US 11,953,650 B2 · Sheet and method for producing sheet

Abstract

The present invention provides a thin sheet with suppressed strain. The sheet according to the present invention has a thickness from 0.1 to 5 mm and is formed of a plastic that contains at least one resin selected from polyamide resins, polycarbonate resins, cellulose acrylate resins, and acrylic resins. A difference between a maximum value and a minimum value of retardation of the sheet is 3000 nm or less. The sheet according to the present invention can be obtained, for example, by subjecting a plastic containing at least one resin selected from polyamide resins, polycarbonate resins, cellulose acylate resins, and acrylic resins to extrusion molding to obtain a plastic in the form of a sheet, and subjecting the resulting plastic in the form of a sheet to vacuum forming, air-pressure forming, or vacuum air-pressure forming.

Claims13

Dependent claims

A sheet having a thickness from 0.1 to 5 mm and comprising a plastic containing at least one resin selected from alicyclic polyamide resins, polycarbonate resins, cellulose acylate resins, and acrylic resins,

wherein the alicyclic polyamide resin contains a repeating unit represented by the below Formula,
where X is a single bond or a divalent hydrocarbon group, L is a divalent hydrocarbon group, R1 and R2 each is an alkyl group, and m and n each is an integer from 0 to 4, and
wherein a difference between a maximum value and a minimum value of retardation of the sheet is 3000 nm or less.

Dependencies are inferred from the claim text.

Facts

Application

16/972,353Filed 31 May 2019

Priority

JP 2018-1081025 Jun 2018

Published

US 2021/0231837 A129 Jul 2021

Granted

9 Apr 2024

Term ends

Not estimatedThe source records don’t support an estimate.

Classification26 codes

G02B 1/041
Made of organic materials, e.g. plastics: lenses
G02C 7/022
Lenses; Lens systems ; Methods of designing lenses: ophthalmic lenses having special refractive features achieved by special materials or material…
B29C 48/0017
Combinations of extrusion moulding with other shaping operations: combined with blow-moulding or thermoforming
B29C 48/022
Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor:…

Sheet and method for producing sheet

Life of this patent

Sheet and method for producing sheet

Life of this patent

Abstract

Claims13