denote a methyl group or a hydrogen atom; R.sup.22 is a methyl group when R.sup.21 is a hydrogen atom; R.sup.22 is a hydrogen atom when R.sup.21 is a methyl group; R.sup.23 to R.sup.25 independently denote a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and R.sup.23, R.sup.24, and R.sup.25 may be bonded or cross-linked between two of the groups. A method for producing a polycarbonate resin using the bisphenol composition is also described.

A bis-propylcatechol having a structure represented by formula (1):

##STR00001## wherein R.sup.1 is a divalent aliphatic hydrocarbon group having two or more carbon atoms or a divalent aromatic hydrocarbon group.

A bis-propylcatechol having a structure represented by formula (1):

##STR00001## wherein R.sup.1 is a divalent aliphatic hydrocarbon group having two or more carbon atoms or a divalent aromatic hydrocarbon group.

A process for producing bisphenol-A comprises reacting acetone and phenol in the presence of a catalyst system comprising an acidic heterogeneous catalyst and a catalyst promoter comprising at least one organic sulfur-containing compound to produce a reaction effluent comprising bisphenol-A, water, unreacted acetone, unreacted phenol and at least part of the catalyst promoter. At least part of the reaction effluent is distilled to remove water, catalyst promoter and unreacted acetone, and leave a residual stream containing bisphenol A. At least part of the residual stream is then contacted with a basic anion exchange resin to produce a purified stream, from which bisphenol-A is recovered.