The present invention is related to the application of solid polymers or copolymers prepared from monomers having in their structure a polycyclic aromatic ring, an aromatic ring of the type of naphthalene, or polyesters, polyethers, polyamides or polyvynil derivatives having naphthalene units in their structure, in the hydrotreatment or hydrocracking of heavy hydrocarbons, such as heavy or extra-heavy crude oils or residues from the distillation of petroleum; these polymers or copolymers may be supported, anchored or in a physical mixture with metallic oxides such as alumina, silica, titania or kaolin, and they have an application as heterogeneous hydrogen donors in reactions of hydrotreatment or hydrocracking of heavy or extra-heavy crude oils, residues from the distillation of petroleum and cuts and streams deived from this distillation. These solid polymers or copolymers operate in the presence of hydrogen or methane-rich gas. These hydrogen donor polymers, being solid, may be recovered from the reaction mixture to be reused and have a thermal stability that allows for their use in reactions at temperatures above 450 C. These heterogeneous hydrogen donors improve the physical properties of crude oils, such as API gravity, viscosity, and distillates yield, inhibiting the formation of coke.

According to one embodiment, a polyester resin is provided, which includes a structural unit derived from a compound represented by general formula (1), a structural unit derived from a compound represented by general formula (2), and a structural unit derived from a dicarboxylic acid or a derivative thereof.

##STR00001##

It is an object of this invention to provide an optical member that is able to cut ultraviolet rays without employing means such as addition of an ultraviolet absorber to the resin, using an ultraviolet cut filter or using ultraviolet absorption coating, as well as a thermoplastic resin to be used for the optical member. The thermoplastic resin of the invention comprises a spatial structural component unit, wherein the spatial structural component unit includes four or more aromatic groups selected from the group consisting of monocyclic aromatic groups and fused polycyclic aromatic groups, the spatial structural component unit has three or more monocyclic aromatic groups and/or heterocyclic aromatic groups in a conjugated structure, or one or more monocyclic aromatic groups and one or more fused polycyclic aromatic groups in a conjugated structure, or two or more fused polycyclic aromatic groups in a conjugated structure, and in a 0.1 mass % dichloromethane solution, the light transmittance at a wavelength of 355 nm is lower than 20% and the light transmittance at a wavelength of 500 nm is 90% or higher.

It is an object of this invention to provide an optical member that is able to cut ultraviolet rays without employing means such as addition of an ultraviolet absorber to the resin, using an ultraviolet cut filter or using ultraviolet absorption coating, as well as a thermoplastic resin to be used for the optical member. The thermoplastic resin of the invention comprises a spatial structural component unit, wherein the spatial structural component unit includes four or more aromatic groups selected from the group consisting of monocyclic aromatic groups and fused polycyclic aromatic groups, the spatial structural component unit has three or more monocyclic aromatic groups and/or heterocyclic aromatic groups in a conjugated structure, or one or more monocyclic aromatic groups and one or more fused polycyclic aromatic groups in a conjugated structure, or two or more fused polycyclic aromatic groups in a conjugated structure, and in a 0.1 mass % dichloromethane solution, the light transmittance at a wavelength of 355 nm is lower than 20% and the light transmittance at a wavelength of 500 nm is 90% or higher.

Provided are a novel ultraviolet absorber that has an excellent absorbing property for UV-A or UV-B, furthermore specifically absorbs only ultraviolet ray at a specific wavelength, and is capable of being used for general purposes, and an ultraviolet absorbing resin excellent in bleed-out resistance in addition to the characteristics described above. The ultraviolet absorber is a fluorene compound represented by the general formula (1) or a resin comprising the fluorene compound as a constituent unit.

Provided are a novel ultraviolet absorber that has an excellent absorbing property for UV-A or UV-B, furthermore specifically absorbs only ultraviolet ray at a specific wavelength, and is capable of being used for general purposes, and an ultraviolet absorbing resin excellent in bleed-out resistance in addition to the characteristics described above. The ultraviolet absorber is a fluorene compound represented by the general formula (1) or a resin comprising the fluorene compound as a constituent unit.

Provided are a retardation film that has a high heat resistance, has excellent formability and handleability even in a single-layer structure, has a negative thickness-direction retardation Rth value, and is suitable as a negative A-plate or a positive C-plate and a method for producing the film. The retardation film is formed of a stretched film of a polyester resin, contains a unit (A1) represented by the formula (1) as a diol unit (A) and a unit (B1) represented by the formula (2a) or (2b) as a dicarboxylic acid unit (B), and is a negative A-plate or a positive C-plate. ##STR00001## In the formulae, Z.sup.1 and Z.sup.2 represent an aromatic hydrocarbon ring, R.sup.1, R.sup.2a, R.sup.2b, R.sup.3a and R.sup.3b represent a substituent, k, p1 and p2 denotes an integer of 0 to 8, q denotes an integer of 0 to 4, m1, m2, n1 and n2 denotes an integer of not less than 0, A.sup.1a and A.sup.1b represents an alkylene group, and A.sup.2a, A.sup.2b and A.sup.3 represents a divalent hydrocarbon group.

Provided are a retardation film that has a high heat resistance, has excellent formability and handleability even in a single-layer structure, has a negative thickness-direction retardation Rth value, and is suitable as a negative A-plate or a positive C-plate and a method for producing the film. The retardation film is formed of a stretched film of a polyester resin, contains a unit (A1) represented by the formula (1) as a diol unit (A) and a unit (B1) represented by the formula (2a) or (2b) as a dicarboxylic acid unit (B), and is a negative A-plate or a positive C-plate. ##STR00001## In the formulae, Z.sup.1 and Z.sup.2 represent an aromatic hydrocarbon ring, R.sup.1, R.sup.2a, R.sup.2b, R.sup.3a and R.sup.3b represent a substituent, k, p1 and p2 denotes an integer of 0 to 8, q denotes an integer of 0 to 4, m1, m2, n1 and n2 denotes an integer of not less than 0, A.sup.1a and A.sup.1b represents an alkylene group, and A.sup.2a, A.sup.2b and A.sup.3 represents a divalent hydrocarbon group.

A thermoplastic resin, includes a constituent unit (A) derived from a monomer represented by the following general formula (1):

##STR00001## wherein R.sub.1 each independently represents an alkylene group containing 1 to 4 carbon atoms, R.sub.2 each independently represents an alkyl group containing 1 to 6 carbon atoms, an aryl group containing 6 to 18 carbon atoms or a halogen atom, n each independently represents 0 or an integer of 1 to 4, and R.sub.3 each independently represents a hydrogen atom, an alkyl group containing 1 to 6 carbon atoms or an alkenyl group containing 2 to 4 carbon atoms.

A thermoplastic resin, includes a constituent unit (A) derived from a monomer represented by the following general formula (1):

##STR00001## wherein R.sub.1 each independently represents an alkylene group containing 1 to 4 carbon atoms, R.sub.2 each independently represents an alkyl group containing 1 to 6 carbon atoms, an aryl group containing 6 to 18 carbon atoms or a halogen atom, n each independently represents 0 or an integer of 1 to 4, and R.sub.3 each independently represents a hydrogen atom, an alkyl group containing 1 to 6 carbon atoms or an alkenyl group containing 2 to 4 carbon atoms.