Ultraviolet ray curable ink composition for use in ink jet method and recorded object

Abstract

An ultraviolet ray curable ink composition is provided. The ultraviolet ray curable ink composition contains a polymerizable compound; and an aluminum pigment subjected to a surface treatment with a phosphate compound. The aluminum pigment subjected to the surface treatment with the phosphate compound is subjected to an X-ray photoelectron spectrometer to obtain an X-ray photoelectron spectrum having a wave form. Thereafter, when a waveform separation was performed by using a Voigt function in such an X-ray photoelectron spectrum, the X-ray photoelectron spectrum has peaks in the rage of 190 eV or more but 192 eV or less. A printed object is also provided. The printed object is produced by applying the ultraviolet ray curable ink composition onto a recording medium, and then irradiating the ultraviolet ray curable ink composition with an ultraviolet ray.

What is claimed is: 
     
         1 . An ultraviolet ray curable ink composition adapted to be ejected by using an ink jet method, comprising:
 a polymerizable compound; and   an aluminum pigment subjected to a surface treatment with a phosphate compound, the aluminum pigment having particles,   wherein the aluminum pigment subjected to the surface treatment with the phosphate compound is subjected to an X-ray photoelectron spectrometer to obtain an X-ray photoelectron spectrum having a wave form, and then when a waveform separation was performed by using a Voigt function in such an X-ray photoelectron spectrum, the X-ray photoelectron spectrum has peaks in the range of 190 eV or more but 192 eV or less, and   wherein in the case where an area of each of the particles observed from a planar view direction where a project area thereof becomes maximum is defined as S 1  and an area of the particle observed from a direction where the area of the particle observed from directions orthogonal to the planar view direction becomes maximum is defined as S 0 , a ratio of S 1  to S 0  (S 1 /S 0 ) is 2 or more.   
     
     
         2 . The ultraviolet ray curable ink composition as claimed in  claim 1 , wherein the phosphate compound has a chemical structure represented by the following formula (1):
   POR n (OH) 3-n   (1)
   where in the above formula (1), “R” is CH 3 (CH 2 ) m —, CH 3 (CH 2 ) m (CH 2 O) l —, CH 3 (CH 2 ) m (CH 2 CH 2 O) l — or CH 3 (CH 2 ) m O—, “n” is an integral number in the range of 1 or more but 3 or less, “m” is an integral number in the range of 2 or more but 18 or less, and “l” is an integral number in the range of 1 or more but 18 or less.   
     
     
         3 . The ultraviolet ray curable ink composition as claimed in  claim 1 , wherein the phosphate compound has a chemical structure represented by the following formula (2):
   POR n (OH) 3-n   (2)
   where in the above formula (2), “R” is CF 3 (CF 2 ) m —, CF 3  (CF 2 ) m (CH 2 ) l —, CF 3  (CF 2 ) m (CH 2 O) l —, CF 3  (CF 2 ) m (CH 2 CH 2 O) l —, CF 3 (CF 2 ) m O— or CF 3 (CF 2 ) m (CH 2 ) l O—, “n” is an integral number in the range of 1 or more but 3 or less, “m” is an integral number in the range of 2 or more but 18 or less, and “l” is an integral number in the range of 1 or more but 18 or less.   
     
     
         4 . The ultraviolet ray curable ink composition as claimed in  claim 3 , wherein the phosphate compound has a perfluoro alkyl structure. 
     
     
         5 . The ultraviolet ray curable ink composition as claimed in  claim 1 , wherein each of the particles of the aluminum pigment is formed into a scaly shape. 
     
     
         6 . The ultraviolet ray curable ink composition as claimed in  claim 5 , wherein an average thickness of the particles of the aluminum pigment is in the range of 10 nm or more but 100 nm or less. 
     
     
         7 . The ultraviolet ray curable ink composition as claimed in  claim 1 , wherein an average particle size in 50% of the particles of the aluminum pigment is in the range of 0.5 μm or more but 3.0 μm or less, and a maximum particle size of the particles of the aluminum pigment is 5.0 μm or less. 
     
     
         8 . The ultraviolet ray curable ink composition as claimed in  claim 1  further comprising a dispersant having a basic property and a polymer structure. 
     
     
         9 . The ultraviolet ray curable ink composition as claimed in  claim 1 , wherein the polymerizable compound contains phenoxy ethyl acrylate. 
     
     
         10 . The ultraviolet ray curable ink composition as claimed in  claim 9 , wherein the polymerizable compound contains at least one selected from the group consisting of ethyl 2-(2-hydroxy ethoxy) acrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, 2-hydroxy 3-phenoxypropyl acrylate and 4-hydroxy butyl acrylate in addition to the phenoxy ethyl acrylate. 
     
     
         11 . The ultraviolet ray curable ink composition as claimed in  claim 1 , wherein the polymerizable compound contains at least one selected from the group consisting of dimethylol tricyclodecane diacrylate, dimethylol dicyclopentane diacrylate, dicyclopentenyl acrylate, dicyclopentanyl acrylate, isobornyl acrylate, acryloyl morpholine, tetrahydrofurfuryl acrylate, ethylcarbitol acrylate and methoxy triethylene glycol acrylate. 
     
     
         12 . The ultraviolet ray curable ink composition as claimed in  claim 1  further comprising a substance A having a partial structure represented by the following formula (5), 
       
         
           
           
               
               
           
         
         where in the formula (5), R 1  is a hydrogen atom, a hydrocarbon group or an alkoxy silyl group, and each of R 2 , R 3 , R 4  and R 5  is independently a hydrogen atom or a hydrocarbon group. 
       
     
     
         13 . The ultraviolet ray curable ink composition as claimed in  claim 12 , wherein an amount of the substance A is defined as X A  [mass %] and an amount of the aluminum pigment is defined as X M  [mass %], X A  and X M  satisfy a relationship of 0.01≦X A /X M ≦0.8. 
     
     
         14 . A printed object produced by applying the ultraviolet ray curable ink composition defined by  claim 1  onto a recording medium, and then irradiating the ultraviolet ray curable ink composition with an ultraviolet ray.