WO2020174940A1

WO2020174940A1 - Ink composition, ink-jet cartridge containing ink composition, and ink-jet device including mounted ink-jet cartridge

Info

Publication number: WO2020174940A1
Application number: PCT/JP2020/001983
Authority: WO
Inventors: 智祐勝山; 昭夫那須
Original assignee: 株式会社資生堂
Priority date: 2019-02-28
Filing date: 2020-01-21
Publication date: 2020-09-03
Also published as: CN113439028A; CN113439028B; JPWO2020174940A1; TW202039712A

Abstract

Provided is an ink composition which has a low viscosity and, despite this, is less apt to suffer sedimentation and has excellent hiding properties.　The ink composition of the present invention comprises titanium oxide particles and a dispersion medium and has a viscosity, as measured at a shear rate of 1,000 /s, of 100 mPa·s or less. The titanium oxide particles are secondary-structure particles which are each composed of a plurality of primary-structure particles connected to each other and have surface projections. The titanium oxide particles have a particle diameter of 150-500 nm in terms of equivalent circular diameter.

Description

\¥02020/174940 1 (: 17 2020/001983

Specification

Title of invention:

Ink composition, ink jet cartridge containing the ink composition, and inkjet device equipped with an inkjet cartridge

Technical field

The present disclosure relates to an ink composition, an ink jet cartridge containing the ink composition, and an ink jet device equipped with an ink jet cartridge.

Background technology

[0002] In recent years, for example, inkjet printers have been required not only to print on white paper but also to print on recording media such as black paper. When printing is performed on such a recording medium, an ink containing pigment-grade titanium oxide having a hiding power is generally used.

[0003]Patent Document 1 discloses a water-based ink for ink jet recording containing rutile type titanium oxide and a polymer dispersant, which can be easily redispersed by simple stirring even if titanium oxide precipitates. The polymer dispersant contains 72% by mass or more of structural units derived from at least one anionic group-containing monomer selected from acrylic acid, methacrylic acid, maleic acid, and sulfonic acid group-containing vinyl monomer, The rutile type titanium oxide has an average primary particle size of 100

Or more and 600 or less, the weight average molecular weight of the polymer dispersant is 300 or more,

Disclosed is a water-based ink for inkjet recording, in which the content of the polymer dispersant is 50 or less, and is 1% by mass or more and 7% by mass or less based on the titanium oxide.

[0004] Patent Documents 2 to 5 disclose the use of straw-bundle-shaped, strip-shaped, fan-shaped, and the like titanium oxide particles in high-viscosity cosmetics.

Prior art documents

Patent literature \¥02020/174940 2 (¥171?2020/001983

Patent Document 1: Japanese Patent Laid-Open No. 2 017 7-0 7 5 3 0 2

Patent Document 2: Patent No. 5 0 9 6 3 8 3 Publication

Patent Document 3: Japanese Patent Laid-Open No. 20 1 4 _ 8 4 2 5 1

Patent Document 4: Patent No. 4 6 8 4 9 7 0 Publication

Patent Document 5: Patent No. 6 2 5 8 4 6 2 Publication

Summary of the invention

Problems to be Solved by the Invention

[0006] When the pigment in the ink is aggregated or settled, for example, in a general ink jet printer, the ink cannot be ejected or the usable life of the ink cartridge is shortened. Resulting in. Among them, pigment-grade titanium oxide used for white ink has a large specific gravity and easily precipitates at a low viscosity like general ink for inks. As described in 1, it was necessary to agitate the ink before using it, or to use a large-scale device equipped with a mechanism that constantly circulates the ink.

[0007] Therefore, the subject of the present disclosure is to provide an ink composition that is hard to settle even at low viscosity and is excellent in hiding power.

Means for solving the problem

[0008] Aspect 1>

An ink composition containing titanium oxide particles and a dispersion medium, the viscosity at a shear rate of 100/3 is 100 0 01 3 3 or less, the titanium oxide particles, a plurality of primary A secondary structure particle having a surface protruding shape formed by connecting structures, and

The area circle equivalent particle diameter of the titanium oxide particles is 150 nm to 500 nm.

Ink composition.

á Mode 2>

The shape of the secondary structure is selected from needle-like, granular, spindle-like, strip-like, and rod-like. \¥02020/174940 3 卩 (: 171?2020/001983

The composition according to embodiment 1, which is at least one selected from the group consisting of:

á Mode 3>

The apparent bulk density of the titanium oxide particles is:

The composition according to aspect 1 or 2.

Aspect 4>

4. The composition according to any one of aspects 1 to 3, wherein the titanium oxide particles are rutile type titanium oxide particles.

Aspect 5>

The composition according to any one of aspects 1 to 4, further containing a dispersant. Aspect 6>

The composition according to any one of aspects 1 to 5, wherein the titanium oxide particles exhibit a color difference of 35.0 or less in a hiding property test.

á Mode 7>

7. The composition according to any one of aspects 1 to 6, wherein the dispersion medium contains water.

Aspect 8>

The composition according to any one of aspects 1 to 7, which is for an ink jet.

Aspect 9>

The composition according to any one of aspects 1 to 8, which is applied to the skin.

á Mode 1 ○>

An ink jet cartridge containing the composition according to any one of aspects 1 to 9.

Aspect 1 1>

An absorber for absorbing and holding ink, and

The ink cartridge according to aspect 10, wherein at least a part of the ink composition is held by the absorber.

Aspect 1 2>

The ink jet cartridge according to Aspect 10 or 11, wherein the ink jet droplet discharge system is a thermal system. \¥02020/174940 4 卩 (: 171?2020/001983

Aspect 1 3>

Aspect Inkjet device equipped with the ink jet cartridge according to any one of Aspects 10 to 12.

Aspect 1 4>

The device according to embodiment 13, wherein the ink composition is applied to the skin. Aspect 1 5>

An ink composition containing titanium oxide particles and a dispersion medium, the viscosity at a shear rate of 1/3 is 100 0 0 01 3 3 or less,

The viscosity at a shear rate of 100/3 is 100 001 3 3 or less, and the titanium oxide particles have an area circle equivalent particle diameter of 150 nm to 500 n, and

Ink composition.

Effect of the invention

[0009] According to the present disclosure, it is possible to provide an ink composition that is difficult to settle even at low viscosity and is excellent in hiding power.

Brief description of the drawings

[0010] [FIG. 1] A transmission electron microscopic photograph of unsintered titanium oxide particles used in one embodiment of the present disclosure.

FIG. 2 is a transmission electron microscopic photograph of fired titanium oxide particles used in another embodiment of the present disclosure.

FIG. 3 is a transmission electron micrograph of calcined titanium oxide particles having a surface coating layer used in yet another embodiment of the present disclosure.

MODE FOR CARRYING OUT THE INVENTION

[001 1] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments and can be variously modified and implemented within the scope of the gist of the invention.

[0012] An ink composition according to an embodiment of the present disclosure contains titanium oxide particles and a dispersion medium, has a viscosity at a shear rate of 100/3 and is 100 or less, and \¥02020/174940 5 ((171?2020/001983

The titanium particles are secondary structure particles having a surface protruding shape composed of a plurality of linked primary structures, and the titanium oxide particles have an area circle equivalent particle diameter of

It is 1 5 0 1^0 1 to 5 0 0 1^111.

[0013] Although not limited by the principle, the action principle that the ink composition of the present disclosure is hard to settle even at low viscosity and is excellent in hiding property is considered to be as follows.

[0014] In general, as an indicator of the sedimentability of particles in a liquid medium, the Stokes equation shown in the following Equation 1 can be used:

[Number 1]

1811 where

Settling velocity, mouth, particle size,

Particle density, _|0† means medium density, 9 means gravitational acceleration, 7] means medium viscosity.

[0015] The average particle size of the pigment grade titanium oxide is about 0.3, and in the cosmetics, the crystalline system has a high refractive index and the rutile system which is advantageous in hiding power is used. The density of the rutile system is 4.2 7 ₉ / !_ (Mr. Seino, Titanium oxide, 1 991). The sedimentation speed is proportional to the square of the particle diameter and the difference in density, and is inversely proportional to the medium viscosity.For example, in a low-viscosity medium such as an aqueous dispersion medium, high-density pigment-grade titanium oxide particles are used. Easily settles. The sedimentation speed is proportional to the square of the particle size and the difference in density, and is inversely proportional to the medium viscosity.For example, in a medium of low viscosity such as ink for ink jet, pigment specific titanium oxide particles having high specific gravity are used. The child was easy to settle. Therefore, although such pigment-grade titanium oxide particles may be blended with a medium used in cosmetics having a relatively high viscosity, a physical dispersion means such as stirring and shaking is applied. Therefore, it could not be blended in a medium with low viscosity such as inkjet ink.

[0016] On the other hand, the titanium oxide particles of the present disclosure have an area-equivalent circle equivalent particle size of 150 nm to 500 mm, which is similar to that of the pigment-grade titanium oxide particles, and therefore has excellent concealing properties. \¥02020/174940 6 卩 (: 171?2020/001983

In addition, for example, it exhibits a morphology as shown in FIGS. 1 and 2, that is, a secondary structure particle having a surface protruding shape composed of a plurality of _ secondary structures linked together. Therefore, it is thought that the protruding shape on the surface causes the material to float softly even in a medium of low viscosity, making it more difficult to settle than pigment-grade titanium oxide particles.

Further, such titanium oxide particles have a unique apparent bulk density different from general pigment-grade titanium oxide particles. Therefore, it is considered that titanium oxide particles having such a unique apparent bulk density can exhibit the same action and effect.

[0018] In addition, it is considered that the ink composition containing the titanium oxide particles of the present disclosure has excellent coatability and is easy to apply overcoat, and thus can further improve the hiding property.

[0019] <<Ink composition>>

The ink composition of the present disclosure contains titanium oxide particles and a dispersion medium, and the viscosity at a shear rate of 100/3 is 100 or less. Such viscosity is, for example,

It can be measured by using a rheometer such as (8: 1: 0 门一 3 3 "made by the company"), and the shear rate of the object to be measured when measured at 3 2 ^° 〇, 1 atm 1 0 0 0 Viscosity at 3 o'clock can be specified to be 100 0 01 3 3 or less, 5 0 01 3 3 or less, or 1 0 01 8 3 or less, and 1 01 8 3 or more.

[0020] static置粘of the ink composition of the present disclosure, i.e., shear rate 0 3 as possible - at the near to ^1, for example, shear rate 1

Viscosity at 100,000 or less,

3 or less, and 1001 or more, 5001 3 or more, 10000 1 3 or more, 1500 1133 or more,

It can be defined as 3 or more. The static viscosity can also be measured using the rheometer described above under the conditions of 32 ^° and 1 atm.

[0021] á Titanium oxide particles ñ \¥02020/174940 7 卩(: 171?2020/001983

The titanium oxide particles of the present disclosure include:

And it has a particle size, the titanium oxide particles of the secondary structure particles having a surface protruding shape in which a plurality of primary structure is configured by connecting, and / or, 0.70 ₉ / 〇 ³ the following apparent bulk density Titanium oxide particles having can be used

The type of titanium oxide may be any of anatase type, rutile type, and brookite type, but rutile type titanium oxide is preferable from the viewpoint of hiding power.

[0023] (Area equivalent circle diameter)

The area equivalent circle diameter of titanium oxide particles is intended to mean, for example, the particle diameter when converted into circular particles having the same area as the projected area of titanium oxide particles observed with a transmission electron microscope. it can. The area circle equivalent particle diameter can be defined as the average value of 10 or more particles. The equivalent area circle diameter of the titanium oxide particles is more preferably from 150 nm to 450 n°!, from the viewpoint of hiding power, anti-sedimentation property, discharge property, etc.

40011111 is particularly preferable.

[0024] (Apparent bulk density)

The titanium oxide particles of the present disclosure have an apparent bulk density of 0.

Hereinafter, 〇. 65 ₉ / 〇 ³ or less, or 〇.

It is preferably 60 ³ or less. There is no particular lower limit to the apparent bulk density, but for example, 〇.

Above, 〇.

Top or 〇.35

It can be defined as ³ or more. The apparent bulk density can be obtained, for example, by using a specific volume tester as described later.

[0025] (Hiding power)

The titanium oxide particles of the present disclosure can have a color difference (ΔM) that is an index of the hiding property in the hiding property test described below, of 35.0 or less, 32.0 or less, or 30.0 or less. The lower limit of the color difference is not particularly limited, but can be specified to be, for example, 10.0 or more, 12.0 or more, or 15.0 or more. \¥02020/174940 8 卩 (: 171?2020/001983

[0026] (Specific surface area)

Titanium oxide particles of the present disclosure, concealing property, in view of耐沈descending resistance, specific surface area, 1 0 ^2/9 or more, 1 5 ^2/9 or more, 20_Rei_1 ^2/9 or more, or 30_Rei_1 ² / is preferably 9 or more, also 1 50_Rei_1 ^2/9 or less, 1 20_Rei_1 ^2/9 or less, or 1

The following is preferable. The specific surface area of titanium oxide can be determined, for example, by the Mitsumi method.

[0027] (Crystallite diameter)

The titanium oxide particles of the present disclosure have a size of 8.5 n or more, 9.0 nm or more, or 9.

Can have a crystallite size of 5 n or more, and 35.0 n

Hereafter, the crystallite size may be 30.0 or less, or 25.0 or less. The crystallite size of titanium oxide particles can be measured by a general X-ray diffraction method.

[0028] (Shape)

As the titanium oxide particles of the present disclosure, secondary structure particles having a surface protruding shape formed by connecting a plurality of primary structures can be used.

[0029] The shape of the secondary structure may be any shape as long as sedimentation resistance and concealment performance can be obtained, and is not limited to the following, for example, needle-shaped, granular, spindle-shaped, strip-shaped, And at least one selected from rod-like shapes, and among them, needle-like, granular, or rod-like shapes as shown in FIGS. 1 to 3 are preferable.

[0030] — The secondary structure may be connected so as to have a shape protruding on the surface of the secondary structure particle, and the connection structure is not particularly limited, but the primary structure is, for example, a fan-shaped structure. It may be connected in a radial or random manner, and in particular, it is preferably connected in a radial manner from the viewpoint of sedimentation resistance and concealment. Such a connection is made, for example, by aggregating or sintering the primary structures with each other, and by aggregating or sintering the primary structures with each other, a secondary structure can be formed.

[0031] (Surface coating layer) \¥02020/174940 9 ((171?2020/001983

The surface of the titanium oxide particles may be covered with one or more inorganic materials other than titanium oxide. Such inorganic materials are not limited to the following, but include, for example, a component containing an element selected from aluminum, silicon, zinc, zirconium, iron, cerium and tin, for example, a hydrous oxide of such an element or An oxide is mentioned. Of these, silicon oxide and aluminum oxide are preferable. Titanium oxide particles provided with a surface coating layer have titanium oxide particles as a main component from the viewpoint of concealment, that is, 50% by mass or more, 60% by mass or more, or 70% by mass or more of the particles are contained. It is preferably a titanium oxide component. The ratio of the surface coating layer in the titanium oxide particles is based on the mass of the titanium oxide particles,

It can be 50 mass% or less, 40 mass% or less, or 30 mass% or less, and 1 mass% or more, 3 mass% or more, 5 mass% or more, 7 mass% or more, 10 mass. % Or 15% by mass or more.

By coating the surface of the titanium oxide particles with such an inorganic material, it is possible to reduce the shape change of the primary structure, particularly the shape change due to sintering. The reason why the shape change of the primary structure can be reduced is not clear, but by forming a coating layer made of an inorganic material different from titanium oxide on the surface of the primary structure made of titanium oxide, It is believed that this is because the sintering of sinter was hindered.

[0033] Further, hydroxyl groups are likely to be arranged on the surface of the surface coating layer made of an inorganic material. As a result, the compatibility between the aqueous dispersion medium and the titanium oxide particles is improved, so that the dispersibility in the aqueous dispersion medium can be improved.

[0034] The titanium oxide particles whose surface is coated with an inorganic material may be used as they are in an unbaked state or may be used in a baked state, but the concealing property and the durability of the surface coating layer may be used. From the viewpoint of properties, it is preferable to use the one in a fired state. When calcined, the porosity of titanium oxide particles, especially the porosity in the vicinity of the core inside the titanium oxide particles where surface coating is difficult to occur, can be reduced compared to unsintered surface-coated titanium oxide particles. We believe that it can improve the concealment performance. Also, the coating layer on the surface of titanium oxide particles is \¥02020/174940 10 ((171?2020/001983

It is believed that the formation improves the binding force with the titanium oxide particles and prevents the coating layer from peeling off, so that the durability is also improved compared to the unbaked coating layer.

[0035] (Amount blended)

The content of the titanium oxide particles of the present disclosure can be appropriately adjusted according to the intended use, and is not limited to the following. For example, in the ink composition, 5% by mass or more, 10% by mass or more , Or 20% by mass or more, and 30% by mass or less, 27% by mass or less, or 25% by mass or less.

[0036] Dispersion medium

The dispersion medium is not particularly limited as long as it can disperse the titanium oxide particles, and one or more known dispersion media such as an organic dispersion medium and an aqueous dispersion medium can be used. Above all, it is preferable to use an environmentally friendly aqueous dispersion medium, which is often used in ink jet printers and the like. Examples of the aqueous dispersion medium include water, various alcohols such as lower alcohols and polyhydric alcohols, or a mixture thereof.

The [0037] lower alcohol, e.g., ethanol, propanol, isopropanol, isobutyl alcohol, 1; - butyl alcohol ^_ le, and the like.

[0038] Examples of the polyhydric alcohol include dihydric alcohols (for example, ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, tetramethylene glycol, 2, 3-butylene glycol, pentamethylene glycol, 2-butene-1,4-diol, hexylene glycol, octylene glycol, etc.); trivalent alcohol (eg, glycerin, trimethylolpropane, etc.); tetravalent alcohol (eg, 1,2,6-Pentaerythritol such as hexanetriol, etc.); Pentahydric alcohols (eg, xylitol, etc.); Hexavalent alcohols (eg, sorbitol, mannitol, etc.); Polyhydric alcohol polymers (eg, , Diethylene glycol, dipropylene glycol, triethylene glycol, polypropylene glycol, tetraethylene glycol, diglycerin, polyethylene glycol, triglycerin, tetraglycerin, poly \¥02020/174940 11 (:171?2020/001983 Glycerin, etc.); Divalent alcohol alkyl ethers (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol) Monobutyl ether, Ethylene glycol monophenyl ether, Ethylene glycol monohexyl ether, Ethylene glycol mono 2-methylhexyl ether, Ethylene glycol isoamyl ether, Ethylene glycol benzyl ether, Ethylene glycol isopropyl ether, Ethylene glycol dimethyl ether, Ethylene glycol ethyl ether, Ethylene glycol dibutyl ether, etc.; Dihydric alcohols Alkyl ethers (eg, ethylene glycol monomethyl ether, ethylene glycol mono) Ethyl ether, Jetylene glycol monopeptyl ether, Jetylene glycol dimethyl ether, Jetylene glycol Jetil ether, Jetylene glycol pettyl ether, Jetylene glycol Methyl ethyl ether, Tritylene glycol Monomethyl ether, Triethylene glycol monoethyl ether, Propylene glycol monomethyl ether, Propylene glycol monoethyl ether, Propylene glycol monoptyl ether, Propylene glycol isopropyl ether, Dipropylene glycol methyl Ether, dipropylene glycol ethyl ether, dipropylene glycol pettyl ether, etc.); dihydric alcohol ether ester (eg, ethylene glycol monomethyl ether acetate, ethyl ether, ethylene glycol monoethyl acetate, Ethylene Glycol Monobutyl Ether Acetate, Ethylene Glycol Monophenyl Ether Acetate, Ethylene Glycol Diadibate, Ethylene Glycol Disuccinate, Jetylene Glycol Monoethyl Ether Acetate, Getylene Glycol Monoptyl Ether Ter-acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol Monophenyl ether acetate, etc.; Glycerin monoalkyl ether (eg, xyl alcohol, cerakil alcohol, bacillua \¥02020/174940 12 boxes (: 171?2020/001983

Sugar alcohol (eg, sorbitol, maltitol, maltitol triose, mannitol, sucrose, erythritol, glucose, fructose, starch-decomposing sugar, maltose, xylitolose, starch-decomposing sugar-reducing alcohol) Etc.); Glysolid; Tetrahydrofurfurfuryl alcohol; 〇〇-Pentane erythritol ether, polyglycerin, etc.

[0039] á Optional ingredients ñ

The ink compositions of the present disclosure, in a range not impairing the effects of the present disclosure, other ingredients, such as pigments other than titanium oxide, dyes, esters, humectants, water-soluble high-molecular, oil, higher alcohol ^_ le, binder ^_ , dispersants, various salt components, thickeners, surface tension lowering agents such as various surfactants, film forming agents, UV absorbers, UV scattering agents, sequestering agents, amino acids, organic amines, polymer emulsions, 1 ^to 1 regulator, skin nutrition agent, vitamin agent, antioxidant, antioxidant aid, fragrance, antiseptic, anti-inflammatory agent, anti-inflammatory agent, whitening agent, activator, antiseborrheic agent, various crude drug extracts, A drug or the like can be appropriately blended as necessary. Since the titanium oxide particles of the present disclosure have excellent sedimentation resistance, it is not necessary to use a dispersant, but when a dispersant such as a polymer electrolyte is used, the sedimentation resistance can be further improved. ..

[0040] <<Application of ink composition>>

The ink composition of the present disclosure includes, for example, paints for automobiles, painted steel plates, building materials, cans, printing agents for dyeing fibers, inks such as gravure ink, flexo ink, ball pens, fountain pens, signature pens, markers, and correction pens. Examples include inks for writing instruments such as inks, inks for ink jets such as thermal methods and piezo methods, dispersions for color filters used in LCD TVs, laptop computers, etc., but are not limited to these applications. Not a thing.

[0041] Among them, the ink composition of the present disclosure is excellent in sedimentation resistance at low viscosity. \¥02020/174940 13 ((171?2020/001983

Therefore, it can be suitably used as an ink for inkjet, which is generally low in viscosity. When the ink composition of the present disclosure is used as an ink for inkjet, it does not require a unit such as stirring or shaking, and specifically,

It can exhibit the function of ejecting ink for 1 day or more, 7 days or more, or 30 days or more. The following describes the usage as an ink for inkjet.

[0042] "Inkjet device"

The ink composition of the present disclosure can be used in a known ink jet device in which an ink jet cartridge for containing and discharging ink is detachably mounted.

The ink jet device can be used not only for a general recording medium such as paper but also for human skin.

[0044] When the ink jet device is used for human skin, the ink composition of the present disclosure may be appropriately blended with an arbitrary component to prepare an ink composition as a skin external preparation, a cosmetic, a cosmetic, or the like. it can. Among them, the ink composition of the present disclosure has excellent concealing properties, and therefore, it is preferable to use it appropriately as a concealer for concealing spots, freckles, and the like on the skin by appropriately adjusting it to the skin color and the like.

[0045] á Inkjet cartridge ñ

The ink jet cartridge includes an ink chamber that stores the ink composition of the present disclosure as ink for ink jetting, and an ejection element.

[0046] The ink chamber has an ejection port for ejecting ink. The ink chamber may further include an absorber that absorbs and holds the ink. As the absorbent body, for example, a porous body such as a fiber, a non-woven fabric or a sponge can be used.

The ejection element is an element for ejecting a droplet of the ink composition from the ejection port, and may be either a thermal type or a piezo type, but a thermal type is preferable. For example, in the case of a thermal ink jet, the ejection element can be, for example, a heater, and in the case of a piezo ink jet, the ejection element can be, for example, a piezo element and a diaphragm. \¥02020/174940 14 ((171?2020/001983

[0048] <<Method for producing titanium oxide particles>>

The method for producing titanium oxide particles of the present disclosure is not particularly limited, but for example, for titanium oxide particles of secondary structure particles in which needle-like primary structures as shown in FIG. The description in 4 can be referred to. Specifically, for example, by using titanyl sulfate solution as titanium oxide-forming solution, ortho titanate titanyl sulfate solution obtained by alkaline neutralization of at 1 0 ° 〇 temperatures below, 1 0 ^° 〇 less It can be obtained by adding hydrochloric acid at the temperature of 1 to completely dissolve orthotitanic acid, and then heating to perform hydrolysis. Ding I 〇 ₂ concentration at that time, 5 0-1 4 0 9 / 1_, preferably 6 0-1 2 0 9 / 1_, hydrochloric acid concentration is 7 0-1 7 0 ₉ /! _, Preferably is 8 0-1 6 0 ₉ / 1_. The temperature of hydrolysis, 2 5 to 6 0 ^° 〇, preferably 3 0 to 5 5 ^° 〇.

[0049] Further, the titanium oxide particles of the present disclosure are hydrolyzed using a solution of titanium tetrachloride, or a solution of an alkali salt of titanic acid obtained by treating metatitanic acid with an alkali in hydrochloric acid, in addition to orthotitanic acid. You can also get

[0050] The obtained titanium oxide particles are fired using, for example, a general firing furnace such as a matsufuru furnace or a mouth tally kiln to obtain a granular or rod-shaped primary structure as shown in Fig. 2. Titanium oxide particles having linked secondary structure particles can be obtained. Here, the firing temperature can be set to, for example, 500 to 800 ^° , and more preferably, 55 to 75500.

[0051] In addition, for titanium oxide particles of secondary structure particles formed by connecting primary structures such as rod-shaped and strip-shaped, for example, the method as described in Patent Document 3 is appropriately used, It can be obtained by firing if necessary.

[0052] á Surface coating method of titanium oxide particles ñ

The surface of the titanium oxide particles can be coated with an inorganic material in order to improve the dispersibility in a low-viscosity dispersion medium and to reduce the shape change of the secondary structure due to sintering. The titanium oxide particles surface-coated with the inorganic material may be used as they are, or may be further calcined at a temperature of, for example, 500 to 800 ^° . When titanium oxide particles that are not surface-coated are fired, they generally have the shape shown in Figure 1. \\02020/174940 15 ((171?2020/001983

The shape changes to the shape shown in Fig. 2. However, surprisingly, when the titanium oxide particles surface-coated with the inorganic material are fired, the shape of the titanium oxide particles can substantially maintain the shape of FIG. 1 as shown in FIG.

[0053] There is no particular limitation on the method of coating the surface of the titanium oxide particles. For example, the titanium oxide particles prepared as described above are added to ion-exchanged water to prepare a mixed solution (slurry). Next, an inorganic material coating liquid consisting of an aqueous solution of sodium silicate was added to the slurry while maintaining the temperature at about 70 ^° C and slowly added with stirring, and after stirring for a predetermined time, dilute hydrochloric acid, dilute sulfuric acid, or other acid was added. Add 1 ^to 1 to adjust to about 5.0 to 8.0. By performing this operation twice or more, the layer constitution or the coating amount of the surface coating layer can be adjusted. In addition, the coating amount of the surface coating layer can also be adjusted by adjusting the composition, concentration and blending amount of the inorganic material coating liquid.

[0054] The obtained mixed solution is filtered, washed with water, dried, and optionally calcined using a general calcining furnace such as a matsuful furnace or a mouth tarry kiln to obtain a shape as shown in Fig. 3. Surface-coated calcined titanium oxide particles can be obtained. Baking can reduce the porosity of the titanium oxide particles, in particular, the porosity of the core portion of the titanium oxide particles, which is difficult to be surface-coated, so that the hiding performance can be improved.

[0055] In the case of firing, the firing temperature may be, for example, 500 to 800 ^° 〇, more preferably 5500 to 750 ^° 〇, and The baking time can be 0.5 to 2.0 hours, and more preferably 1.0 to 1.5 hours. By adjusting the material of the surface coating layer, the baking temperature, the baking time, etc., it is possible to control the properties such as the surface protruding shape retention of the titanium oxide particles subjected to the surface coating and the baking treatment, the sedimentation resistance, and the hiding property. it can.

Example

[0056] Hereinafter, the present disclosure will be described in more detail with reference to Examples, but the present disclosure is not limited thereto. In addition, hereinafter, unless otherwise specified, the compounding amount is shown by mass %. \¥02020/174940 16 box (: 171?2020/001983

[0057] <<Examples! ~ 3 and Comparative Examples 1 to 2 >>

The titanium oxide particles obtained by the production method shown below were evaluated for area circle equivalent particle diameter, specific surface area, apparent bulk density, hiding power, and crystallite diameter. Further, the viscosity and the ejection property of the ink composition obtained by the formulation and the manufacturing method of Table 1 shown below were evaluated.

[0058] á Evaluation of titanium oxide particles ñ

Various evaluations shown below were carried out on the prepared titanium oxide particles, and the results are summarized in Table 1.

(Evaluation of particle diameter equivalent to area circle)

The area equivalent circle diameter is 100,000 times as large as the average value of 100 particles of titanium oxide using a transmission electron microscope! I 7100 type (manufactured by Hiritsu High Technology Co., Ltd.). evaluated.

[0060] (Evaluation of specific surface area)

For specific surface area,

1 — 1 208 (manufactured by IV! 〇 un I 060 h company) Evaluated by the Mitsumi method.

(Evaluation of apparent bulk density)

Titanium oxide particles are put into a 20 !_ specific volume test tube and weighed about 10 !_. Using a specific volume tester, Tei 10 Miho 01 (manufactured by Yamaguchi Mica Co., Ltd.), the weighed test tube was tapped 200 times, the volume was measured, and the apparent bulk density was calculated. The apparent bulk density was evaluated according to the following criteria.

(Evaluation of concealment)

A slurry was prepared by mixing and stirring titanium oxide particles in a nitrocellulose rattle so that the ratio of titanium oxide particles was 5% by mass. Then, on the black-and-white concealment ratio test paper described in “3 <5400,

The slurry was applied with an applicator and dried to obtain a test sample. Obtained The color of the test sample was measured with a CM-2600 d (manufactured by Konica Minolta Co., Ltd.), which is a spectrophotometer. The color difference (AE) in the H unter Lab color space was calculated by the following Equation 2, and the hiding property was evaluated according to the following criteria:

[Number 2]

AE = / (L1-L2) ² + (al-a2) ² + (bl-b2) ² Equation ₂

[0064] It should be noted that the larger the AE, the lower the hiding power, and the smaller the AE, the higher the hiding power.

[0065] A: AE £35

B: 35<AE £60

C: 60<△ E

(Evaluation of crystallite size)

The crystallite size of the titanium oxide particles was measured with an X-ray diffractometer (Geiger fIex, manufactured by Rigaku Denki Co., Ltd.), and the Scherrer's formula was applied to calculate the average crystallite size.

[0067] á Evaluation of ink composition ñ

Various evaluations shown below were performed on the prepared ink composition, and the results are summarized in Table 1.

(Evaluation of viscosity)

The viscosity was evaluated using MCR-302 (manufactured by Anton-Paar). The viscosity is the viscosity at a shear rate of 1/s or at a shear rate of 1000/s of the object to be measured when measured at 32 ^° C and 1 atm. In Table 1, the viscosity at a shear rate of 1/s is described as "static viscosity" and the viscosity at a shear rate of 1 000/s is described as "shear viscosity".

(Evaluation of ejection property)

Thermal ink jet cartridge with an absorber in the ink chamber \¥02020/174940 18 卩(: 171?2020/001983

— Lett Packard) was filled with the prepared ink composition and printed on black paper using an ink jet device (made by HYURET Packard), which was equipped with such a force cartridge. The dischargeability was evaluated. The ejection property test was performed 1 hour, 24 hours, and 1 month (30 days) after the ink composition was filled in the ink cartridge.

[0070] Eight: White characters could be printed.

Tomomi: Slightly faint or missing lines occurred, but white characters were sufficiently printed.

0: Clear fading or line omission occurred in white characters.

0: White characters could not be printed.

[0071] Example 1>

A solution of titanyl sulfate obtained by dissolving washed metatitanic acid with sulfuric acid was added to 1609/

It was slowly dropped into the sodium carbonate solution of !_ so that the solution temperature did not exceed 10 ° 〇, and when 1 ^to 1 reached 10 0.0, titanyl sulfate was stopped dripping. The white precipitate of orthotitanic acid obtained by this neutralization was filtered and thoroughly washed.

[0072] Then, the cooled orthotitanic acid cake was added to concentrated hydrochloric acid while cooling to 10 ^° C or less, and stirred until the orthotitanic acid was completely dissolved. Thereafter, Ding丨〇 ₂ concentration 6 0 9 / -, adjusted to hydrochloric acid concentration of 8 0 9 / 1_, warmed while stirring to 5 5 ° 〇 combined liquid temperature, 2 0 Hydrolysis was performed by stirring for a time. The obtained rutile-type titanium oxide was neutralized, washed, and dried to oxidize in the form of secondary structure particles composed of needle-like primary structures linked together as shown in Fig. 1. Titanium particles 8 were obtained.

[0073] The obtained titanium oxide particles 8, a dispersant, a polyhydric alcohol and a salt were added to ion-exchanged water at a blending ratio shown in Table 1 below, and ultrasonic vibration was applied to prepare an ink composition. ..

[0074] Example 2>

Titanium oxide particles 8 prepared by the same method as in Example 1 were calcined in a muffle furnace at 550° ◯ for 1 hour to obtain a granular or rod-shaped one as shown in FIG. \¥02020/174940 19 卩(: 171?2020/001983

An ink composition was prepared in the same manner as in Example 1 except that titanium oxide particles that were in the form of secondary structure particles constituted by connecting the following structures were used.

[0075] Example 3>

Titanium oxide particles 8 prepared by the same method as in Example 1 were dispersed in ion-exchanged water to prepare a dispersion liquid. Then, to the dispersion liquid containing titanium oxide particles, 3丨〇 ₂ 5 wt% of sodium silicate solution was added with stirring as, after 1 hour stirring, ^to 1 by the slow addition of dilute hydrochloric acid 1 Was adjusted to 5.0. Wherein the amount of sodium silicate solution, based on the weight of the titanium oxide particles eighth before coating, was used in an amount of 3丨〇 ₂ coating is 3 wt%.

[0076] Next, the obtained dispersion, eight I ₂ 〇 ₃ as 7 wt% of aluminate sodium solution was further added, after 1 hour stirring, with dilute hydrochloric acid! ^~ 1 6. Adjusted to 5. Wherein the amount of sodium aluminate solution, based on the weight of the titanium oxide particles eighth before coating, was used in an amount of eight I ₂ 〇 ₃ coating is 6% by weight.

The obtained dispersion was filtered, washed with water, dried, and calcined at 550° C. for 1 hour in a matsufur furnace to obtain surface-coated rutile type titanium oxide ◯. As shown in FIG. 3, the particle shape of the obtained titanium oxide 0 was almost the same as the particle shape in Example 1 even after firing.

An ink composition was prepared in the same manner as in Example 1 except that the obtained titanium oxide was used.

[0079] á Comparative Example 1>

Ink was prepared in the same manner as in Example 1, except that pigment-grade rutile titanium oxide particles, which had an irregular shape, were used. A composition was prepared.

[0080] Comparative Example 2>

An ink composition was prepared in the same manner as in Example 1 except that fine particle type (needle-shaped) rutile type titanium oxide particles, Ding-Cho 05 (8) (manufactured by Ishihara Sangyo Co., Ltd.) were used. \¥02020/174940 20 €!71?2020/001983

[0081] [Table 1]

[0082] á Result ñ

As is clear from the results in Table 1, in the ink composition of Comparative Example 1 using conventional pigment-grade titanium oxide particles, the ink nozzles were immediately clogged due to the sedimentation of the titanium oxide particles, and thus ink cartridge preparation was performed. Ink could not be ejected after 1 hour.

[0083] The ink composition of Comparative Example 2 had a static viscosity of

3 and Example 1 to

It is larger than the static viscosity of the ink composition of No. 3. We believe that this is due to the small particle size of the titanium oxide particles. Since the ink composition of Comparative Example 2 having such a high static viscosity is difficult to discharge, clear blur or line omission has already occurred in white characters 1 hour after ink cartridge production, and after 24 hours, The character could not be printed. In addition, the ink composition of Comparative Example 2 exhibits sufficient hiding power because the titanium oxide particles have a small particle size. \¥02020/174940 21 卩 (: 171?2020/001983

I couldn't do it either.

[0084] On the other hand, the ink compositions of Examples 1 to 3 using the titanium oxide particles having a specific size and shape are excellent in hiding power and, in addition, have excellent ink jetting property after 24 hours. It was confirmed to be excellent. Above all, it was confirmed that the ink composition of Example 3 using the surface-coated titanium oxide particles was excellent in the ink jetting property even after one month.

Claims

\¥02020/174940 22 卩(:171?2020/001983 Claims

[Claim 1] An ink composition containing titanium oxide particles and a dispersion medium, wherein the viscosity at a shear rate of 100/3 is 100 001 3 3 or less, and the titanium oxide particles are Is a secondary structure particle having a surface protruding shape constituted by connecting a plurality of primary structures, and, the area circle equivalent particle diameter of the titanium oxide particles, 150 nm ~ 500 n 111,

Ink composition.

[Claim 2] The composition according to claim 1, wherein the shape of the primary structure is at least one selected from a needle shape, a granular shape, a spindle shape, a strip shape, and a rod shape.

[Claim 3] The apparent bulk density of the titanium oxide particles is 0.70.

The composition according to claim 1 or 2, which is ³ or less.

4. The titanium oxide particles are rutile type titanium oxide particles.

The composition according to any one of 1 to 3.

[Claim 5] The composition according to any one of claims 1 to 4, further comprising a dispersant.

6. The composition according to any one of claims 1 to 5, wherein the titanium oxide particles exhibit a color difference of 35.0 or less in a hiding test.

[Claim 7] The composition according to any one of claims 1 to 6, wherein the dispersion medium contains water.

[Claim 8] The composition according to any one of claims 1 to 7, which is for an inkjet.

[Claim 9] The composition according to any one of claims 1 to 8, which is applied to the skin.

[Claim 10] An ink jet cartridge containing the composition according to any one of claims 1 to 9.

[Claim 11] Including an absorber for absorbing and holding ink, and

At least a part of the ink composition is held by the absorber. \¥02020/174940 23 卩 (: 171?2020/001983

The ink jet cartridge according to claim 10.

[Claim 12] The ink jet cartridge according to claim 10 or 11, wherein the ink jet liquid droplet ejection method is a thermal method.

[Claim 13] An ink jet device comprising the ink jet cartridge according to any one of claims 10 to 12.

[Claim 14] The device according to claim 13, wherein the ink composition is applied to skin.

[15] An ink composition containing titanium oxide particles and a dispersion medium, wherein the viscosity at a shear rate of 1/3 is 100,000 or less, and the shear rate is 100,000. The viscosity at /3 is 100 0 01 3 3 or less, and

The titanium oxide particles have an area circle equivalent particle diameter of 150 nm to 500 n, and ◯.

Ink composition.