摘要:
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.
摘要:
An aliphatic polyester resin having a .lambda. value representing the magnitude of non-linearity of elongational viscosity of 1.5 to 8.0, said .lambda. value being defined by the following formula (1): .lambda.=.lambda..sub.1 /.lambda..sub.0 ( 1) wherein .lambda..sub.0 denotes the elongational viscosity at the transition point and .lambda..sub.1 denotes the elongational viscosity when strain become twice that of a transition point, said transition point meaning a point between a linear region, i.e., the infinitesimal-deformation region, and a non-linear region, i.e., the large-deformation region. According to the present invention, an aliphatic polyester resin having excellent formability and forming stability as well as good biodegradability is provided.
摘要:
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.
摘要:
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 (40), 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.
摘要:
It is an object to provide a fire-resistant piping material that can be fire-protection measures by itself and is excellent in construction workability. A single-layered fire-resistant piping material according to the present invention is constituted of a fire-resistant resin composition containing heat-expandable graphite in an amount of 1 to 10 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin. A multilayered fire-resistant piping material according to the present invention includes a tubular fire-resistant expandable layer made of a heat-expandable fire-resistant resin composition and a covering layer covering at least one of the outer surface and the inner surface of the fire-resistant expandable layer, and the fire-resistant expandable layer is formed of a fire-resistant resin composition containing heat-expandable graphite in an amount of 1 to 15 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin, and the covering layer is formed of a polyvinyl chloride-based resin composition not containing heat-expandable fire-resistant materials.
摘要:
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: (i) quantitatively injecting a diisocyanate into an aliphatic polyester prepolymer which has a number average molecular weight of 5000 or higher and has terminal hydroxyl groups and in which at least one acid component is a succinic acid compound, in a molten state at a temperature not lower than the melting point thereof, wherein the amount of diisocyanate is equivalent to between one tenth and two times the amount of the hydroxyl groups in the aliphatic polyester prepolymer, (ii) quantitatively and continuously mixing the diisocyanate-containing aliphatic polyester prepolymer obtained at step (i) by a static mixer, discharging same from the static mixer, and then supplying same to a coupling reaction tank, and (iii) reacting the aliphatic polyester prepolymer with the diisocyanate in the coupling reaction tank.
摘要:
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.
摘要:
It is an object to provide a fire-resistant piping material that can be fire-protection measures by itself and is excellent in construction workability. A single-layered fire-resistant piping material according to the present invention is constituted of a fire-resistant resin composition containing heat-expandable graphite in an amount of 1 to 10 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin. A multilayered fire-resistant piping material according to the present invention includes a tubular fire-resistant expandable layer made of a heat-expandable fire-resistant resin composition and a covering layer covering at least one of the outer surface and the inner surface of the fire-resistant expandable layer, and the fire-resistant expandable layer is formed of a fire-resistant resin composition containing heat-expandable graphite in an amount of 1 to 15 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin, and the covering layer is formed of a polyvinyl chloride-based resin composition not containing heat-expandable fire-resistant materials.
摘要:
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: (i) quantitatively injecting a diisocyanate into an aliphatic polyester prepolymer which has a number average molecular weight of 5000 or higher and has terminal hydroxyl groups and in which at least one acid component is a succinic acid compound, in a molten state at a temperature not lower than the melting point thereof, wherein the amount of diisocyanate is equivalent to between one tenth and two times the amount of the hydroxyl groups in the aliphatic polyester prepolymer, (ii) quantitatively and continuously mixing the diisocyanate-containing aliphatic polyester prepolymer obtained at step (i) by a static mixer, discharging same from the static mixer, and then supplying same to a coupling reaction tank, and (iii) reacting the aliphatic polyester prepolymer with the diisocyanate in the coupling reaction tank.
摘要:
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.