Toyo Tire Rubber Co., Ltd.

Other

Takashi Masui

Koichi A Ono

Kazuyuki Ogawa

Hiroshi Seyanagi

Atsushi Kazuno

Masahiko Nakamori

Takatoshi Yamada

Kaoru Inoue

Tetsuo Shimomura

Tsuyoshi Kimura

Shigeru Komai

The invention provides a polishing pad by which optical materials such as lenses, reflecting mirrors etc., or materials requiring a high degree of surface planarity, as in the polishing of silicone wafers, glass substrates or aluminum substrates for hard disks, or general metal polishing, can be flattened with stability and high polishing efficiency. The invention also provides a polishing pad for semiconductor wafers, which is superior in planarizing characteristic, is free from scratches and can be produced at low cost. There is provided a polishing pad which is free from dechucking error so that neither damage to wafers nor decrease in operating efficiency occurs. There is provided a polishing pad which is satisfactory in planarity, within wafer uniformity, and polishing rate and produces less change in polishing rate. There is provided a polishing pad which can make planarity improvement and scratch decrease compatible.

Polishing pad and method of producing the same

Grinding pad and method of producing the same

A polyurethane composition containing solid beads dispersed therein, is formed of a microcellular polyurethane foam, and the composition has a storage modulus of elasticity at 40&#xb0; C. of 270 MPa or more as measured by means of a dynamic elasticity measuring device. Another polyurethane composition of this invention contains solid beads dispersed therein, that are capable of swelling with or are soluble in an aqueous medium. The former composition has excellent flattening capability, and the latter composition can provide a polished surface which combines good flatness and good uniformity and can also reduce scratches on the surface.

Polyurethane composition and polishing pad

A process for producing a finely cellular polyurethane foam by mixing a first ingredient comprising an isocyanate compound and a second ingredient comprising a compound containing an active hydrogen group, characterized by comprising adding a nonionic silicone surfactant containing no hydroxyl group to at least one of the first ingredient and the second ingredient in an amount of 0.1 to 5 wt %, excluding 5 wt %, based on the total amount of the first ingredient and the second ingredient, subsequently agitating the surfactant containing ingredient together with an unreactive gas, which has no reactivity to isocyanate group or active hydrogen group, to disperse the unreactive gas as fine bubbles to prepare a bubble dispersion and then mixing the bubble dispersion with the remaining ingredient to cure the resultant mixture and forming finely cellular structure into the resultant polyurethane foam by the fine bubbles of the bubble dispersion.

Process for producing polyurethane foam

Growing community of inventors

Ohtsu, Japan

Takashi Masui