The polymer includes a first structural unit represented by formula (1), a second structural unit represented by formula (2), and a third structural unit represented by formula (3). R.sup.1, R.sup.2, R.sup.10 and R.sup.11 each independently represent a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a nitro group or a cyano group; R.sup.3A, R.sup.3B R.sup.4A and R.sup.4B each independently represent a methylene group or an alkylene group having 2 to 4 carbon atoms; Z.sup.A to Z.sup.D each independently represent —O— or —S—; and L represents a divalent group represented by formula (3-1) or (3-2), wherein R.sup.a represents a divalent alicyclic hydrocarbon group having 5 to 30 ring atoms or a divalent fluorinated alicyclic hydrocarbon group having 5 to 30 ring atoms.

##STR00001##

The polymer includes a first structural unit represented by formula (1), a second structural unit represented by formula (2), and a third structural unit represented by formula (3). R.sup.1, R.sup.2, R.sup.10 and R.sup.11 each independently represent a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a nitro group or a cyano group; R.sup.3A, R.sup.3B R.sup.4A and R.sup.4B each independently represent a methylene group or an alkylene group having 2 to 4 carbon atoms; Z.sup.A to Z.sup.D each independently represent —O— or —S—; and L represents a divalent group represented by formula (3-1) or (3-2), wherein R.sup.a represents a divalent alicyclic hydrocarbon group having 5 to 30 ring atoms or a divalent fluorinated alicyclic hydrocarbon group having 5 to 30 ring atoms.

##STR00001##

The present disclosure relates to a polycarbonate and a preparation method thereof, which has a novel structure with an improvement in weather resistance and refractive index, while having excellent mechanical properties.

##STR00001##

A method for producing an oligomeric polyethylene terephthalate (PET) substrate for use in a recycled PET (rPET) manufacturing process comprises adding recycled bis-hydroxylethyleneterephthalate (rBHET) or a higher molecular weight oligomer derived from rBHET and water to a reaction zone and reacting the rBHET and water in the reaction zone to produce an oligomeric PET substrate represented by the Formula (I): wherein R1 is a carboxyl end group or a hydroxyl end group, R2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation (Dp).

A medical device capable of transmitting a radiofrequency signal to and/or receiving a radiofrequency signal from an external device is provided. The medical device comprises at least one component that contains a polymer composition that exhibits a dielectric constant of about 6 or less at a frequency of 2 GHz, wherein the polymer composition includes a liquid crystalline polymer.

A medical device capable of transmitting a radiofrequency signal to and/or receiving a radiofrequency signal from an external device is provided. The medical device comprises at least one component that contains a polymer composition that exhibits a dielectric constant of about 6 or less at a frequency of 2 GHz, wherein the polymer composition includes a liquid crystalline polymer.

The present invention provides an aromatic polyester having several operative functional groups and a method for producing same. An aromatic polyester comprising a polycarboxylic acid component and a polyhydric alcohol component as a copolymerization component, wherein the aromatic polyester comprises a polycarboxylic acid component having an operative functional group by 50 mol % or more when a total amount of the polycarboxylic acid component is taken as 100 mol %, and the aromatic polyester comprises an aromatic polyhydric alcohol component by 50 mol % or more when a total amount of the polyhydric alcohol component is taken as 100 mol %.

To provide an epoxy resin composition that exhibits excellent low-dielectric properties and that is excellent in copper foil peel strength and interlayer cohesion strength in a printed-wiring board application, as well as an active ester resin that provides the epoxy resin composition. An active ester resin having a polyaryloxy unit containing a dicyclopentenyl group and represented by the following formula (1), and a polyarylcarbonyl unit. Here, R.sup.1 represents a hydrocarbon group having 1 to 8 carbon atoms, R.sup.2 represents a hydrogen atom, or formula (1a) or formula (1b), and at least one R.sup.2 is formula (1a) or formula (1b); and n represents a number of repetitions of 1 to 5.

##STR00001##

To provide an epoxy resin composition that exhibits excellent low-dielectric properties and that is excellent in copper foil peel strength and interlayer cohesion strength in a printed-wiring board application, as well as an active ester resin that provides the epoxy resin composition. An active ester resin having a polyaryloxy unit containing a dicyclopentenyl group and represented by the following formula (1), and a polyarylcarbonyl unit. Here, R.sup.1 represents a hydrocarbon group having 1 to 8 carbon atoms, R.sup.2 represents a hydrogen atom, or formula (1a) or formula (1b), and at least one R.sup.2 is formula (1a) or formula (1b); and n represents a number of repetitions of 1 to 5.

##STR00001##

A method for producing an oligomeric PET substrate for use in a rPET manufacturing process comprises reacting recycled bis-hydroxylethyleneterephthalate (rBHET) or a higher molecular weight oligomer derived from rBHET, with PTA to produce an oligomeric PET substrate represented by Formula (I), wherein R.sub.1 is a carboxyl end group or a hydroxyl end group, R.sub.2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation.