The polyethylene according to the present invention has narrow particle size distribution, and can minimize a change in the crystal structure, and thus, it can be reacted with chlorine to prepare chlorinated polyethylene having excellent chlorination productivity and thermal stability.

The polyethylene according to the present invention has narrow particle size distribution, and can minimize a change in the crystal structure, and thus, it can be reacted with chlorine to prepare chlorinated polyethylene having excellent chlorination productivity and thermal stability.

A process for preparing ethylene polymers including the step of polymerizing ethylene or copolymerizing ethylene and one or more comonomers at a temperature from 100° C. to 350° C. and a pressure of from 110 MPa to 350 MPa in a continuously operated tubular polymerization reactor, thereby yielding a reaction mixture, wherein the tubular polymerization reactor has a reactor cooling jacket for removing the heat of the reaction and a pressure control valve, the reaction mixture leaves the reactor through the pressure control valve, the reaction mixture then passes a post-reactor cooler equipped with a post-reactor cooling jacket, the reactor cooling jacket is provided with a reactor coolant having an inlet temperature and the post-reactor cooling jacket is provided with a post-reactor coolant having an inlet temperature, and the inlet temperature of the post-reactor coolant is independently controlled from the inlet temperature of the reactant coolant.

A process for preparing ethylene polymers including the step of polymerizing ethylene or copolymerizing ethylene and one or more comonomers at a temperature from 100° C. to 350° C. and a pressure of from 110 MPa to 350 MPa in a continuously operated tubular polymerization reactor, thereby yielding a reaction mixture, wherein the tubular polymerization reactor has a reactor cooling jacket for removing the heat of the reaction and a pressure control valve, the reaction mixture leaves the reactor through the pressure control valve, the reaction mixture then passes a post-reactor cooler equipped with a post-reactor cooling jacket, the reactor cooling jacket is provided with a reactor coolant having an inlet temperature and the post-reactor cooling jacket is provided with a post-reactor coolant having an inlet temperature, and the inlet temperature of the post-reactor coolant is independently controlled from the inlet temperature of the reactant coolant.

A process for preparing ethylene polymers including the step of polymerizing ethylene or copolymerizing ethylene and one or more comonomers at a temperature from 100° C. to 350° C. and a pressure of from 110 MPa to 350 MPa in a continuously operated tubular polymerization reactor, thereby yielding a reaction mixture, wherein the tubular polymerization reactor has a reactor cooling jacket for removing the heat of the reaction and a pressure control valve, the reaction mixture leaves the reactor through the pressure control valve, the reaction mixture then passes a post-reactor cooler equipped with a post-reactor cooling jacket, the reactor cooling jacket is provided with a reactor coolant having an inlet temperature and the post-reactor cooling jacket is provided with a post-reactor coolant having an inlet temperature, and the inlet temperature of the post-reactor coolant is independently controlled from the inlet temperature of the reactant coolant.

The present invention provides a composition for hologram recording, a hologram recording medium and a hologram that are capable of realizing excellent diffraction characteristics and an optical device and an optical member using same. The present invention is capable of providing a composition for hologram recording containing at least a radical polymerizable monomer and a matrix resin, in which a cross-sectional observation image at the time of observing a hologram recording film by atomic force microscopy (AFM) has a diffraction grating structure indicating that there is a material density difference that can be observed by the AFM.

Disclosed in the present invention are ABS rubber powder with a low impurity content, a preparation method therefor, and an ABS resin. The ABS rubber powder is treated by using the following steps: washing the ABS rubber powder with a washing solution I, and monitoring the content of soluble organic carbon in the ABS rubber powder until the content of soluble organic carbon in the ABS rubber powder is less than or equal to 9000 ppm, so as to obtain the ABS rubber powder with the low impurity content. In the present invention, by controlling the content of soluble organic carbon or the contents of soluble organic carbon and iron ions in the ABS powder, the ABS resin with a low yellow index of less than or equal to 18 is obtained.

Disclosed in the present invention are ABS rubber powder with a low impurity content, a preparation method therefor, and an ABS resin. The ABS rubber powder is treated by using the following steps: washing the ABS rubber powder with a washing solution I, and monitoring the content of soluble organic carbon in the ABS rubber powder until the content of soluble organic carbon in the ABS rubber powder is less than or equal to 9000 ppm, so as to obtain the ABS rubber powder with the low impurity content. In the present invention, by controlling the content of soluble organic carbon or the contents of soluble organic carbon and iron ions in the ABS powder, the ABS resin with a low yellow index of less than or equal to 18 is obtained.

The present invention relates to a resin composition including a modified petroleum resin having a structure in which a molecular weight regulator is bonded to at least one terminus of both terminuses of an at least partially hydrogenated or non-hydrogenated petroleum resin, and a viscosity of the resin composition measured at a temperature of 25° C. is in a range of 5,000 cps to less than 50,000 cps.

The present invention relates to a resin composition including a modified petroleum resin having a structure in which a molecular weight regulator is bonded to at least one terminus of both terminuses of an at least partially hydrogenated or non-hydrogenated petroleum resin, and a viscosity of the resin composition measured at a temperature of 25° C. is in a range of 5,000 cps to less than 50,000 cps.