Ink jet recording apparatus and method of producing porous body

An ink jet recording apparatus comprising:

• an image forming unit that forms a first image containing a first liquid and a coloring material on an ink receiving medium;
• and
• a liquid absorbing member that includes a porous body, which is configured to be brought into contact with the first image so as to absorb at least a portion of the first liquid from the first image,
• wherein the porous body is a porous sheet in which a first layer, which is configured to be brought into contact with the first image, a second layer a including a second fiber a, a second layer b including a second fiber b, and a third layer including a third fiber are laminated in this order, and the first layer, the second layer a, the second layer b, and the third layer are porous layers,
• wherein an average fiber diameter of the second fiber b is larger than an average fiber diameter of the third fiber,
• wherein the second fiber a and the second fiber b have a core-in-sheath structure including a core structure forming a central axis and a sheath structure surrounding the core structure,
• wherein a softening temperature of a material for forming the sheath structure of the second fiber a is lower than any of a softening temperature of a material for forming the core structure of the second fiber a and a softening temperature of a material for forming the first layer,
• wherein a softening temperature of a material for forming the sheath structure of the second fiber b is lower than any of a softening temperature of a material for forming the core structure of the second fiber b and a softening temperature of a material for forming the third fiber, and
• wherein an average thickness of the sheath structure of the second fiber a is smaller than a thickness of the first layer.

An ink jet recording apparatus comprising:

• an image forming unit that forms a first image on an ink receiving medium by applying ink containing a first liquid and a coloring material;
• and
• a liquid absorbing member that includes a porous body, which is configured to be brought into contact with the first image so as to concentrate ink constituting the first image,
• wherein the porous body is a porous sheet in which a first layer, which is configured to be brought into contact with the first image, a second layer including a second fiber, and a third layer including a third fiber are laminated in this order, and the first layer, the second layer, and the third layer are porous layers,
• wherein an average fiber diameter of the second fiber is larger than an average fiber diameter of the third fiber,
• wherein the second fiber has a core-in-sheath structure including a core structure forming a central axis and a sheath structure surrounding the core structure,
• wherein a softening temperature of a material for forming the sheath structure is lower than any of a softening temperature of a material for forming the core structure, a softening temperature of a material for forming the first layer, and a softening temperature of a material for forming the third fiber, and
• wherein an average thickness of the sheath structure is smaller than a thickness of the first layer.

A method of producing a porous body used in an ink jet recording apparatus including:

• an image forming unit that forms a first image containing a first liquid and a coloring material on an ink receiving medium;
• and a liquid absorbing member that includes a porous body, which is configured to be brought into contact with the first image so as to absorb at least a portion of the first liquid from the first image, the method comprising:
• a step of heating a first layer, which is configured to be brought into contact with the first image, a second layer including a second fiber, and a third layer including a third fiber in a state of being laminated in this order so as to form a porous body including the first layer, the second layer, and the third layer,
• wherein the first layer, the second layer, and the third layer are porous layers,
• wherein an average fiber diameter of the second fiber is larger than an average fiber diameter of the third fiber,
• wherein the second fiber has a core-in-sheath structure including a core structure forming a central axis and a sheath structure surrounding the core structure, wherein a softening temperature of a material for forming the sheath structure is lower than any of a softening temperature of a material for forming the core structure, a softening temperature of a material for forming the first layer, and a softening
• temperature of a material for forming the third fiber, wherein an average thickness of the sheath structure is smaller than a thickness of the first layer, and
• wherein a temperature of the heating is equal to or higher than the softening temperature of the material for forming the sheath structure, and is equal to or lower than the softening temperature of the material for forming the core structure, the softening temperature of the material for forming the first layer, and the softening temperature of the material for forming the third fiber.

A method of producing a porous body used in an ink jet recording apparatus including:

• an image forming unit that forms a first image containing a first liquid and a coloring material on an ink receiving medium;
• and a liquid absorbing member that includes a porous body, which is configured to be brought into contact with the first image so as to absorb at least a portion of the first liquid from the first image, the method comprising:
• a step of heating a first layer, which is configured to be brought into contact with the first image, a second layer a including a second fiber a, a second layer b including a second fiber b, and a third layer including a third fiber in a state of being laminated in this order so as to form a porous body including the first layer, the second layer a, the second layer b, and the third layer,
• wherein the first layer, the second layer a, the second layer b, and the third layer are porous layers,
• wherein an average fiber diameter of the second fiber b is larger than an average fiber diameter of the third fiber,
• wherein the second fiber a and the second fiber b have a core-in-sheath structure including a core structure forming a central axis and a sheath structure surrounding the core structure,
• wherein a softening temperature of a material for forming the sheath structure of the second fiber a is lower than any of a softening temperature of a material for forming the core structure of the second fiber a and a softening temperature of a material for forming the first layer,
• wherein a softening temperature of a material for forming the sheath structure of the second fiber b is lower than any of a softening temperature of a material for forming the core structure of the second fiber b and a softening temperature of a material for forming the third fiber,
• wherein an average thickness of the sheath structure of the second fiber a is smaller than a thickness of the first layer, and
• wherein a temperature of the heating is equal to or higher than the softening temperature of the material for forming the sheath structure of the second fiber a and the second fiber b, and is equal to or lower than the softening temperature of the material for forming the core structure of the second fiber a and the second fiber b, the softening temperature of the material for forming the first layer, and the softening temperature of the material for forming the third fiber.

A porous body comprising, in stated order:

• a first layer;
• and
• a second layer including a second fiber,
• wherein the first layer and the second layer are porous layers,
• wherein the second fiber has a core-in-sheath structure including a core structure forming a central axis and a sheath structure surrounding the core structure,
• wherein a softening temperature of a material for forming the sheath structure is lower than any of a softening temperature of a material for forming the core structure and a softening temperature of a material for forming the first layer, and
• wherein an average thickness of the sheath structure is smaller than a thickness of the first layer.

A porous body comprising, in stated order:

• a first layer;
• a second layer a including a second fiber a;
• and
• a second layer b including a second fiber b,
• wherein the first layer, the second layer a, and the second layer b are porous layers,
• wherein the second fiber a and the second fiber b have a core-in-sheath structure including a core structure forming a central axis and a sheath structure surrounding the core structure,
• wherein a softening temperature of a material for forming the sheath structure of the second fiber a is lower than any of a softening temperature of a material for forming the core structure of the second fiber a and a softening temperature of a material for forming the first layer,
• wherein a softening temperature of a material for forming the sheath structure of the second fiber b is lower than a softening temperature of a material for forming the core structure of the second fiber b, and
• wherein an average thickness of the sheath structure is smaller than a thickness of the first layer.