Abstract: The problem is to provide a polymerizable compound having suitable polymerization reactivity, a high conversion ratio, low polymerization starting temperature, and high solubility in a liquid crystal composition; a liquid crystal composition containing the compound; and a liquid crystal display device including the composition. A means thereof includes a compound represented by formula (1) and a liquid crystal composition containing the compound. In formula (1), R1, R2 and R3 are independently alkyl or the like; n is 0 or the like; ring A1 is phenyl or the like, and ring A2 and ring A3 are independently 1,4-phenylene or the like; Z1 and Z2 are independently a single bond or the like; Sp1 to Sp4 are a single bond or the like; a is 1 or the like; c, d and e are independently 0 or 1, and a sum of c, d and e is 1 or the like; and P1 to P4 are a polymerizable group, and at least one of P1 to P4 is a polymerizable group represented by formula (P-1).

Abstract: A means is a compound represented by formula (1) , a liquid crystal composition containing the compound, and a liquid crystal display device including the composition. In formula (1), R1 and R2 are independently alkyl having 1 to 15 carbons or the like; ring A1, ring A2 and ring A3 are independently 1,4-cyclohexylene, 1,4-phenylene or the like; and Z1, Z2 and Z3 are independently a single bond or the like.

Abstract: Provided are liquid crystal compounds satisfying at least one of physical properties such as high stability to heat or light, a high clearing point (or high maximum temperature), low minimum temperature of a liquid crystal phase, small viscosity, large optical anisotropy, large negative dielectric anisotropy, a suitable elastic constant and good compatibility with other liquid crystal compounds, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. The compound is represented by formula (1): wherein R1 and R2 are independently hydrogen or alkyl having 1 to 15 carbons; and A1, A2 and A3 are independently 1,4-cyclohexylene or 1,4-phenylene; Z1, Z2 and Z3 are independently a single bond; Y1, Y2, Y3 and Y4 are independently hydrogen, fluorine or the like; and a, b and c are independently 0 or 1, and a sum of a, b and c is 0 to 3.

Abstract: Provided are a liquid crystal compound satisfying at least one of physical properties such as high stability to heat or light, a high clearing point (or high maximum temperature), low minimum temperature of a liquid crystal phase, small viscosity, large optical anisotropy, large negative dielectric anisotropy, a suitable elastic constant and good compatibility with other liquid crystal compounds, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. A compound is represented by formula (1): In formula (1), R1 and R2 are independently hydrogen or alkyl having 1 to 15 carbons; and A1, A2 and A3 are independently 1,4-cyclohexylene or 1,4-phenylene; Z1, Z2 and Z3 are independently a single bond; Y1, Y2, Y3 and Y4 are independently hydrogen, fluorine or the like; and a, b and c are independently 0 or 1, and a sum of a, b and c is 0 to 3.

Abstract: An object is to provide a head and neck protection apparatus for vehicle which is simple in a structure and an operation principle and excellent in reliability and safety and can protect the head and neck part by alleviating not only a rearward impact received by the head part at a rear-end collision but also a forward impact. A head and neck protection apparatus for vehicle according to the present invention is attached to a vehicle seat, provided with a fixed frame having a mounting stay, a swing frame swingably connected with respect to the fixed frame, and a lock stopper for locking the swing frame with respect to the fixed frame, in which the swing frame has a rear-head part contact member with which the rear head part is brought into contact and a front-head part buffer member alleviating an impact of the front head part.

Abstract: An object is to provide a head and neck protection apparatus for vehicle which is simple in a structure and an operation principle and excellent in reliability and safety and can protect the head and neck part by alleviating not only a rearward impact received by the head part at a rear-end collision but also a forward impact. A head and neck protection apparatus for vehicle according to the present invention is attached to a vehicle seat, provided with a fixed frame having a mounting stay, a swing frame swingably connected with respect to the fixed frame, and a lock stopper for locking the swing frame with respect to the fixed frame, in which the swing frame has a rear-head part contact member with which the rear head part is brought into contact and a front-head part buffer member alleviating an impact of the front head part.