The hollow microballoons of the invention are hollow microballoons formed of a resin produced by polymerizing a polymerizing composition that contains a polyrotaxane monomer having at least two polymerizable functional groups in the molecule and a polymerizable monomer other than the polyrotaxane monomer having at least two polymerizable functional groups in the molecule. Using the hollow microballoons of the invention, a CMP polishing pad having excellent polishing characteristics and durability can be provided.

Methods for manufacturing bonded abrasive articles, for example vitrified bonded grinding wheels. A bondable abrasive composition is prepared including abrasive particles, a binder medium and a gamma-pyrone pore inducing material, such as ethyl maltol. A precursor abrasive structure is formed from the composition. The gamma-pyrone pore inducing material is removed from the precursor abrasive structure to provide a porous precursor abrasive structure that is further processed to provide a bonded abrasive article. In some embodiments, the binder medium includes a vitreous bonding material, and the bonded abrasive article is a porous vitrified bonded grinding wheel.

Methods for manufacturing bonded abrasive articles, for example vitrified bonded grinding wheels. A bondable abrasive composition is prepared including abrasive particles, a binder medium and a gamma-pyrone pore inducing material, such as ethyl maltol. A precursor abrasive structure is formed from the composition. The gamma-pyrone pore inducing material is removed from the precursor abrasive structure to provide a porous precursor abrasive structure that is further processed to provide a bonded abrasive article. In some embodiments, the binder medium includes a vitreous bonding material, and the bonded abrasive article is a porous vitrified bonded grinding wheel.

A method of making an abrasive article comprises urging a malleable thermosetting melt-flowable composition through openings extending through a porous abrasive member to form an abrasive article precursor; which is heated to form the abrasive article. Multiple abrasive articles may be stacked prior to heating. Methods can be used to fabricate abrasive articles such as grinding wheels and cut-off wheels.

A method of making an abrasive article comprises urging a malleable thermosetting melt-flowable composition through openings extending through a porous abrasive member to form an abrasive article precursor; which is heated to form the abrasive article. Multiple abrasive articles may be stacked prior to heating. Methods can be used to fabricate abrasive articles such as grinding wheels and cut-off wheels.

The polishing pad is useful in chemical mechanical polishing. The polishing pad includes a polishing portion having a top polishing surface and a polishing material. There is an opening through the polishing pad and a transparent window within the opening. The transparent window is secured to the polishing pad. The window includes a polyurethane composition formed by reacting, in the presence of a hard segment inhibitor for reducing size of hard segment domains, a polymeric polyol, a polyisocyanate and a curing agent. The curing agent includes three or more hydroxyl groups forming hard segments and the polyurethane composition is an amorphous mixture of hard segments in a soft segments matrix and is free of carbon-carbon double bonds.

A subpad for a chemical-mechanical polishing pad, the subpad having porogens with polymeric shells. Methods of fabricating the subpad and polishing pads with a polishing surface layer bonded to the subpad layer are also described.

There are provided a polishing pad and a polishing method using the same that are useful for removing the surface waviness of a curved resin-painted surface at a high polishing removal rate. A polishing pad (10) according to one aspect of the present invention includes a layer having a polishing surface (30). The layer having the polishing surface (30) has a sparse and dense structure in which a proportion of a sparse portion of the polishing surface (30) is 52% or more and 96% or less, and is composed of a sheet material having an A hardness of 70 or more measured according to JIS K 6253.

In an abrasive body used for polishing by a CMP method, provided with a resin structure, a plurality of abrasive grains, and a plurality of longitudinal pores, and made in a form of disc, the longitudinal pore has a length in a thickness direction of the abrasive body longer than a length in a planar direction of the abrasive body, the resin structure includes communicating pores each of which communicating with the longitudinal pore and/or communicating with other communicating pore, the communicating pores include at least one of the abrasive grains in the pores respectively, and the average diameter of the communicating pores is not more than 18 times larger than the average diameter of the abrasive grains.

In an abrasive body used for polishing by a CMP method, provided with a resin structure, a plurality of abrasive grains, and a plurality of longitudinal pores, and made in a form of disc, the longitudinal pore has a length in a thickness direction of the abrasive body longer than a length in a planar direction of the abrasive body, the resin structure includes communicating pores each of which communicating with the longitudinal pore and/or communicating with other communicating pore, the communicating pores include at least one of the abrasive grains in the pores respectively, and the average diameter of the communicating pores is not more than 18 times larger than the average diameter of the abrasive grains.