Abstract: A particle size distribution measurement device includes a cell holding body 31 that holds a measurement cell 2 containing a measurement sample and a dispersion medium and a reference cell 6 containing a reference sample and is rotated by a motor 322, and a cell discrimination mechanism 7 that discriminates the cells 2, 6 passing through a predetermined rotation position by using a magnetic force or electrostatic capacitance.

Abstract: A resin with a favorable index of refraction and transparency even without using heavy atoms or inorganic oxide fine particles by means of a polymerizable monomer having a 1,3,5-triazine ring represented by formula 1. (In formula 1: A is a group represented by formula 2, (in formula 2: R1 represents a hydrogen atom or a methyl group, T represents an alkylene having 1-10 carbon atoms, and R2 represents O or NH), and B1 and B2 are each independently groups represented by formula 3, formula 4, or formula 5 (in formulas 3-5: R3, R4, and R5 represent an alkyl group having 1-10 carbon atoms, an aryl group, or an aryloxy group, n1 and n3 are integers from 0-5, and n2 is an integer from 0-7, however when there are at least two of each of R3, R4, and R5, these may be the same or different from each other).

Abstract: A resin with a favorable index of refraction and transparency even without using heavy atoms or inorganic oxide fine particles by means of a polymerizable monomer having a 1,3,5-triazine ring represented by formula 1. (In formula 1: A is a group represented by formula 2, (in formula 2: R1 represents a hydrogen atom or a methyl group, T represents an alkylene having 1-10 carbon atoms, and R2 represents O or NH), and B1 and B2 are each independently groups represented by formula 3, formula 4, or formula 5 (in formulas 3-5: R3, R4, and R5 represent an alkyl group having 1-10 carbon atoms, an aryl group, or an aryloxy group, n1 and n3 are integers from 0-5, and n2 is an integer from 0-7, however when there are at least two of each of R3, R4, and R5, these may be the same or different from each other).

Abstract: An epoxy/acid anhydride composition characterized by containing, as a curing accelerator, a substituted triazine of the formula [I] ##STR1## (wherein X is an amino group, C.sub.1-18 monoalkylamino group, di C.sub.1-18 alkylamino group, morpholino group, piperidino group, methyl group or phenyl group; R.sup.1 and R.sup.2 independently each represent C.sub.1-12 alkyl group, C.sub.1-12 hydroxyalkyl group, C.sub.4-8 cycloalkyl group, C.sub.5-9 cycloalkylmethyl group or C.sub.5-9 methylcycloalkyl group) in an epoxy/acid anhydride composition in which an epoxy compound and an acid anhydride-curing agent are contained, and an epoxy/acid anhydride resin composition prepared by thermosetting the epoxy/acid anhydride composition.

Abstract: In a helicopter toy, a plurality of rotor blades are mounted to a flying body for rotation about a rotational axis and for angular movement about their respective pivotal axes extending perpendicularly to the rotational axis so that the rotor blades have their respective angles of attack which can be altered in pitch. An attack-angle altering unit is provided for altering the angles of attack of the respective rotor blades such that, when a power is transmitted to the rotor blades from a power source to rotate the rotor blades about the rotational axis, the angles of attack of the respective rotor blades are brought to their respective plus pitches to climb the flying body, while, when the transmission of the power from the power source to the rotor blades is released, the angles of attack of the respective rotor blades are brought to their respective minus pitches to cause the flying body to descend.

Abstract: A polymer obtained by the polymerization of a substituted 1,3-butadiene compound of the formula: ##STR1## wherein each of X.sub.1 and X.sub.2 is hydrogen or SiR.sub.1 R.sub.2 R.sub.3, provided that at least one of X.sub.1 and X.sub.2 is SiR.sub.1 R.sub.2 R.sub.3, wherein each of R.sub.1, R.sub.2 and R.sub.3 is halogen, lower alkyl or lower alkoxy, provided that R.sub.1, R.sub.2 and R.sub.3 are not lower alkyl at the same time.