Abstract: A control method of a plasma processing apparatus including a first electrode that places a workpiece thereon includes supplying a bias power to the first electrode, and supplying a source power having a frequency higher than that of the bias power into a plasma processing space. The source power has a first state and a second state. The control method further includes a first control process of alternately applying the first state and the second state of the source power in synchronization with a signal synchronized with a cycle of a radio frequency of the bias power, or a phase within one cycle of a reference electrical state that represents any one of a voltage, current, and electromagnetic field measured in a power feeding system of the bias power.

Abstract: A hitting sound reducing material made of a (meth)acrylic acid ester polymer (B) comprising: a polymer (b1) comprising a structural unit derived from an acrylic ester compound and a structural unit derived from a methacrylic ester compound, and having a glass transition temperature of ?15° C. to +5° C.; and a polymer (b2) comprising at least one selected from the group consisting of a structural unit derived from a methacrylic acid ester compound, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from a vinyl cyanide compound, wherein the polymer (b1) has a temperature (peak temperature) indicating a peak value of a main dispersion of tan ? of ?5° C. to +20° C., and a peak intensity, which is a peak value of the intensity, of 2.055 or more.

Abstract: A hitting sound reducing material made of a (meth)acrylic acid ester polymer (B) comprising: a polymer (b1) comprising a structural unit derived from an acrylic ester compound and a structural unit derived from a methacrylic ester compound, and having a glass transition temperature of ?15° C. to +5° C.; and a polymer (b2) comprising at least one selected from the group consisting of a structural unit derived from a methacrylic acid ester compound, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from a vinyl cyanide compound, wherein the polymer (b1) has a temperature (peak temperature) indicating a peak value of a main dispersion of tan ? of ?5° C. to +20° C., and a peak intensity, which is a peak value of the intensity, of 2.055 or more.

Abstract: An emulsion composition according to the present invention includes: a polymerizable compound comprising two or more (meth)acryloyl groups; a surfactant; and a dispersion medium including water as a principal component, in which an oil droplet diameter D90 corresponding to a diameter at cumulative 90% by volume in the oil droplet size distribution of oil droplets comprising the polymerizable compound and the surfactant, measured according to a laser diffraction and scattering measurement process is less than 1.8 ?m. A maximum oil droplet diameter Dmax of the oil droplets, measured according to the laser diffraction and scattering measurement process is preferably less than 4.0 ?m. A content of the polymerizable compound in the composition with respect to 100 parts by mass of a total of components other than the dispersion medium is preferably no less than 40 parts by mass. The oil droplets may further comprise an inorganic particle.

Abstract: An emulsion composition according to the present invention includes: a polymerizable compound comprising two or more (meth)acryloyl groups; a surfactant; and a dispersion medium including water as a principal component, in which an oil droplet diameter D90 corresponding to a diameter at cumulative 90% by volume in the oil droplet size distribution of oil droplets comprising the polymerizable compound and the surfactant, measured according to a laser diffraction and scattering measurement process is less than 1.8 ?m. A maximum oil droplet diameter Dmax of the oil droplets, measured according to the laser diffraction and scattering measurement process is preferably less than 4.0 ?m. A content of the polymerizable compound in the composition with respect to 100 parts by mass of a total of components other than the dispersion medium is preferably no less than 40 parts by mass. The oil droplets may further comprise an inorganic particle.