Rigid sheet and process for manufacturing rigid sheet

• Main Authors: NAGAYAMA REI, MEGURO MASASI, TAKAOKA NOBUO, HAYASHI KOICHI
• Format: Patent
• Language: English
• Published: 28.10.2015
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; BASIC ELECTRIC ELEMENTS; BRAIDING; CHEMISTRY; COMPOSITIONS BASED THEREON; COTTON-WOOL; DRESSING OR CONDITIONING OF ABRADING SURFACES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS,NON-WOVEN FABRICS; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR; GENERAL PROCESSES OF COMPOUNDING; GRINDING; KNITTING; LACE-MAKING; LAUNDERING; MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARYMATERIAL; METALLURGY; NON-WOVEN FABRICS; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; POLISHING; SEMICONDUCTOR DEVICES; TEXTILES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; TREATMENT OF TEXTILES OR THE LIKE; TRIMMINGS; WADDING; WALL, FLOOR OR LIKE COVERING MATERIALS, e.g. LINOLEUM,OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF AFIBROUS WEB COATED WITH A LAYER OF MACROMOLECULARMATERIAL; WORKING-UP

The invention provides a rigid sheet which comprises both a nonwoven fabric made of ultrafine fibers and a polymeric elastomer applied to the nonwoven fabric, exhibiting a JIS-D hardness of 45 or more, an R% of 0 to 20%, and a total content of ions causing a change in the pH of water of 400[mu]g/cm3 or less. The R% is calculated from six D hardness values according to the formula: R(%)=(maximum D hardness value - minimum D hardness value)/average D hardness value 100. The six D hardness values are determined by: dividing the thicknesswise cross section of the sheet equally into three layers; taking the layers as a first surface layer, an intermediate layer and a second surface layer respectively from one surface side of the sheet; and measuring JIS-D hardness at three arbitrary points in each of the first surface and intermediate layers.