Recording unit and image recording apparatus

Claim 2

A recording unit comprising an ink housing part for housing an ink containing a coloring material and an aqueous medium, and an ink jet head part for discharging an ink droplet of the ink, wherein at least one color of the ink is a polyvalent metal salt containing ink; the ink jet head part has a configuration comprised of a substrate having on a base body, a heat-generating resistor member forming a heat-generating part, an electrode wire electrically connected to the heat-generating resistor member, and a cavitation resistant film provided on the heat-generating resistor member and the electrode wire via an insulating protection layer, and a liquid flow path communicating with a discharge port for discharging an ink droplet provided corresponding to the heat-generating part; and the cavitation resistant film comprises a first layer comprised of an amorphous alloy containing Ta and a second layer comprised of an amorphous body of an amorphous alloy which is richer in Ta than the amorphous alloy containing Ta or a passive matter of the amorphous body provided on the first layer.

Claim 3

The recording unit according to claim 1 , wherein the ink housing part further comprises a black ink housing part for housing a black ink and an ink jet head part for discharging the black ink, and wherein the black ink contains a salt, an aqueous medium, and a pigment dispersed in the aqueous medium by an action of an ionic group; the polyvalent metal salt containing ink is a color ink; and the polyvalent metal salt functions as a component to lower the dispersion stability of the pigment of the black ink.

Claim 4

The recording unit according to claim 2 , wherein the black ink contains an anionic group as the ionic group.

Claim 5

The recording unit according to claim 1 , wherein the polyvalent metal salt contains at least one polyvalent metal cation selected from the group consisting of Mg 2+ , Ca 2+ , Cu 2+ , Co 2+ , Ni 2+ , Fe 2+ , La 3+ , Nd 3+ , Y 3+ , and Al 3+ .

Claim 6

The recording unit according to claim 1 , wherein the content of the polyvalent metal salt is 0.1 to 15% by weight on the basis of the total weight of the ink.

Claim 7

The recording unit according to claim 1 , wherein the Ka value of the black ink according to the Bristow method is less than 1.5 mL·m −2 ·msec −½ and the Ka value of the color ink according to the Bristow method is not less than 5 mL·m −2 ·msec −½ .

Claim 8

The recording unit according to claim 6 , wherein the Ka value of the black ink according to the Bristow method is not less than 0.2 mL·m −2 ·msec −½ but less than 1.5 mL·m −2 ·msec −½ .

Claim 9

The recording unit according to claim 2 , wherein the salt contained in the black ink is at least one selected from the group consisting of (M1) 2 SO 4 , CH 3 COO(M1), Ph—COO(M1), (M1)NO 3 , (M1)Cl, (M1)Br, (M1)I, (M1) 2 SO 3 , and (M1) 2 CO 3 wherein M1 is an alkali metal, ammonium or organic ammonium.

Claim 10

The recording unit according to claim 1 , wherein the coloring material of the black ink is carbon black to a surface of which at least one hydrophilic group as the ionic group is bound directly or through a group.

Claim 11

The recording unit according to claim 1 , wherein the black ink contains carbon black as the coloring material and further contains a dispersing agent comprising the ionic group.

Claim 12

The recording unit according to claim 8 , wherein the content of carbon black in the black ink is such that when forming an image only with the black ink, a predetermined optical density that can not be achieved without incorporation of the salt can be achieved.

Claim 13

The recording unit according to claims 2 , wherein the coloring material of the color ink is an acid dye or direct dye.

Claim 14

The recording unit according to claim 12 , wherein the light fading property of the color of the color ink in a light resistance test under such conditions as to cause a fading corresponding to indoor light fading for more than three years is such that the difference in ΔE in the CIELAB color space indication system is 10 or less.

Claim 15

The recording unit according to claim 12 , wherein the light fading property of the color of each ink is 70% or more in terms of the reflection density remaining percentage after the indoor light fading for more than three years in the light resistance test.

Claim 16

The recording unit according to claim 12 , wherein when a light resistance test of the inks is conducted under such conditions as to cause fading corresponding to simulated indoor window-passing sunlight fading for more than three years, the light fading property of the color of each ink in the CIELAB color space indication system is 80% or more in terms of the reflection density remaining percentage.

Claim 17

The recording unit according to claim 12 , wherein the irradiation dose supposed for the indoor window-passing sunlight in the light resistance test is 6,000 klux·hr or more.

Claim 18

The recording unit according to claim 12 , wherein the light resistance test is conducted under the conditions supposing the indoor window-passing sunlight according to the ISO standard.

Claim 19

The recording unit according to claim 12 , wherein the light resistance test is conducted for an image formed using a special medium as a recording medium for the inks.

Claim 20

The recording unit according to claim 2 , wherein the color ink includes at least cyan, magenta, and yellow inks.

Claim 21

An ink set as set forth in claim 1 , comprising a first color ink and a second color ink of the same color tone as the first color ink, wherein the absorbance at a maximum absorption wavelength in the visible light region of the first color ink is greater than the absorbance at a maximum absorption wavelength in the visible light region of the second color ink.

Claim 22

The recording unit according to claim 12 , wherein a magenta ink is used which contains at least one coloring material represented by the general formula (I): (wherein R 1 represents an alkoxy group, a substituted alkoxy group, an aryl group, or a substituted aryl group; R 2 and R 4 independently represent a hydrogen atom, an alkyl group, or a substituted alkyl group; R 3 represents a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxy group, a substituted alkoxy group, an aryloxy group, a substituted aryloxy group, or an halogen atom; X 1 represents a carboxyl group or a salt thereof or a sulfonic group or a substituted group of a salt thereof; and n represents an integer of 1 to 2).

Claim 23

The recording unit according to claim 12 , wherein a magenta ink is used which contains at least one of a coloring material of the general formula (I), a coloring material of the general formula (II), the general formula (III), and a coloring material of a xanthene structure: (wherein R 1 represents an alkoxy group, a substituted alkoxy group, an aryl group, or a substituted aryl group; R 2 and R 4 independently represent a hydrogen atom, an alkyl group, or a substituted alkyl group; R 3 represents a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxy group, a substituted alkoxy group, an aryloxy group, a substituted aryloxy group, or an halogen atom; X 1 represents a carboxyl group or a salt thereof or a sulfonic group or a substituted group of a salt thereof; and n represents an integer of 1 to 2); (wherein Ar 1 represents a group having an aryl group having at least one substituent selected from a carboxyl group or a salt thereof and a sulfonic group or a salt thereof, or a substituted or unsubstituted alkyl group; Ar 2 represents an acetyl group, a benzoyl group, a 1,3,5-triazine derivative, SO 2 —C 6 H 5 group, or SO 2 —C 6 H 4 —CH 3 group; and M 2 and M 3 are counterions and independently represent an alkali metal, ammonium or organic ammonium); and (wherein Ar 3 and Ar 4 independently represent an aryl group or a substituted aryl group and at least one of Ar 3 and Ar 4 has a substituent of a carboxyl group or a salt thereof, or a sulfonic group or a salt thereof; M is a counterion and represents an alkali metal, ammonium or organic ammonium; R 5 represents 1,3,5-triazine or a 1,3,5-triazine derivative; R 6 and R 7 independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group, or a substituted aralkyl group, or an atomic group which together with the N forms a perhydroxyazine ring; and L represents a divalent organic linking group).

Claim 24

The recording unit according to claim 12 , wherein as the color ink, a cyan ink is used which contains at least one coloring material having a copper phthalocyanine structure.

Claim 25

The recording unit according to claim 12 , wherein as the color ink, a cyan ink is used which contains Direct Blue 199 as the coloring material.

Claim 26

The recording unit according to claim 12 , wherein as the coloring material of the yellow ink, Direct Yellow 132 is used.

Claim 27

The recording unit according to claim 1 , wherein the coloring material of the color ink is a pigment.

Claim 28

The recording unit according to claim 1 , wherein the liquid flow path of the ink jet head part has a bubble generating region for generating a bubble in the ink in the liquid flow path and a movable member which is provided facing the bubble generating region and moves in accordance with the growth of the bubble.

Claim 29

The recording unit according to claim 27 , wherein the liquid flow path further has a regulating part for regulating the movement of the movable member in accordance with the growth of the bubble such that the movable member moves to substantially contact the regulating part, thereby substantially separating the liquid flow path with regard to a direction of flow of the ink to the discharge port.

Claim 30

The recording unit according to claim 27 , wherein a free end of the movable member is located substantially at a central part of the bubble generating region.

Claim 31

An image recording apparatus comprising the recording unit as set forth in claims 1 to 29 .

Claim 32

A recording unit comprising an ink housing part for housing an ink containing a coloring material and an aqueous medium, and an ink jet head part for discharging an ink droplet of the ink, wherein at least one color of the ink is a polyvalent metal salt containing ink further containing a polyvalent metal salt; the ink jet head part for discharging at least the polyvalent metal salt containing ink has a configuration comprised of a substrate having on a base body, a heat-generating resistor member forming a heat-generating part, an electrode wire electrically connected to the heat-generating resistor member, and a cavitation resistant film provided on the heat-generating resistor member and the electrode wire via an insulating protection layer, and a liquid flow path communicating with a discharge port for discharging an ink droplet provided corresponding to the heat-generating part, and wherein the cavitation resistant film is comprised of at least two layers of an upper layer for contacting the ink comprising Ta or TaAl and a lower layer comprising an amorphous alloy containing Ta.

Claim 33

A recording unit comprising an ink housing part for housing an ink containing a coloring material and an aqueous medium, and an ink jet head part for discharging an ink droplet of the ink, wherein at least one color of the ink is a polyvalent metal salt containing ink further containing a polyvalent metal salt; the ink jet head part for discharging at least the polyvalent metal salt containing ink has a configuration comprised of a substrate having on a base body, a heat-generating resistor member forming a heat-generating part, an electrode wire electrically connected to the heat-generating resistor member, and a cavitation resistant film provided on the heat-generating resistor member and the electrode wire via an insulating protection layer, and a liquid flow path communicating with a discharge port for discharging an ink droplet provided corresponding to the heat-generating part, and wherein the cavitation resistant film is comprised of at least two layers of an upper layer for contacting the ink comprising Ta or TaAl and a lower layer comprising an amorphous alloy containing Ta.

Claim 34

The recording unit according to claim 31 , wherein the ink housing part further comprises a black ink housing part for housing a black ink and an ink jet head part for discharging the black ink, and wherein the black ink contains a salt, an aqueous medium, and a pigment dispersed in the aqueous medium by an action of an ionic group; the polyvalent metal salt containing ink is a color ink; and the polyvalent metal salt functions as a component to lower the dispersion stability of the pigment of the black ink.

Claim 35

The recording unit according to claim 32 , wherein the black ink contains an anionic group as the ionic group.

Claim 36

The recording unit according to claim 31 , wherein the polyvalent metal salt contains at least one polyvalent metal cation selected from the group consisting of Mg 2+ , Ca 2+ , Cu 2+ , Co 2+ , Ni 2+ , Fe 2+ , La 3+ , Nd 3+ , Y 3+ , and Al 3+ .

Claim 37

The recording unit according to claim 31 , wherein the content of the polyvalent metal salt is 0.1 to 15% by weight on the basis of the total weight of the ink.

Claim 38

The recording unit according to claim 31 , wherein the Ka value of the black ink according to the Bristow method is less than 1.5 mL·m −2 ·msec −½ and the Ka value of the color ink according to the Bristow method is not less than 5 mL·m −2 ·msec −½ .

Claim 39

The recording unit according to claim 31 , wherein the Ka value of the black ink according to the Bristow method is not less than 0.2 mL·m −2 ·msec −½ but less than 1.5 mL·m −2 ·msec −½ .

Claim 40

The recording unit according to claim 32 , wherein the salt contained in the black ink is at least one selected from the group consisting of (M1) 2 SO 4 , CH 3 COO(M1), Ph—COO(M1), (M1)NO 3 , (M1)Cl, (M1)Br, (M1)I (M1) 2 SO 3 , and (M1) 2 CO 3 wherein M1 is an alkali metal, ammonium or organic ammonium.

Claim 41

The recording unit according to claim 31 , wherein the coloring material of the black ink is carbon black to a surface of which at least one hydrophilic group as the ionic group is bound directly or through a group.

Claim 42

The recording unit according to claim 31 , wherein the black ink contains carbon black as the coloring material and further contains a dispersing agent comprising the ionic group.

Claim 43

The recording unit according to claim 38 , wherein the content of carbon black in the black ink is such that when forming an image only with the black ink, a predetermined optical density that can not be achieved without incorporation of the salt can be achieved.

Claim 44

The recording unit according to claim 32 , wherein the coloring material of the color ink is an acid dye or direct dye.

Claim 45

The recording unit according to claim 42 , wherein the light fading property of the color of the color ink in a light resistance test under such conditions as to cause a fading corresponding to indoor light fading for more than three years is such that the difference in ΔE in the CIELAB color space indication system is 10 or less.

Claim 46

The recording unit according to claim 42 , wherein the light fading property of the color of each ink is 70% or more in terms of the reflection density remaining percentage after the indoor light fading for more than three years in the light resistance test.

Claim 47

The recording unit according to claim 42 , wherein when a light resistance test of the inks is conducted under such conditions as to cause fading corresponding to simulated indoor window-passing sunlight fading for more than three years, the light fading property of the color of each ink in the CIELAB color space indication system is 80% or more in terms of the reflection density remaining percentage.

Claim 48

The recording unit according to claim 42 , wherein the irradiation dose supposed for the indoor window-passing sunlight in the light resistance test is 6,000 klux·hr or more.

Claim 49

The recording unit according to claim 42 , wherein the light resistance test is conducted under the conditions supposing the indoor window-passing sunlight according to the ISO standard.

Claim 50

The recording unit according to claim 42 , wherein the light resistance test is conducted for an image formed using a special medium as a recording medium for the inks.

Claim 51

The recording unit according to claim 32 , wherein the color ink includes at least cyan, magenta, and yellow inks.

Claim 52

An ink set as set forth in claim 31 , comprising a first color ink and a second color ink of the same color tone as the first color ink, wherein the absorbance at a maximum absorption wavelength in the visible light region of the first color ink is greater than the absorbance at a maximum absorption wavelength in the visible light region of the second color ink.

Claim 53

The recording unit according to claim 42 , wherein a magenta ink is used which contains at least one coloring material represented by the general formula (I): (wherein R 1 represents an alkoxy group, a substituted alkoxy group, an aryl group, or a substituted aryl group; R 2 and R 4 independently represent a hydrogen atom, an alkyl group, or a substituted alkyl group; R 3 represents a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxy group, a substituted alkoxy group, an aryloxy group, a substituted aryloxy group, or an halogen atom; X 1 represents a carboxyl group or a salt thereof or a sulfonic group or a substituted group of a salt thereof; and n represents an integer of 1 to 2).

Claim 54

The recording unit according to claim 42 , wherein a magenta ink is used which contains at least one of a coloring material of the general formula (I), a coloring material of the general formula (II), the general formula (III), and a coloring material of a xanthene structure: (wherein R 1 represents an alkoxy group, a substituted alkoxy group, an aryl group, or a substituted aryl group; R 2 and R 4 independently represent a hydrogen atom, an alkyl group, or a substituted alkyl group; R 3 represents a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxy group, a substituted alkoxy group, an aryloxy group, a substituted aryloxy group, or an halogen atom; X 1 represents a carboxyl group or a salt thereof or a sulfonic group or a substituted group of a salt thereof; and n represents an integer of 1 to 2); (wherein Ar 1 represents a group having an aryl group having at least one substituent selected from a carboxyl group or a salt thereof and a sulfonic group or a salt thereof, or a substituted or unsubstituted alkyl group: Ar 2 represents an acetyl group, a benzoyl group, a 1,3,5-triazine derivative, SO 2 —C 6 H 5 group, or SO 2 —C 6 H 4 —CH 3 group; and M 2 and M 3 are counterions and independently represent an alkali metal, ammonium or organic ammonium); and (wherein Ar 3 and Ar 4 independently represent an aryl group or a substituted aryl group and at least one of Ar 3 and Ar 4 has a substituent of a carboxyl group or a salt thereof, or a sulfonic group or a salt thereof; M is a counterion and represents an alkali metal, ammonium or organic ammonium; R 5 represents 1,3,5-triazine or a 1,3,5-triazine derivative; R 6 and R 7 independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group, or a substituted aralkyl group, or an atomic group which together with the N forms a perhydroxyazine ring: and L represents a divalent organic linking group).

Claim 55

The recording unit according to claim 42 , wherein as the color ink, a cyan ink is used which contains at least one coloring material having a copper phthalocyanine structure.

Claim 56

The recording unit according to claim 42 , wherein as the color ink, a cyan ink is used which contains Direct Blue 199 as the coloring material.

Claim 57

The recording unit according to claim 42 , wherein as the coloring material of the yellow ink, Direct Yellow 132 is used.

Claim 58

The recording unit according to claim 31 , wherein the coloring material of the color ink is a pigment.

Claim 59

The recording unit according to claim 31 , wherein the liquid flow path of the ink jet head part has a bubble generating region for generating a bubble in the ink in the liquid flow path and a movable member which is provided facing the bubble generating region and moves in accordance with the growth of the bubble.

Claim 60

The recording unit according to claim 57 , wherein the liquid flow path further has a regulating part for regulating the movement of the movable member in accordance with the growth of the bubble such that the movable member moves to substantially contact the regulating part, thereby substantially separating the liquid flow path with regard to a direction of flow of the ink to the discharge port.

Claim 61

The recording unit according to claim 57 , wherein a free end of the movable member is located substantially at a central part of the bubble generating region.

Claim 62

An image recording apparatus comprising the recording unit as set forth in claims 31 to 59 .