The invention is related to a process for making 2,6-dimethylnaphthalene from p-xylene and 1- or 2-butene or butadiene via 1-(p-tolyl)-2-methylbutane or 1-(p-tolyl)-2-methylbutene. 2,6-dimethylnaphthalene can be used for making polyethylenenaphthalate.

Preferably, the polyester material is polyethylene naphthalate (PEN).

Each first optical layer is formed using a polymer, such as a copolymer of polyethylene naphthalate.

Two laminates each comprising the thin nickel film formed on the polyethylene naphthalate substrate are provided.

A tire with superior properties was produced using reinforcing cords or filaments (27) and (28) which are made from polyethylene napthalate.

The present invention discloses a system and method for distinguishing PEN from other types of materials.

A circuit board which is connected to a conductor on a hard board and whose circuit conductor is sandwiched between polyethylene naphthalate films.

The process involves the use of polyethylene naphthalate film having special qualities for transferring the initial image from an initial surface on which it is provided onto the final surface.

A thin nickel film is formed, for example, to a thickness of not less than 2 nm, onto a polyethylene naphthalate substrate, for example, by a vacuum deposition method.

A polyethylene naphthalate fiber comprising ethylene naphthalate units as main repeating units.

A polyethylene naphthalate fiber comprising ethylene naphthalate units as main repeating units.

The invention is related to a process for making 2,6-dimethylnaphthalene from p-xylene and 1- or 2-butene or butadiene via 1-(p-tolyl)-2-methylbutane or 1-(p-tolyl)-2-methylbutene. 2,6-dimethylnaphthalene can be used for making polyethylenenaphthalate.

Preferably, the polyester material is polyethylene naphthalate (PEN).

Suitable polymers include polyethylene terephthalate or naphthalate homopolymers or copolymers.

The polymer is in particular naphtalate polyethylene (PEN) with a crystalline rate higher than 20 %.