US 2015/0086768 A1 · POLYLACTIC ACID RESIN SHEET FOR THERMAL MOLDING USE

Abstract

A sheet for thermoforming made of a polylactic acid resin composition containing a polylactic acid-based resin, a plasticizer, and a crystal nucleating agent, wherein the sheet has a thickness of from 0.1 to 1.5 mm, and wherein Re (cal) calculated by the following formula (A): Re (cal)=Re (obs)/d×10−6 (A), wherein Re (obs) is a phase difference (nm) measured at a wavelength selected from wavelengths of from 380 to 780 nm, and d is a thickness (mm) of the sheet, is within the range of 0.001×10−3≦Re(cal)≦1×10−3. The sheet for thermoforming of the present invention has a wide moldable temperature region, so that the sheet can be suitably used in various applications such as food containers, packaging materials for daily sundries and household electric appliances, industrial trays of industrial parts, and the like.

Claims29

Dependent claims

A sheet for thermoforming made of a polylactic acid resin composition comprising a polylactic acid-based resin, a plasticizer, and a crystal nucleating agent, wherein the sheet has a thickness of from 0.1 to 1.5 mm, and wherein Re (cal) calculated by the following formula (A):

Re(cal)=Re(obs)/d×10−6 (A)
wherein Re (obs) is a phase difference (nm) measured at a wavelength selected from wavelengths of from 380 to 780 nm, and d is a thickness (mm) of the sheet,
is within the range of 0.001×10−3≦Re(cal)≦1×10−3.

A method for producing a sheet for thermoforming, comprising the following steps (I) to (III):

step (I):
extruding a polylactic acid resin composition from an extruder at a temperature of from 170° to 240° C. to prepare a sheet molded article;
step (II):
providing the sheet molded article obtained in the step (I) into contact with a cooling roller at a temperature of lower than 40° C., to cool the sheet molded article to a sheet surface temperature of from 0° to 50° C.;
and
step (III):
winding up the sheet molded article from the cooling roller in the step (II) under the condition that a stretching ratio is 12% or less, wherein the sheet for thermoforming has a thickness of from 0.1 to 1.5 mm, made of the polylactic acid resin composition comprising a polylactic acid-based resin, and a plasticizer in an amount of from 1 to 20 parts by weight and a crystal nucleating agent in an amount of from 0.01 to 1 part by weight, based on 100 parts by weight of the polylactic acid-based resin.

4 more elements

Dependencies are inferred from the claim text.

Polylactic acid resin sheet for thermal molding use

Life of this patent

Polylactic acid resin sheet for thermal molding use

Life of this patent

Abstract

Claims29