Showa Denko K.k.

Showa Highpolymer Co., Ltd.

Sunallomer Ltd.

Hiroshima University

Hideharu Kimura

Takeshi Nakajima

Yasushi Ichikawa

Akira Ishii

Eiichiro Takiyama

Koji Yamada

Mitsuhiro Imaizumi

Junichiro Washiyama

Masamichi Hikosaka

Kiyoka Okada

Akihiro Otsubo

Kaori Watanabe

Ryosuke Kamei

Yoshihiro Moteki

Takashi Fujimaki

Jun Suzuki

Haruhiko Kondo

Ryutaro Fujihira

Yuuki Tetsuka

There are disclosed a biodegradable resin composition including a starch (a1), a biodegradable resin (a2) other than a polylactic acid-based polymer and a non-crystalline polylactic acid-based polymer (b), a mass ratio of the starch (a1) to the biodegradable resin (a2) other than a polylactic acid-based polymer (a1/a2) being from 20/80 to 50/50, and a mass ratio of a sum of the components other than the polymer (b) to the polymer (b) (sum of components other than polymer (b)/polymer (b)) being from 95/5 to 50/50, and a biodegradable film using the biodegradable resin composition.

Biodegradable resin composition, and biodegradable film

The present invention relates to a method for producing an aliphatic polyester having an increased molecular weight comprising the steps of:

Method for producing an aliphatic polyester having increased molecular weight

A process and apparatus for manufacturing a crystalline resin film or sheet. This manufacturing apparatus includes: an extruder that melts crystalline resin while supplying it; a gear pump that is provided on the downstream side of the extruder; a die which is provided on the downstream side of the gear pump, and which has a slit-shaped aperture; a cooling apparatus which cools film-shaped or sheet-shaped crystalline resin (A) discharged in a melted state from the die to a temperature which is not less than the crystallization temperature but not more than the melting point; and a pair of pinch rolls that press-roll between them the film-shaped or sheet-shaped crystalline resin (B) which has passed through the cooling apparatus (), wherein the pair of guide rolls are positioned such that the thickness of the film-shaped or sheet-shaped crystalline resin (B) which has passed through the cooling apparatus is between 1.3 and 8.0 times the thickness of the film or sheet (C, D) after it has been press-rolled.

Process and apparatus for producing crystalline resin film or sheet

The problem to be solved by the present invention is to provide a method for continuously and effectively producing an aliphatic polyester having an increased molecular weight which prevents evaporation of diisocyanate at the step of mixing the diisocyanate with the aliphatic polyester prepolymer in a molten state at a temperature not lower than the melting point of the prepolymer and enables uniform mixing of the diisocyanate with the aliphatic polyester prepolymer. In order to solve this problem, the present invention provides a method for producing an aliphatic polyester having an increased molecular weight comprising the steps of:

Method for producing aliphatic polyester having increased molecular weight

The present invention addresses the problem of providing a method for continuously and effectively producing an aliphatic polyester having an increased molecular weight by preventing evaporation of a diisocyanate when blending the diisocyanate with an aliphatic polyester prepolymer in a molten state at a temperature not lower than the melting point thereof so that the diisocyanate and the aliphatic polyester prepolymer are uniformly blended. In order to solve the above-mentioned problem, the present invention provides a method for producing an aliphatic polyester having an increased molecular weight comprising the steps of (i) quantitatively injecting a diisocyanate into an aliphatic polyester prepolymer which has a number average molecular weight of 5,000 or higher and has terminal hydroxyl groups and in which at least one acid component is a succinic acid compound, in a melting state at a temperature not lower than the melting point thereof wherein the amount of the diisocyanate is equivalent to between one tenth and two times the amount of hydroxyl groups in the aliphatic polyester prepolymer, (ii) quantitatively and continuously introducing the diisocyanate-containing aliphatic polyester prepolymer obtained at the step (i) into a mixing tank, discharging same from the mixing tank under stirring and supplying it to a coupling reaction tank, and (iii) reacting the aliphatic polyester prepolymer with the diisocyanate in the coupling reaction tank.

A polymer sheet according to at least one embodiment of the present invention is a polymer sheet whose main component is oriented nanocrystals of a polymer, and which satisfies the following conditions (I), (II), and (III): (I) having a crystallinity of not less than 70%; (II) having a tensile strength at break of not less than 100 MPa and a tensile modulus of not less than 3 GPa; and (III) having an average thickness of not less than 0.15 mm. According to at least one embodiment of the present invention, it is possible to provide a polymer sheet excelling in properties such as mechanical strength, heat tolerance, and transparency, particularly a polymer sheet having excellent properties such as mechanical strength, heat tolerance, and transparency in general-purpose plastics such as polypropylene.

Polymer sheet and method for producing same

Aliphatic polyester resin and method for producing same

A method for producing polyester foamed articles comprising: heating and foaming a resin composition comprising a foaming agent, and an aliphatic polyester having a melt viscosity of 1.0.times.10.sup.3 -1.0.times.10.sup.6 poises at a temperature of 190.degree. C. and a shear rate of 100 sec.sup.-1, and having a melting point of 70.degree.-190.degree. C. Extrusion or forming in a mold using preexpanded beads can be applied. The foamed articles such as insulating boxes and cushioning materials have biodegradability and excellent mechanical properties such as tensile strength and cushioning properties.

Polyester foamed articles and method for producing the same

Growing community of inventors

Kawasaki, Japan

Hideharu Kimura