Low-birefringent organic optical component and a spirobiindan polymer

A polycarbonate comprising a structural unit derived from the dihydroxy compound represented by formula (5);

• wherein R.sub.1 represents an optionally substituted straight, branched or cyclic alkyl group, an optionally substituted straight, branched or cyclic alkoxy group, nitro group, or a halogen atom;
• R.sub.2 is independently hydrogen atom or methyl group;
• k is an integer of 0 to 3;
• l and m are independently an integer of 0 to 20;
• and l+m is not zero.

An acrylate compound represented by formula (6);

• ##STR184## wherein R.sub.1 represents an optionally substituted straight, branched or cyclic alkyl group, an optionally substituted straight, branched or cyclic alkoxy group, nitro group, or a halogen atom;
• R.sub.2 is independently hydrogen atom or methyl group;
• R.sub.3 is independently hydrogen atom or methyl group;
• k is an integer of 0 to 3;
• l and m are independently an integer of 0 to 20;
• and l+m may be zero.

A polyester comprising the structural unit represented by formula (7);

• ##STR185## wherein R.sub.1 represents an optionally substituted straight, branched or cyclic alkyl group, an optionally substituted straight, branched or cyclic alkoxy group, nitro group, or a halogen atom;
• R.sub.2 is independently hydrogen atom or methyl group;
• R.sub.4 is an alkylene, aralkylene or arylene group;
• k is an integer of 0 to 3;
• l and m are independently an integer of 0 to 20;
• and l+m is not zero.

A polyurethane comprising the structural unit represented by formula (8);

• ##STR186## wherein R.sub.1 represents an optionally substituted straight, branched or cyclic alkyl group, an optionally substituted straight, branched or cyclic alkoxy group, nitro group, or a halogen atom;
• R.sub.2 is independently hydrogen atom or methyl group;
• R.sub.5 is a bivalent organic group;
• k is an integer of 0 to 3;
• l and m are independently an integer of 0 to 20;
• and l+m is not 0.

A vinyl ether compound represented by formula (11);

• ##STR187## wherein R.sub.1 represents an optionally substituted straight, branched or cyclic alkyl group, an optionally substituted straight, branched or cyclic alkoxy group, nitro group, or a halogen atom;
• R.sub.6 is a hydrogen atom or CH.sub.2 .dbd.CH--O--R.sub.7 -group wherein R.sub.7 represents an alkylene group with 1 to 12 carbons or 2-hydroxytrimethylene group;
• two R.sub.6 s may be the same as or different although they are not simultaneously hydrogen atom;
• and k is an integer of 0 to 3.

A copolymeric polycarbonate comprising the structural unit represented by formula (12);

• ##STR188## wherein R.sub.1 represents an optionally substituted straight, branched or cyclic alkyl group, an optionally substituted straight, branched or cyclic alkoxy group, nitro group, or a halogen atom;
• R.sub.2 is independently hydrogen atom or methyl group;
• R.sub.8 is an alkyl group;
• k is an integer of 0 to 3;
• l and m are independently an integer of 0 to 20;
• q and r are independently an integer of 0 to 20;
• and s is an integer of 0 to 4.

A fluorine-containing polyimide comprising the structural unit represented by formula (15);

• ##STR189## wherein Ar.sub.3 is the group represented by formula (m), (n), (o) or (p);
• ##STR190## wherein v is an integer equal to or higher than 1;
• ##STR191## wherein W is a direct bond, --O--, --S--, --CO--, --SO.sub.2 --, --C(CH.sub.3).sub.2 -- or --C(CF.sub.3).sub.2 --;
• T is fluorine atom, or a fluoroalkyl or fluoroalkyoxy group;
• T may be the same or different;
• k is an integer of 0 to 3, although W is --C(CF.sub.3).sub.2 -- when k is zero;
• ##STR192## wherein W, T and k are as defined above and s is an integer of 0 to 4, although W is --C(CF.sub.3).sub.2 -- when k and s are simultaneously zero;
• ##STR193##

A polyimide with a logarithmic viscosity of at least 0.01 dL/g and up to 3.00 dL/g, comprising the structural unit represented by formula (17);

• ##STR196## wherein Z is a monvalent group selected from an alkyl or alkoxy group with 1 to 3 carbons;
• phenyl, phenoxy, benzyl or naphthyl group;
• or the group represented by general formula (a), (b) or (w);
• ##STR197## wherein Q is a monvalent group selected from a halogen atom, an alkyl or alkoxy group with 1 to 3 carbons, or the group represented by an halogenated or alkoxy group wherein hydrogen atoms are partially or completely substituted by halogen atoms;
• Q may be the same or different;
• u is an integer of 0 to 5, and v is an integer of 0 to 4;
• Ar.sub.1 is a tetravalent group represented by formula (c), (d) or (e);
• ##STR198## wherein Q and k are as defined above;
• k is an integer of 0 to 3 and s is an integer of 0 to 4, although the total of k and s is at least 1.

A polyamide with a logarithmic viscosity of at least 0.01 dL/g up to 3.00 dL/g, comprising the structural unit represented by formula (18);

• ##STR199## wherein Ar.sub.2 is a bivalent group represented by formula (h), (i) or (j);
• ##STR200## wherein Q is a monvalent group selected from a halogen atom, an alkyl or alkoxy group with 1 to 3 carbons, or the group represented by a halogenated or alkoxy group wherein hydrogen atoms are partially or completely substituted by halogen atoms;
• Q may be the same or different;
• k is an integer of 0 to 3 and s is an integer of 0 to 4 although the total of k and s is at least 1;
• K is a bivalent group selected from a direct bond, --CO--, --S--, --SO.sub.2 --, --CH.sub.2 --, --C(CH.sub.3).sub.2 --, --C(CF.sub.3).sub.2 -- or the group represented by formula (f), (g), (k) or (l);
• ##STR201## wherein Q and s are defined above, L is a bivalent group selected from a direct bond, --CO--, --S-- or --O--;
• M is bivalent group selected from a direct bond, --CO--, --S--, --O--, --SO.sub.2 --, --CH.sub.2 --, --C(CH.sub.3).sub.2 -- or --C(CF.sub.3).sub.2 --;
• and Z is a monvalent group selected from an alkyl or alkoxy group with 1 to 3 carbons;
• phenyl, phenoxy, benzyl or naphthyl group;
• or the group represented by general formula (a), (b) or (w);
• ##STR202## wherein Q is defined above;
• u is an integer of 0 to 5;
• and v is an integer of 0 to 4.