초록 ▼

A rental system contains a plurality of rental digital cameras, and comprises a rental-item providing machine which provides users with digital cameras, respectively, and a management center which manages the digital cameras. The rental-item providing machine makes a credit inquiry about the users.

A rental system contains a plurality of rental digital cameras, and comprises a rental-item providing machine which provides users with digital cameras, respectively, and a management center which manages the digital cameras. The rental-item providing machine makes a credit inquiry about the users. The rental-item providing machine provides the users with the respective digital cameras, in accordance with a result of the credit inquiry. The rental-item providing machine sends identification information for identifying each of the contained digital cameras, to the management center. The management center manages the digital cameras, using the identification information sent from the rental-item providing machine.

대표청구항 ▼

A rental system contains a plurality of rental digital cameras, and comprises a rental-item providing machine which provides users with digital cameras, respectively, and a management center which manages the digital cameras. The rental-item providing machine makes a credit inquiry about the users.

A rental system contains a plurality of rental digital cameras, and comprises a rental-item providing machine which provides users with digital cameras, respectively, and a management center which manages the digital cameras. The rental-item providing machine makes a credit inquiry about the users. The rental-item providing machine provides the users with the respective digital cameras, in accordance with a result of the credit inquiry. The rental-item providing machine sends identification information for identifying each of the contained digital cameras, to the management center. The management center manages the digital cameras, using the identification information sent from the rental-item providing machine. containing active component comprising the reaction product of: a) at least one titanium compound; b) at least one magnesium compound, wherein the magnesium compound is represented by the following general formula: MgX2 wherein X is Cl, Br, I or combinations thereof c) at least one halide promoter; d) at least one electron donor; and (ii) a porous inert carrier material, wherein said porous inert carrier material is spherical or spheroidal silica gel having an average particle size of 10 to 100 microns and a specific surface area of 300 to 1000 m2/g, said active component being supported on the carrier material. 2. The supported catalyst component according to claim 1 wherein said titanium compound is represented by any of the following general formulae: Ti(OR)4-nXnor TiX3 wherein R is a C1-C14aliphatic hydrocarbyl, X is F, Cl, Br or combinations thereof and n is an integer of 1 to 4. 3. The supported catalyst component according to claim 2 wherein said titanium compound is selected from titanium tetrachloride, titanium trichloride, titanium tetrabromide, titanium tetraiodide, titanium tetrabutoxide, titanium tetraethoxide, triethoxy titanium chloride, diethoxy titanium dichloride, ethoxy titanium and mixtures thereof. 4. The supported catalyst component according to claim 1 wherein said magnesium compound is selected from the group consisting of magnesium, dichloride, magnesium dibromide, magnesium diiodide and mixtures thereof. 5. The supported catalyst component according to claim 1 wherein said halide promoter is a class of compounds represented by general formula F--R1[R2bX(3-b) ], wherein F represents a functional group selected from the group consisting of aldhehyde, acyl, hydroxyl, amino, and ester; R1represents a divalent C1-C6aliphatic or aromatic group which is attached to the functional group F; R2represents hydrogen, unsubstituted or halogen-substituted C1-C6alkyl, C3-C6cycloalkyl or C6-C10aromatic groups, b is 0, 1 or 2 and X is F, Cl or Br. 6. The supported catalyst component according to claim 5 wherein said halide promoter is selected from the group consisting of 2,2,2-trichloroethanol, 2,2-dichloroethanol, 2-chloroethanol, 1,1-dimethyl-2,2,2-trichloroethanol, 4-chlorobutanol, para-chlorophenol, iso-chlorophenol, ortho-chlorophenol and 2-chlorocyclohexanol. 7. The supported catalyst component according to claim 5 wherein said halide promoter is selected from the group consisting of trichloroacetyl chloride, dichloroacetyl chloride, chloroacetyl chloride, o-chlorobenzoyl chloride and 2-chlorocyclohexyl carbonyl chloride. 8. The supported catalyst component according to claim 1 wherein said electron donor is selected from the group consisting of alkyl esters of C1-C4saturated aliphatic carboxylic acids, alkyl esters of C7-C8aromatic carboxylic acids, C2-C6aliphatic esters, C3-C4cyclic ethers, C3-C6saturated aliphatic ketones and mixtures thereof. 9. The supported catalyst component according to claim 8 wherein said electron donor is selected from the group consisting of methyl formate, ethyl acetate, butyl acetate, diethyl ether, dihexyl ether, tetrahydrofuran, acetone, methyl isobutyl ketone and mixtures thereof. 10. The supported catalyst component according to claim 1 wherein the magnesium compound, the electron donor and the halide promoter are used in amounts of 0.5 to 50 moles, 0.5 to 50 moles and 0.5 to 50 moles, per mole of the titanium compound, respectively. 11. The supported catalyst component according to claim 1 wherein said silica gel has a pore volume of 1.0 to 6.0 ml/g and an average pore diameter of 5 to 45 nanometers. 12. The supported catalyst co mponent according to claim 1 wherein said silica gel has a specific surface area of 400 to 800 m2/g. 13. The supported catalyst component according to claim 12 wherein said silica gel has an average particle size of 20 to 80 microns, a pore volume of 2.0 to 5.0 ml/g and an average pore diameter of 10 to 35 nanometers. 14. The supported catalyst component according to claim 1 wherein said silica gel has a specific surface area of 600 to 800 m2/g. 15. A catalyst comprising the reaction product of: A) the supported catalyst component according to claim 1, and B) an alkyl aluminum compound. 16. The catalyst according to claim 15 wherein the alkyl aluminum compound is selected from the group consisting of AlEt3,Al(iso-Bu)3,Al(n-C6H13)3,Al(n-C8H17)3,AlEt2Cl and mixtures thereof. 17. A method for ethylene (co)polymerization comprising: (i) providing the catalyst component of claim 15, and (ii) copolymerizing ethylene and another olefin in a gas phase or slurry process in the presence of said catalyst. 18. A method for ethylene polymerization comprising: (i) providing the catalyst of claim 15; and (ii) polymerizing ethylene by a gas phase fluidized bed process operated in a condensed state in the presence of said catalyst.