An article of manufacture. The article of manufacture includes a ring-opened lactide copolymer. The ring-opened lactide copolymer is formed in a process that includes reacting a functionalized lactide monomer with a BPA-derived monomer. The reaction forms a lactide copolymer, which is reacted to form the ring-opened lactide copolymer.

A process of forming a lactide copolymer includes forming a dimethylidene lactide molecule from an L-lactide molecule. The process also includes forming a functionalized lactide monomer from the dimethylidene lactide molecule. The process includes forming a mixture that includes the functionalized lactide monomer and a bisphenol A (BPA) monomer or a BPA-derived monomer. The process further includes polymerizing the mixture to form a lactide copolymer.

The polyester-based resin composition according to the invention is a polyester resin composition, containing: at least a polyester resin (A); and a surfactant (B), in which the polyester resin (A) is a copolymer of a compound having a polyalkylene glycol with from 3 to 50 repeating units as a structure as a constituent component, the surfactant (B) is a nonionic surfactant having a structure of a polyalkylene glycol, and the contact angle of water is 30 or less.

An optical stack includes: a first optical sheet having a first principal face with a concavo-convex structure and a second principal face at an opposite side from the first principal face; and an adhesive layer that is disposed on the first principal face of the first optical sheet. The concavo-convex structure includes a plurality of dents and flat portions between adjacent ones of the plurality of dents. A surface of the adhesive layer and the first principal face of the first optical sheet together define an internal space within each of the plurality of dents. Each of the plurality of dents satisfies 0.10(CA)/C 1.00 and 0.75(CA)/(CB), where A is a maximum height value of the adhesive layer existing in that dent; B is a minimum height value of the adhesive layer existing in that dent; and C is a depth of that dent.

An optical stack includes: a first optical sheet having a first principal face with a concavo-convex structure and a second principal face at an opposite side from the first principal face; and an adhesive layer that is disposed on the first principal face of the first optical sheet. The concavo-convex structure includes a plurality of dents and flat portions between adjacent ones of the plurality of dents. A surface of the adhesive layer and the first principal face of the first optical sheet together define an internal space within each of the plurality of dents. Each of the plurality of dents satisfies 0.10(CA)/C 1.00 and 0.75(CA)/(CB), where A is a maximum height value of the adhesive layer existing in that dent; B is a minimum height value of the adhesive layer existing in that dent; and C is a depth of that dent.

An adhesive layer is formed by cross-linking an adhesive composition containing: a polyester resin that is a copolymer of a polycarboxylic acid and a polyalcohol; a cross-linking agent; and at least one cross-linking catalyst selected from the group consisting of an organic zirconium compound, an organic iron compound, and an organic aluminum compound, the adhesive layer having a gel fraction of 40% or more after being retained at a temperature of 85? C. and a relative humidity of 85% for 300 hours, and having a 180? peel adhesive strength of 100 mN/20 mm or more with respect to a PMMA film.

An adhesive layer is formed by cross-linking an adhesive composition containing: a polyester resin that is a copolymer of a polycarboxylic acid and a polyalcohol; a cross-linking agent; and at least one cross-linking catalyst selected from the group consisting of an organic zirconium compound, an organic iron compound, and an organic aluminum compound, the adhesive layer having a gel fraction of 40% or more after being retained at a temperature of 85? C. and a relative humidity of 85% for 300 hours, and having a 180? peel adhesive strength of 100 mN/20 mm or more with respect to a PMMA film.

The polyester-based resin composition according to the present invention is, at least, a polyester-based resin composition including: a polyester resin (A); a surfactant (B); and a terpene-based resin (C), in which the polyester resin (A) is obtained by copolymerizing, as a constituent component, a compound that has, as a frame, a polyalkylene glycol having a number of repeating units of from 3 to 50, in which the surfactant (B) is a non-ionic surfactant having a polyalkylene glycol frame, in which a mixing ratio (A)/(C) of the polyester resin (A) to the terpene-based resin (C) is from 80/20 to 99/1 by mass ratio, and in which the polyester-based resin composition has a water contact angle of 30 or less.

The polyester-based resin composition according to the present invention is, at least, a polyester-based resin composition including: a polyester resin (A); a surfactant (B); and a terpene-based resin (C), in which the polyester resin (A) is obtained by copolymerizing, as a constituent component, a compound that has, as a frame, a polyalkylene glycol having a number of repeating units of from 3 to 50, in which the surfactant (B) is a non-ionic surfactant having a polyalkylene glycol frame, in which a mixing ratio (A)/(C) of the polyester resin (A) to the terpene-based resin (C) is from 80/20 to 99/1 by mass ratio, and in which the polyester-based resin composition has a water contact angle of 30 or less.

Provided is a polyester composite film, comprising a first thermoplastic polyether ester elastomer (TPEE) film and a second TPEE film. The melting point of a second TPEE resin of the second TPEE film is higher than that of a first TPEE resin of the first TPEE film, and the absolute difference in enthalpy of fusion between the first and second TPEE films is 5 J/g to 15 J/g. By adopting the first and second TPEE films having specific absolute difference of the enthalpy of fusion and controlling the melting points of the first and second TPEE resins, the polyester composite film can be well attached onto the fabric by hot pressing to obtain sufficient peel strength, and thereby the attached fabric can have excellent waterproof performance. Besides, a hot melt adhesive laminate comprising the polyester composite film also exhibits the above beneficial effects when attached to the fabric.