JP2022128672A - Water-based ink composition for reversible thermochromic writing instruments and writing instrument - Google Patents

Abstract

To provide a water-based ink composition for reversible thermochromic writing instruments that can form thermochromic handwritten characters having excellent luster even on a medium of high brightness; can prevent a luster pigment contained in the handwritten characters from transferring onto a paper surface that the handwritten characters have contacted at the time of contact; and also allows proper removal of the luster pigment when the handwritten characters are thermally discolored by rubbing with a friction member or the like.SOLUTION: A reversible thermochromic water-based ink composition contains: a reversible thermochromic microcapsule pigment containing a reversible thermochromic composition composed of an electron-donating coloring organic compound, an electron-accepting compound, and a reaction medium for determining the temperature of coloration reaction of both compounds; resin-coated flaky metallic pigments; a pigment having a transparent base material coated with metal oxide; water; a thickener and a resin. The resin has a glass transition temperature (Tg value) of 0°C or lower.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a reversible thermochromic water-based ink composition for writing instruments and a writing instrument.

A reversible thermochromic microcapsule pigment, a luster pigment consisting of a resin-coated flaky metal pigment (lame pigment) and a transparent base material coated with a metal oxide (pearl pigment), and water and a reversible thermochromic water-based ink composition containing a thickener is known, and thermochromic handwriting that exhibits excellent metallic luster not only on black paper but also on high-brightness media such as white paper can be realized. (See Patent Document 1, for example).

JP 2019-189687 A

The handwriting made by the ink composition does not have sufficient fixation of the lame pigment, and when the paper comes into contact with the handwriting, the lame pigment of the handwriting is transferred to the surface of the paper that touches the handwriting, which sometimes weakens the luster of the handwriting. In addition, even if an attempt is made to remove the luster pigment while discoloring the handwriting by rubbing the handwriting with a friction member or the like, part of the pearl pigment is embedded in the gaps between the paper fibers, making it difficult to remove. On the other hand, the pearl pigment, which could not be removed, was conspicuous in a medium having a low lightness in which the luster pigment was visible.
One aspect of the present invention is an ink containing a resin-coated flaky metal pigment and a luster pigment composed of a pigment obtained by coating a transparent substrate with a metal oxide, and a thermochromic pigment. , It is possible to form a thermochromic handwriting that exhibits excellent luster even on a medium with high brightness such as white paper, and when the paper touches the handwriting, the paper surface that touches the handwriting is a resin-coated thin piece. To provide a water-based ink composition for a reversible thermochromic writing instrument, capable of suppressing the transfer of a metallic pigment, and excellent in removability of a luster pigment when the handwriting is thermally discolored by rubbing with a friction member or the like. With the goal.

A reversible thermochromic water-based ink composition is a reversible thermochromic composition containing an electron-donating color-developing organic compound, an electron-accepting compound, and a reaction medium that determines the temperature at which the color reaction of the two occurs. A color-changing microcapsule pigment, a resin-coated flaky metal pigment, a transparent base material coated with a metal oxide pigment, water, a thickener, and a resin, wherein the resin It is required that the glass transition temperature (Tg value) of is 0° C. or less.

The ink composition may contain a styrene-butadiene resin and/or an ethylene-vinyl acetate resin as a resin, and the content of the resin may be 1 to 15% by mass based on the total mass of the ink composition. May be a requirement.

A writing instrument is required to contain the ink composition. The writing instrument may be provided with a friction member, and the writing instrument may be a ballpoint pen.

One aspect of the present invention is an ink containing a resin-coated flaky metal pigment and a luster pigment composed of a pigment obtained by coating a transparent substrate with a metal oxide, and a thermochromic pigment. , It is possible to form a thermochromic handwriting that exhibits excellent luster even on a medium with high brightness such as white, and when the paper touches the handwriting, the paper surface that touches the handwriting is a resin-coated thin piece. A water-based ink composition for writing instruments and a writing instrument incorporating it, which can suppress the transfer of metallic pigments and is excellent in removability of bright pigments when handwriting is thermally discolored by rubbing with a friction member or the like. can provide.

FIG. 2 is an explanatory diagram showing color change behavior of a microcapsule pigment encapsulating a reversible thermochromic composition. FIG. 2 is an explanatory diagram showing color change behavior of a microcapsule pigment encapsulating a reversible thermochromic composition having color memory.

In the present specification, the content of each component in the composition refers to the total amount of the multiple substances present in the composition when there are multiple substances corresponding to each component in the composition, unless otherwise specified. means. Hereinafter, embodiments of the present invention will be described in detail. However, the embodiments shown below are examples of ink compositions and the like for embodying the technical idea of the present invention, and the present invention is not limited to the ink compositions and the like shown below.

A reversible thermochromic water-based ink composition (hereinafter also simply referred to as "ink composition") comprises an electron-donating color-forming organic compound, an electron-accepting compound, and a reaction medium that determines the temperature at which the color reaction occurs between the two. It contains a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition, a luster pigment, water, a thickener, and a resin having a glass transition temperature of 0° C. or less.

(Luminous pigment)
As the luster pigment, a resin-coated flaky metal pigment capable of expressing excellent luster by reflecting light in the state of handwriting and a pigment obtained by coating a transparent base material with a metal oxide are applied. be. When the two types of pigments described above are used together as the luster pigment, the luster of the handwriting can be improved, and the handwriting can be formed with excellent luster even on a medium with high brightness such as white paper.

A resin-coated flaky metal pigment (hereinafter sometimes referred to as a first bright pigment) is formed by providing a resin layer on a metal foil. The resin layers are formed on both sides of the metal foil, for example. Moreover, the resin layer may contain a coloring agent. Aluminum, for example, may be used as the metal, and its surface may be mirror-finished. The average thickness of the first bright pigment is, for example, 0.5 μm or more and 5 μm or less, preferably 1 μm or more and 3 μm or less. The average particle size of the first bright pigment is, for example, 5 μm or more and 200 μm or less, preferably 10 μm or more and 60 μm or less. is more effectively suppressed from settling and aggregating to separate from the solvent, making it possible to form good handwriting with more suppressed unevenness in color and luster. In addition, the removability of the first bright pigment is improved when handwriting is rubbed.

Here, the average thickness and average particle diameter of the first bright pigment are the arithmetic of the maximum thickness of each particle measured by image analysis of the observed image with a digital microscope in accordance with JIS Z 8827-1: 2008. It is the arithmetic mean value of the average value and the maximum particle size. For the image analysis, for example, image analysis type particle size distribution measurement software "Mac-View" manufactured by Mountec can be used.

The aspect ratio, which is the ratio of the average particle diameter to the average thickness of the first bright pigment, is, for example, 2 or more and 50 or less, preferably 10 or more and 30 or less. When the aspect ratio is within the above range, a handwriting having more excellent luster can be formed. The true specific gravity of the first bright pigment is, for example, about 1.2 or more and 1.3 or less, and is excellent in dispersibility. A resin-coated flaky metal pigment can be obtained, for example, by vacuum-depositing aluminum or the like on one side of a resin film made of polyester or the like, coating the film with a desired color, and then finely cutting the film.

The first bright pigment is also called lame pigment, and specific examples thereof include Elgie neo SILVER #35, Elgie neo R-GOLD #35, Elgie neo B-GOLD #35, Elgie neo S-GOLD #35, and Elgie neo. SILVER #100, Elgie neo R-GOLD #100, Elgie neo B-GOLD #100, Elgie neo S-GOLD #100, Elgie neo RED #100, Elgie neo BLUE #100, Elgie neo GREEN #100, Elgie neo VIOLET # 100, Elgie neo BLACK #100, Elgie neo COPPER #100, Elgie neo PINK #100, Elgie neo YELLOW #100, Elgie neo R-GOLD #150, Elgie neo B-GOLD #150, Elgie neo S-GOLD #150, Elgie neo RED #150, Elgie neo BLUE #150, Elgie neo GREEN #150, Elgie neo VIOLET #150, Elgie neo BLACK #150, Elgie neo COPPER #150, Elgie neo PINK #150, Elgie neo YELLOW #150, Elgie neo SILVER #200, Elgie neo R-GOLD #200, Elgie neo B-GOLD #200, Elgie neo S-GOLD #200, Elgie neo RED #200, Elgie neo BLUE #200, Elgie neo GREEN #200, Elgie neo VIOLET # 200, Elgie neo BLACK #200, Elgie neo COPPER #200, Elgie neo PINK #200, Elgie neo YELLOW #200, Elgie neo SILVER #325, Elgie neo R-GOLD #325, Elgie neo B-GOLD #325, Elgie neo S-GOLD #325, Elgie neo RED #325, Elgie n
eo BLUE #325, Elgie neo GREEN #325, Elgie neoVIOLET #325, Elgie neo BLACK #325, Elgie neo COPPER #325, Elgie neo PINK #325, Elgie neo YELLOW #325, Elgie neo SILVER #500, Elgie neo R- GOLD #500, Elgie neo B-GOLD #500, Elgie neo S-GOLD #500 (manufactured by Oike Imaging Co., Ltd.), diamond piece LGGold No. 55, diamond piece DG Gold No. 55, Diamond Peace Green No. 55, Diamond Piece Blue No. 55, Diamond Piece Red No. 55, diamond piece Maroon No. 55, Diamond Peace Ocean Green No. 55, Diamond Piece Sky Blue No. 55, Diamond Piece Black No. 55, Diamond Piece Pink No. 55, diamond piece Violet No. 55, diamond piece Emerald No. 55, diamond piece Copper No. 55, Diamond Piece LG Gold H25, Diamond Piece DG Gold H25, Diamond Piece Green H25, Diamond Piece Blue H25, Diamond Piece Red H25, Diamond Piece Maroon H25, Diamond Piece Ocean Green H25, Diamond Piece Sky Blue H25, Diamond Piece Black H25 , Diamond Piece Pink H25, Diamond Piece Violet H25, Diamond Piece Emerald H25, Diamond Piece Copper H25, Diamond Piece LG Gold H55, Diamond Piece DG Gold H55, Diamond Piece Green H55, Diamond Piece Blue
H55, Diamond Piece Red H55, Diamond Piece Maroon H55, Diamond Piece Ocean Green H55, Diamond Piece Sky Blue H55, Diamond Piece Black H55, Diamond Piece Pink H55, Diamond Piece Violet H55, Diamond Piece Emerald H55, Diamond Piece Copper H55, Diamond Piece LG Gold CO-40UC, Diamond Piece DG Gold CO-40UC, Diamond Piece Green CO-40UC, Diamond Piece Blue CO-40UC, Diamond Piece Red CO-40UC, Diamond Piece Pink CO-40UC, Diamond Piece Lavender CO-40UC ( (manufactured by Dia Kogyo Co., Ltd.) and the like. The first bright pigment may be used alone or in combination of two or more.

The content of the first bright pigment is preferably 0.1 to 20% by mass, more preferably 0.05 to 15% by mass, based on the total mass of the ink composition. Particularly preferably, it is 0.1 to 10% by mass. If the content is within the above range, the chemical stability in the ink and the heat discoloration with excellent brightness and suppressed color unevenness can be achieved by suppressing aggregation and sedimentation of the bright pigment in the ink. Easy to form sexual handwriting. Further, when the handwriting is rubbed with a friction member or the like, the first bright pigment on the handwriting can be easily removed.

Various substances can be applied to the base material and the metal oxide for the pigment (hereinafter sometimes referred to as the second bright pigment) obtained by coating a transparent base material with a metal oxide. Specific examples of transparent substrates include natural mica, synthetic mica such as KMg3(AlSi3O10)F2, flat glass, silica flakes, and flaky aluminum oxide. Examples of the metal oxide that coats the substrate include oxides of titanium, zirconium, chromium, vanadium, iron, etc. Metal oxides containing titanium oxide as a main component are preferred. The second bright pigment presents a metallic luster of gold, silver or metallic color depending on the coverage of the metal oxide covering the surface of the substrate. The second bright pigment may be a metal oxide layer such as titanium oxide coated with iron oxide or a non-thermochromic dye/pigment.

Examples of the shape of the second bright pigment include a flat shape and a scale shape. The second bright pigment has an average thickness of, for example, 0.1 μm or more and 5 μm or less, and an average particle diameter of, for example, 0.2 μm or more and 200 μm or less, preferably 2 μm or more and 100 μm or less. When the average particle size of the second bright pigment is within the above range, sedimentation and aggregation of the bright pigment and separation from the solvent are more effectively suppressed, and unevenness in color and brightness is further suppressed. It becomes possible to form good handwriting. In addition, the removability of the bright pigment is improved when handwriting is rubbed.

The second bright pigment is also called a pearl pigment, and specific examples thereof include the following. As pigments in which the surface of natural mica is coated with a metal oxide such as titanium oxide, trade name "Iriodin" manufactured by Merck Co., Ltd. Product numbers: 100 (particle size distribution 10 μm to 60 μm: silver pearl), 103 (particle size distribution 10 μm to 60 μm), 120 (particle size distribution 5 μm to 25 μm: luster satin), 123 (particle size distribution 5 μm to 25 μm), 201 (particle size distribution 5 μm to 25 μm: rutile fine gold), 205 (particle size distribution 10 μm to 60 μm: rutile platinum gold), 221 (particle size Distribution 5 μm to 25 μm: rutile fine blue), 225 (particle size distribution 10 μm to 60 μm: rutile blue pearl), 231 (particle size distribution 5 μm to 25 μm: rutile fine red), 235 (particle size distribution 10 μm to 60 μm: rutile green pearl), Engel Product name “Lumina Colors” manufactured by Hard Co., Ltd. Product number: Lumina Gold (particle size distribution 10 μm to 48 μm: gold), Lumina Red (particle size distribution 10 μm to 48 μm: metallic red), Lumina Red Blue (particle size distribution 10 μm to 48 μm: metallic blue) , Lumina Aqua Blue (particle size distribution 10 μm to 48 μm: metallic blue), Lumina Green (particle size distribution 10 μm to 48 μm: metallic green), Lumina Turquoise (particle size distribution 10 μm to 48 μm: metallic green).

As a pigment in which the surface of synthetic mica is coated with a metal oxide, Nihon Koken Kogyo Co., Ltd. trade name "Urutimica" Product number: SB-100 (particle size distribution 5 μm to 30 μm: silver), SD-100 (particle size distribution 10 μm to 60 μm: silver), SE-100 (particle size distribution from 15 μm to 100 μm: silver), SF-100 (particle size distribution from 44 μm to 150 μm: silver), SH-100 (particle size distribution from 150 μm to 600 μm: silver), YB-100 (particle size Distribution 5 μm to 30 μm: gold), YD-100 (particle size distribution 10 μm to 60 μm: gold), YE-100 (particle size distribution 15 μm to 100 μm: gold), YF-100 (particle size distribution 44 μm to 150 μm: gold), RB-100 (particle size distribution 5 μm to 300 μm: metallic red), RD-100 (particle size distribution 10 μm to 60 μm: metallic red), RE-100 (particle size distribution 15 μm to 100 μm: metallic red), RF-100 (particle size distribution 44 μm to 150 μm: metallic red), RBB-100 (particle size distribution 5 μm to 30 μm: metallic purple), RBD-100 (particle size distribution 10 μm to 60 μm: metallic purple), RBE-100 (particle size distribution 15 μm to 100 μm: metallic purple), RBF-100 (particle size distribution 44 μm to 150 μm: metallic purple), VB-100 (particle size distribution 5 μm to 30 μm: metallic violet), VD-100 (particle size distribution 10 μm to 60 μm: metallic violet), VE-100 (particle size distribution 15 μm to 100 μm: metallic violet) , VF-100 (particle size distribution from 44 μm to 150
μm: metallic violet), BB-100 (particle size distribution 5 μm to 30 μm: metallic blue), BD-100 (particle size distribution 10 μm to 60 μm: metallic blue), BE-100 (particle size distribution 15 μm to 100 μm: metallic blue), BF- 100 (particle size distribution 44 μm to 150 μm: metallic blue), GB-100 (particle size distribution 5 μm to 30 μm: metallic green), GD-100 (particle size distribution 10 μm to 60 μm: metallic green), GE-100 (particle size distribution 15 μm to 100 μm: metallic green) , GF-100 (particle size distribution: 44 μm to 150 μm: metallic green).

As a pigment obtained by coating the surface of a flat glass piece with a metal oxide, scaly glass pieces coated with titanium oxide (product name: Metashine) MC5090RS (average particle size: 90 μm: silver), MC5090RY manufactured by Nippon Sheet Glass Co., Ltd. (average particle size 90 μm: gold), MC5090RR (average particle size 90 μm: red), MC5090RV (average particle size 90 μm: purple), MC5090RB (average particle size 90 μm: blue), MC5090RG (average particle size 90 μm: green), MC1080RS (average particle size 80 μm: silver), MC1080RY (average particle size 80 μm: gold), MC1080RR (average particle size 80 μm: red), MC1080RB (average particle size 80 μm: blue), MC1080RG (average particle size 80 μm: green), MC1040RS (average particle size 40 μm: silver), MC1040RY (average particle size 40 μm: gold), MC1040RR (average particle size 40 μm: red), MC1040RB (average particle size 40 μm: blue), MC1040RG (average particle size 40 μm: green), MC1020RS (average particle size 20 μm: silver), MC1020RY (average particle size 20 μm: gold), MC1020RR (average particle size 20 μm: red), MC1020RB (average particle size 20 μm: blue), MC1020RG (average particle size 20 μm: green), MC1080RSS1 (average particle diameter 80 μm: silver), MC1080RYS1 (average particle diameter 80 μm: gold), and the like.

As a pigment in which the surface of silica flakes is coated with a metal oxide, the product name "Color Stream" manufactured by Merck Co., Ltd. Product number: F20-00WNT Autumn Mystery (particle size distribution 5 μm to 40 μm), T20-01WNT Viola Fantasy (particle size distribution 5 μm to 40 μm), etc. can be exemplified.

As pigments in which the surface of flaky aluminum oxide is coated with a metal oxide, trade name "Xiralic" manufactured by Merck Co., Ltd. Product number: T50-10 (particle size distribution 10 μm to 30 μm: silver), T60-10WNT (particle size distribution 10 μm to 30 μm: silver), T60-20WNT (particle size distribution 10 μm to 30 μm: gold), T60-24WNT (particle size distribution 10 μm to 30 μm: metallic green), T60-23WNT (particle size distribution 10 μm to 30 μm: metallic blue). The second bright pigment may be used singly or in combination of two or more.

The content of the second bright pigment is preferably 0.01 to 20% by mass, more preferably 0.05 to 15% by mass, relative to the total mass of the ink composition. Particularly preferably, it is 0.1 to 10% by mass. If the content is within the above range, the chemical stability in the ink and the heat discoloration with excellent brightness and suppressed color unevenness can be achieved by suppressing aggregation and sedimentation of the bright pigment in the ink. Easy to form sexual handwriting. In addition, it is easy to remove the second bright pigment when handwriting is rubbed with a friction member or the like.

Further, the total content of the first bright pigment and the second bright pigment is preferably 0.02 to 20% by mass, more preferably 0.05 to 15% by mass, based on the total mass of the ink composition. is more preferred. Particularly preferably, it is 0.1 to 10% by mass. When the content is within the above range, the brightness of the handwriting, the removability of the bright pigment when the handwriting is rubbed, and the visibility of thermal discoloration of the handwriting are well balanced.

The content ratio of the second bright pigment to the first bright pigment in the ink composition (second bright pigment/first bright pigment) is, for example, 0.05 to 100, preferably 0.1 to 20, more preferably 0.2-5. When the content ratio is within the above range, the brightness of the handwriting, the removability of the bright pigment when the handwriting is rubbed with a friction member or the like, and the visibility of heat discoloration of the handwriting tend to be well balanced.

Furthermore, as the luster pigment, metal coated glass flakes, metal powder pigments, cholesteric liquid crystal type metallic luster pigments, etc. can be applied together with the first luster pigment and the second luster pigment.

As metal-coated glass flakes, glass flakes whose surfaces are coated with gold or silver can be applied. Specific examples of the metal-coated glass flakes include Nippon Sheet Glass Co., Ltd. trade name "Metashine" 2020PS (average particle diameter 25 μm: silver), 2040PS (average particle diameter 40 μm: silver), 1030GP (average particle diameter 30 μm: gold), etc. can be exemplified. The metal-coated glass flakes may be used singly or in combination of two or more.

As the metal powder pigment, aluminum, brass, stainless steel, tin, zinc, bronze, nickel, copper, gold, silver, etc. can be applied, and aluminum is preferably used since it has a low specific gravity and does not easily settle in ink. The metal powder pigments may be used singly or in combination of two or more.

Specific examples of cholesteric liquid crystal type metallic luster pigments include Wacker Chemie's product name "Helicone HC", product numbers: Sapphire (SLM90020), Scarabeus (SLM90120), Jade (SLM90220), Maple (SLM90320), and the like. The cholesteric liquid crystal type metallic luster pigment has an average thickness of, for example, 3 μm to 15 μm, preferably 5 μm to 10 μm, and an average particle size of 1 μm to 100 μm. The cholesteric liquid crystal type metallic luster pigment may be used singly or in combination of two or more.

The ink composition contains at least one reversible thermochromic microcapsule pigment. Reversible thermochromic microcapsule pigments (hereinafter also simply referred to as "microcapsule pigments") are composed of an electron-donating color-forming organic compound, an electron-accepting compound, and a reaction medium that determines the temperature at which the color reaction of the two occurs. It contains a thermochromic composition.

As the microcapsule pigment, it is described in JP-B-51-44706, JP-B-51-44707, JP-B-1-29398, etc., which changes color before and after a predetermined temperature (discoloration point). However, it exhibits a decoloring state in a temperature range above the high-temperature side discoloration point, and a colored state in a temperature range below the low-temperature side discoloration point. The state is maintained as long as the heat or cold required to develop the state is applied, but returns to the state exhibited at room temperature when the heat or cold is no longer applied, and the hysteresis width is relatively small. A microcapsule pigment encapsulating a heat-erasable reversible thermochromic composition having properties (ΔH=1° C. to 7° C.) can be used (see FIG. 1).

In addition, reversible thermochromic compositions exhibiting large hysteresis characteristics are described in JP-A-2006-137886, JP-A-2006-188660, JP-A-2008-45062, JP-A-2008-280523, etc. A microcapsule pigment encapsulating a substance can also be used. That is, the shape of the curve plotting the change in color density due to temperature change is greatly different when the temperature is increased from the lower temperature side than the discoloration temperature range and when the temperature is decreased from the higher temperature side than the discoloration temperature range. The color changes along the path, and the color development state in a low temperature range below the complete color development temperature (t1), or the color disappearance state in a high temperature range above the complete color development temperature (t4), is in a specific temperature range [between t2 and t3 temperature range (substantially two-phase retention temperature range)] can be used.

The hysteresis characteristics in the color density-temperature curve of microcapsule pigments encapsulating a reversible thermochromic composition having color memory will be described.
In FIG. 2, the vertical axis represents color density, and the horizontal axis represents temperature. Changes in color density due to temperature changes progress along the arrows. Here, A is a point indicating the density at a temperature t4 (hereinafter referred to as a complete decoloring temperature) at which a completely decolored state is reached, and B is a temperature t3 at which decoloring starts (hereinafter referred to as a decoloring start temperature). C is the point indicating the concentration at the temperature t2 at which color development starts (hereinafter referred to as the color development start temperature), and D is the temperature t1 at which the color is fully developed (hereinafter referred to as the complete color development temperature). ) is the point indicating the concentration in
The discoloration temperature range is the temperature range between t1 and t4, in which both the colored state and the decolored state can coexist, and the temperature range between t2 and t3, which is a region with a large difference in color density, is the substantial discoloration temperature range. is.
Further, the length of the line segment EF is a measure of the color change contrast, and the length of the line segment HG passing through the midpoint of the line segment EF is the temperature width (hereinafter referred to as hysteresis width ΔH) indicating the degree of hysteresis. If the ΔH value is small, only one of the states before and after discoloration can exist in the room temperature range. Also, when the ΔH value is large, it becomes easy to maintain each state before and after discoloration.

The complete decoloring temperature t4 is a temperature at which color is decolored by frictional heat or the like generated by friction between the friction member and the writing surface. More preferably, it is in the range of 60° C. or higher and 80° C. or lower, and the complete coloring temperature t1 can be a temperature that can only be obtained in a freezer room, a cold region, etc. For example, it is 0° C. or lower, preferably -50° C. above -5°C, more preferably between -50°C and -10°C.

The electron-donating color-forming organic compound, the electron-accepting compound and the reaction medium are described below.

(Electron-donating color-forming organic compound)
The electron-donating color-developing organic compound is a component that determines color, and develops color by donating electrons to an electron-accepting compound that is a color developer.

Examples of electron-donating color-developing organic compounds include phthalide compounds, fluoran compounds, stilinoquinoline compounds, diazarhodamine lactone compounds, pyridine compounds, quinazoline compounds, and bisquinazoline compounds, with phthalide compounds and fluoran compounds being preferred.

Examples of phthalide compounds include diphenylmethanephthalide compounds, phenylindolylphthalide compounds, indolylphthalide compounds, diphenylmethaneazaphthalide compounds, phenylindolylazaphthalide compounds, derivatives thereof, and the like. Azaphthalide compounds and derivatives thereof are preferred.
Further, examples of fluoran compounds include aminofluoran compounds, alkoxyfluoran compounds, and derivatives thereof.

Examples of such electron-donating color-forming organic compounds include:
3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide,
3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide,
3,3-bis(1-n-butyl-2-methylindol-3-yl)phthalide,
3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide,
3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-(2-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-[2-ethoxy-4-(N-ethylanilino)phenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-(2-acetamido-4-diethylaminophenyl)-3-(1-propylindol-3-yl)-4-azaphthalide,
3,6-bis(diphenylamino)fluorane,
3,6-dimethoxyfluorane,
3,6-di-n-butoxyfluorane,
2-methyl-6-(N-ethyl-Np-tolylamino)fluorane,
3-chloro-6-cyclohexylaminofluorane,
2-methyl-6-cyclohexylaminofluorane,
2-(2-chloroamino)-6-dibutylaminofluorane,
2-(2-chloroanilino)-6-di-n-butylaminofluorane,
2-(3-trifluoromethylanilino)-6-diethylaminofluorane,
2-(3-trifluoromethylanilino)-6-dipentylaminofluorane,
2-(dibenzylamino)-6-diethylaminofluorane,
2-(N-methylanilino)-6-(N-ethyl-Np-tolylamino)fluorane,
1,3-dimethyl-6-diethylaminofluorane,
2-chloro-3-methyl-6-diethylaminofluorane,
2-anilino-3-methyl-6-diethylaminofluorane,
2-anilino-3-methoxy-6-diethylaminofluorane,
2-anilino-3-methyl-6-di-n-butylaminofluorane,
2-anilino-3-methoxy-6-di-n-butylaminofluorane,
2-xylidino-3-methyl-6-diethylaminofluorane,
2-anilino-3-methyl-6-(N-ethyl-Np-tolylamino)fluorane,
1,2-benz-6-diethylaminofluorane,
1,2-benz-6-(N-ethyl-N-isobutylamino)fluorane,
1,2-benz-6-(N-ethyl-N-isoamylamino)fluorane,
2-(3-methoxy-4-dodecoxystyryl)quinoline,
Spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1′(3′H)isobenzofuran]-3′-one,2-(diethylamino)-8-(diethylamino)-4-methyl ,
Spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1′(3′H)isobenzofuran]-3′-one, 2-(di-n-butylamino)-8-(di -n-butylamino)-4-methyl,
Spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1′(3′H)isobenzofuran]-3′-one, 2-(di-n-butylamino)-8-(diethylamino )-4-methyl,
Spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1′(3′H)isobenzofuran]-3′-one, 2-(di-n-butylamino)-8-(N -ethyl-Ni-amylamino)-4-methyl,
Spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1′(3′H)isobenzofuran]-3′-one, 2-(dibutylamino)-8-(dipentylamino)-4 - methyl,
4,5,6,7-tetrachloro-3-[4-(dimethylamino)-2-methoxyphenyl]-3-(1-butyl-2-methyl-1H-indol-3-yl)-1(3H )—isobenzofuranone,
4,5,6,7-tetrachloro-3-[4-(diethylamino)-2-ethoxyphenyl]-3-(1-ethyl-2-methyl-1H-indol-3-yl)-1(3H) - isobenzofuranone,
4,5,6,7-tetrachloro-3-[4-(diethylamino)-2-ethoxyphenyl]-3-(1-pentyl-2-methyl-1H-indol-3-yl)-1(3H) - isobenzofuranone,
4,5,6,7-tetrachloro-3-[4-(diethylamino)-2-methylphenyl]-3-(1-ethyl-2-methyl-1H-indol-3-yl)-1(3H) - isobenzofuranone,
3′,6′-bis[phenyl(2-methylphenyl)amino]-spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one,
3′,6′-bis[phenyl(3-methylphenyl)amino]-spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one,
3′,6′-bis[phenyl(3-ethylphenyl)amino]-spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one,
2,6-bis(2′-ethyloxyphenyl)-4-(4′-dimethylaminophenyl)pyridine,
2,6-bis(2′,4′-diethyloxyphenyl)-4-(4′-dimethylaminophenyl)pyridine,
2-(4′-dimethylaminophenyl)-4-methoxy-quinazoline,
4,4'-(ethylenedioxy)-bis[2-(4-diethylaminophenyl)quinazoline] and the like.

As fluoranes, compounds having a substituent on the phenyl group that forms the xanthene ring, and compounds that have a substituent on the phenyl group that forms the xanthene ring and also have a substituent on the phenyl group that forms the lactone ring (e.g., methyl group, etc.) (halogen atom such as alkyl group, chloro group, etc.), and compounds exhibiting blue or black color.

(Electron-accepting compound)
The electron-accepting compound receives electrons from the electron-donating color-forming organic compound and functions as a developer thereof.

As electron-accepting compounds, for example, a group of compounds having an active proton, a group of pseudo-acidic compounds (although not acids, compounds that act as acids in reversible thermochromic compositions to develop electron-donating color-forming organic compounds) group), and compounds having electron vacancies, etc., and compounds selected from the group of compounds having active protons are preferred.

Examples of the compound group having an active proton include compounds having a phenolic hydroxyl group and derivatives thereof, carboxylic acids and derivatives thereof, aromatic carboxylic acids and derivatives thereof, aliphatic carboxylic acids having 2 to 5 carbon atoms and derivatives thereof, 2-hydroxycarboxylic acid derivatives, N-substituted amino acid derivatives, acidic phosphate esters and derivatives thereof, azole compounds and derivatives thereof, 1,2,3-triazole and derivatives thereof, cyclic carbosulfimides, Preferred are halohydrins having 2 to 5 carbon atoms, sulfonic acids and their derivatives, and inorganic acids.

Examples of pseudo-acidic compounds include metal salts of compounds having a phenolic hydroxyl group, metal salts of carboxylic acids, metal salts of acidic phosphoric acid esters, metal salts of sulfonic acids, aromatic carboxylic anhydrides, and aliphatic carboxylic acids. Examples include anhydrides, mixed acid anhydrides of aromatic carboxylic acids and sulfonic acids, cycloolefin dicarboxylic acid anhydrides, urea and its derivatives, thiourea and its derivatives, guanidine and its derivatives, and halogenated alcohols.

Examples of compounds having electron vacancies include borates, borate esters, and inorganic salts.

Among the electron-accepting compounds listed above, a compound having a phenolic hydroxyl group is preferred from the viewpoint of more effectively exhibiting thermochromic properties.

Compounds having a phenolic hydroxyl group include, for example, a wide range of compounds from monophenol compounds to polyphenol compounds, and further include bisphenol compounds, trisphenol compounds, etc., and phenol-aldehyde condensed resins. A compound having a phenolic hydroxyl group preferably has at least two benzene rings. In addition, the compound having a phenolic hydroxyl group may have substituents such as alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, carboxy groups and their esters, amide groups, and halogen groups.

Examples of metals contained in metal salts of compounds having phenolic hydroxyl groups include sodium, potassium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum. is mentioned.

As a compound having one phenolic hydroxyl group, for example,
phenol,
o-cresol,
m-cresol,
p-cresol,
4-ethylphenol,
4-n-propylphenol,
4-n-butylphenol,
2-tert-butylphenol,
3-tert-butylphenol,
4-tert-butylphenol,
4-n-pentylphenol,
4-tert-pentylphenol,
4-n-octylphenol,
4-tert-octylphenol,
4-n-nonylphenol,
4-n-dodecylphenol,
3-n-pentadecylphenol,
4-n-stearylphenol,
1-(4-hydroxyphenyl)decan-1-one,
4-chlorophenol,
4-bromophenol,
4-trifluoromethylphenol,
4-methylthiophenol,
4-nitrophenol,
2-phenylphenol,
4-phenylphenol,
2-benzylphenol,
2-benzyl-4-chlorophenol,
4-cumylphenol,
4-hydroxybenzophenone,
4,4′-dihydroxybenzophenone,
4-chloro-4'-hydroxybenzophenone,
4-fluoro-4'-hydroxybenzophenone,
4-cyclohexylphenol,
2-hydroxybenzyl alcohol,
3-hydroxybenzyl alcohol,
4-hydroxybenzyl alcohol,
4-(2-hydroxyethyl)phenol,
3-methoxyphenol,
4-ethoxyphenol,
4-n-propoxyphenol,
4-n-butoxyphenol,
4-n-heptyloxyphenol,
4-(2-methoxyethyl)phenol,
α-naphthol,
β-naphthol,
2,3-dimethylphenol,
2,4-dimethylphenol,
2,6-dimethylphenol,
2,6-di-tert-butylphenol,
2,4-dichlorophenol,
2,4-difluorophenol, thymol,
3-methyl-4-methylthiophenol,
2-tert-butyl-5-methylphenol,
2,6-bis(hydroxymethyl)-4-methylphenol,
2,3,5-trimethylphenol,
2,6-bis(hydroxymethyl)-4-tert-octylphenol,
6-hydroxy-1,3-benzoxathiol-2-one,
2,4-bis(phenylsulfonyl)phenol,
2,4-bis(phenylsulfonyl)-5-methylphenol,
2,4-bis(4-methylphenylsulfonyl)phenol,
2-phenylphenol,
4-phenylphenol,
2,6-diphenylphenol,
3-benzylbiphenyl-2-ol,
3,5-dibenzylbiphenyl-4-ol,
4-cyano-4'-hydroxybiphenyl,
1-hydroxybenzotriazole,
1-hydroxy-5-methylbenzotriazole,
1-hydroxy-5-chlorobenzotriazole,
1-hydroxy-5-methoxybenzotriazole,
1-hydroxy-4-benzoylaminobenzotriazole,
1-hydroxy-4,5,6,7-tetrachlorobenzotriazole,
1,4-hydroxybenzotriazole,
1-hydroxy-5-nitrobenzotriazole,
1-hydroxy-5-phenylbenzotriazole,
1-hydroxy-5-benzylbenzotriazole,
1-hydroxy-5-ethylbenzotriazole,
1-hydroxy-5-n-octylbenzotriazole,
1-hydroxy-5-n-butylbenzotriazole,
n-butyl 4-hydroxybenzoate,
n-octyl 4-hydroxybenzoate,
4-hydroxybenzoic acid 2-heptadecafluorooctylethane,
benzyl 4-hydroxybenzoate,
4-hydroxybenzoic acid benzyl ester,
o-methylbenzyl 4-hydroxybenzoate,
m-methylbenzyl 4-hydroxybenzoate,
p-methylbenzyl 4-hydroxybenzoate,
p-ethylbenzyl 4-hydroxybenzoate,
4-hydroxybenzoate-p-propylbenzyl,
4-hydroxybenzoate-p-tert-butylbenzyl,
phenylethyl 4-hydroxybenzoate,
4-hydroxybenzoate-o-methylphenylethyl,
4-hydroxybenzoate-m-methylphenylethyl,
p-methylphenylethyl 4-hydroxybenzoate,
p-ethylphenylethyl 4-hydroxybenzoate,
4-hydroxybenzoate-p-propylphenylethyl,
4-Hydroxybenzoic acid-p-tert-butylphenylethyl and the like.

As a compound having two phenolic hydroxyl groups, for example,
Resorcinol,
2-methylresorcin,
4-n-hexylresorcin,
4-n-octylresorcin,
4-tert-octylresorcin,
4-benzoylresorcin,
4-nitroresorcin,
β-methyl resorcinate,
β-benzyl resorcinate,
2-chloro-4-pentanoylresorcin,
6-chloro-4-pentanoylresorcin,
2-chloro-4-hexanoylresorcin,
6-chloro-4-hexanoylresorcin,
2-chloro-4-propanoylresorcin,
6-chloro-4-propanoylresorcin,
2,6-dichloro-4-propanoylresorcin,
6-fluoro-4-propanoylresorcin,
2-chloro-4-phenylacetylresorcinol,
4-phenylacetyl-6-chlororesorcin,
2-chloro-4-β-phenylpropanoylresorcin,
6-chloro-4-β-phenylpropanoylresorcin,
2-chloro-4-phenoxyacetylresorcin,
6-chloro-4-phenoxyacetylresorcin,
4-benzoyl-2-chlororesorcin,
6-chloro-4-m-methylbenzoylresorcin,
4-[1′,3′,4′,9′a-tetrahydro-6′-hydroxyspiro(cyclohexane-1,9′-[9H]-xanthene)-4′a-[2H]-yl]-1 , 3-benzenediol,
hydroquinone,
methyl hydroquinone,
trimethylhydroquinone, catechol,
4-tert-butyl catechol,
1,6-dihydroxynaphthalene,
2,7-dihydroxynaphthalene,
1,5-dihydroxynaphthalene,
2,6-dihydroxynaphthalene,
2,4-dihydroxybenzophenone,
2,4-dihydroxy-2′-methylbenzophenone,
2,4-dihydroxy-3′-methylbenzophenone,
2,4-dihydroxy-4′-methylbenzophenone,
2,4-dihydroxy-4′-ethylbenzophenone,
2,4-dihydroxy-4′-n-propylbenzophenone,
2,4-dihydroxy-4′-isopropylbenzophenone,
2,4-dihydroxy-4'-n-butylbenzophenone, 2,4-dihydroxy-4'-isobutylbenzophenone,
2,4-dihydroxy-4′-tert-butylbenzophenone,
2,4-dihydroxy-4′-n-pentylbenzophenone,
2,4-dihydroxy-4′-n-hexylbenzophenone,
2,4-dihydroxy-4′-n-heptylbenzophenone,
2,4-dihydroxy-4′-n-octylbenzophenone,
2,4-dihydroxy-4′-n-decylbenzophenone,
2,4-dihydroxy-2',3'-dimethylbenzophenone,
2,4-dihydroxy-2',4'-dimethylbenzophenone,
2,4-dihydroxy-2',5'-dimethylbenzophenone,
2,4-dihydroxy-2',6'-dimethylbenzophenone,
2,4-dihydroxy-3′,4′-dimethylbenzophenone,
2,4-dihydroxy-3′,5′-dimethylbenzophenone,
2,4-dihydroxy-2',4',6'-trimethylbenzophenone,
2,4-dihydroxy-2'-methoxybenzophenone,
2,4-dihydroxy-3′-methoxybenzophenone,
2,4-dihydroxy-4'-methoxybenzophenone,
2,4-dihydroxy-2'-ethoxybenzophenone,
2,4-dihydroxy-4'-ethoxybenzophenone,
2,4-dihydroxy-4′-n-propoxybenzophenone,
2,4-dihydroxy-4′-isopropoxybenzophenone,
2,4-dihydroxy-4'-n-butoxybenzophenone,
2,4-dihydroxy-4'-isobutoxybenzophenone,
2,4-dihydroxy-4′-n-pentyloxybenzophenone,
2,4-dihydroxy-4′-n-hexyloxybenzophenone,
2,4-dihydroxy-4′-n-heptyloxybenzophenone,
2,4-dihydroxy-4′-n-octyloxybenzophenone,
2,4-dihydroxy-4′-n-nonyloxybenzophenone,
2,4-dihydroxy-2',3'-dimethoxybenzophenone,
2,4-dihydroxy-2',4'-dimethoxybenzophenone,
2,4-dihydroxy-2',5'-dimethoxybenzophenone,
2,4-dihydroxy-2',6'-dimethoxybenzophenone,
2,4-dihydroxy-3′,4′-dimethoxybenzophenone,
2,4-dihydroxy-3′,5′-dimethoxybenzophenone,
2,4-dihydroxy-3′,4′-diethoxybenzophenone,
2,4-dihydroxy-2',3',4'-trimethoxybenzophenone,
2,4-dihydroxy-2',3',6'-trimethoxybenzophenone,
2,4-dihydroxy-3′,4′,5′-trimethoxybenzophenone,
2,4-dihydroxy-3',4',5'-triethoxybenzophenone and the like.

As a bisphenol compound, for example,
1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)propane,
1,1-bis(4-hydroxyphenyl)n-butane,
1,1-bis(4-hydroxyphenyl)n-pentane,
1,1-bis(4-hydroxyphenyl)n-hexane,
1,1-bis(4-hydroxyphenyl)n-heptane,
1,1-bis(4-hydroxyphenyl)n-octane,
1,1-bis(4-hydroxyphenyl)n-nonane,
1,1-bis(4-hydroxyphenyl)n-decane,
1,1-bis(4-hydroxy-3-methylphenyl)decane,
1,1-bis(4-hydroxyphenyl)n-dodecane,
1,1-bis(4-hydroxyphenyl)-2-methylpropane,
1,1-bis(4-hydroxyphenyl)-3-methylbutane,
1,1-bis(4-hydroxyphenyl)-3-methylpentane,
1,1-bis(4-hydroxyphenyl)-2,3-dimethylpentane,
1,1-bis(4-hydroxyphenyl)-2-ethylbutane,
1,1-bis(4-hydroxyphenyl)-2-ethylhexane,
1,1-bis(4-hydroxyphenyl)-3,7-dimethyloctane,
1,1-bis(4-hydroxyphenyl)cyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxy-3-methyl)cyclohexane,
diphenolic acid,
1-phenyl-1,1-bis(4-hydroxyphenyl)methane,
2,2-bis(4-hydroxyphenyl)propane,
2,2-bis(4-hydroxyphenyl)n-butane,
2,2-bis(4-hydroxyphenyl)n-pentane,
2,2-bis(4-hydroxyphenyl)n-hexane,
2,2-bis(4-hydroxyphenyl)n-heptane,
2,2-bis(4-hydroxyphenyl)n-octane,
2,2-bis(4-hydroxyphenyl)n-nonane,
2,2-bis(4-hydroxyphenyl)n-decane,
2,2-bis(4-hydroxyphenyl)n-dodecane,
2,2-bis(4-hydroxyphenyl)-6,10,14-trimethylpentadecane,
1-phenyl-1,1-bis(4-hydroxyphenyl)ethane,
2,2-bis(4-hydroxyphenyl)methylpropionate,
2,2-bis(4-hydroxyphenyl)butyl propionate,
2,2-bis(4-hydroxy-3-methylphenyl)methylpropionate,
2,2-bis(4-hydroxyphenyl)ethyl propionate,
2,2-bis(4-hydroxyphenyl)-4-methylpentane,
2,2-bis(4-hydroxyphenyl)-4-methylhexane,
2,2-bis(4-hydroxyphenyl)hexafluoropropane,
2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)hexafluoropropane,
2,2-bis(4-hydroxy-3-methylphenyl)propane,
2,2-bis(4-hydroxy-3-methylphenyl)butane,
2,2-bis(4-hydroxy-3-isopropylphenyl)propane,
2,2-bis(3-sec-butylphenyl-4-hydroxy)propane,
2,2-bis(4-hydroxy-3-phenylphenyl)propane,
2,2-bis(3-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(3-fluoro-4-hydroxyphenyl)propane,
2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)propane,
9,9-bis(4-hydroxy-3-methylphenyl)fluorene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
3,3-bis(4-hydroxyphenyl)oxindole,
3,3-bis(4-hydroxy-3-methylphenyl)oxindole,
bis(2-hydroxyphenyl)methane,
bis(2-hydroxy-5-methylphenyl)methane,
bis(2-hydroxy-3-hydroxymethyl-5-methyl)methane,
4,4′-[1,4-phenylenebis(1-methylethylidene)]bis(2-methylphenol),
1,1-bis(4-hydroxy-3-phenylphenyl)cyclohexane,
3,3-ethyleneoxydiphenol,
1,4-bis(4-hydroxybenzoate)-3-methylbenzene,
4,4″-dihydroxy-3″-methyl-p-terphenyl,
4,4″-dihydroxy-3″-isopropyl-p-terphenyl,
2,2-dimethyl-1,3-bis(4-hydroxybenzoyloxy)propane,
2,2′-biphenol,
4,4′″-dihydroxy-p-quaterphenyl,
4,4-dihydroxydiphenyl ether, bis(4-hydroxyphenylthioethyl) ether,
bis(4-hydroxyphenyl)sulfone,
4-benzyloxy-4'-hydroxydiphenylsulfone,
4-(4-methylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-ethylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-n-propylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-isopropylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-n-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-isobutylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-sec-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-tert-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-methylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-ethylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-n-propylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-isopropylbenzyloxy)-4'-dihydroxyphenylsulfone,
4-(3-n-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-isobutylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-sec-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-tert-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-methylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-ethylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-n-propylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-isopropylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-n-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-isobutylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-sec-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-tert-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
2,4′-dihydroxydiphenyl sulfone,
3,4′-dihydroxydiphenyl sulfone,
4-hydroxydiphenyl sulfone,
4-methyl-4'-hydroxyphenylsulfone,
4-ethyl-4'-hydroxydiphenylsulfone,
4-n-propyl-4'-hydroxydiphenylsulfone,
4-isopropyl-4'-hydroxydiphenylsulfone,
4-chloro-4'-hydroxydiphenylsulfone,
4-fluoro-4'-hydroxydiphenylsulfone,
4-chloro-2-methyl-4'-hydroxydiphenylsulfone,
4-methoxy-4'-hydroxydiphenylsulfone,
4-ethoxy-4'-hydroxydiphenylsulfone,
4-n-propoxy-4'-hydroxydiphenylsulfone,
4-isopropoxy-4'-hydroxydiphenylsulfone,
4-n-butoxy-4'-hydroxydiphenylsulfone,
4-isobutoxy-4'-hydroxydiphenylsulfone,
4-sec-butoxy-4'-hydroxydiphenylsulfone,
4-tert-butoxy-4′-hydroxydiphenylsulfone,
4-n-pentyloxy-4'-hydroxydiphenylsulfone,
4-isopentyloxy-4'-hydroxydiphenylsulfone,
4-(1-propenyloxy)-4'-hydroxydiphenylsulfone,
4-(2-propenyloxy)-4'-hydroxydiphenylsulfone,
4-benzyloxy-4'-hydroxydiphenylsulfone,
4-(β-phenoxyethoxy)-4′-hydroxydiphenylsulfone,
4-(β-phenoxypropoxyl)-4′-hydroxydiphenylsulfone,
bis(2-allyl-4-hydroxydiphenyl)sulfone,
bis[4-hydroxy-3-(2-propenyl)phenyl]sulfone,
bis(3,5-dibromo-4-hydroxyphenyl)sulfone,
bis(3,5-dichloro-4-hydroxyphenyl)sulfone,
bis(3-phenyl-4-hydroxyphenyl)sulfone,
bis(4-hydroxy-3-n-propylphenyl)sulfone,
bis(4-hydroxy-3-methylphenyl)sulfone,
3,4-dihydroxydiphenyl sulfone,
3′,4′-dihydroxy-4-methyldiphenylsulfone,
3,4,4′-trihydroxydiphenyl sulfone,
bis(3,4-dihydroxyphenyl)sulfone,
2,3,4-trihydroxydiphenyl sulfone,
4-isopropoxy-4'-hydroxydiphenylsulfone,
4-n-propoxy-4'-hydroxydiphenylsulfone,
4-allyloxy-4'-hydroxydiphenylsulfone,
4-benzyloxy-4'-hydroxydiphenylsulfone,
4-(2-propenyloxy)-4'-hydroxydiphenylsulfone,
3-benzyl-4-benzyloxy-4'-hydroxydiphenylsulfone,
3-phenethyl-4-phenethyloxy-4'-hydroxydiphenylsulfone,
3-methylbenzyl-4-methylbenzyloxy-4'-hydroxydiphenylsulfone,
4-benzyloxy-3′-benzyl-4′-hydroxydiphenylsulfone,
4-phenethyloxy-3′-phenethyl-4′-hydroxydiphenylsulfone,
4-methylbenzyloxy-3'-methylbenzyl-4'-hydroxydiphenylsulfone,
α,α'-bis{4-(p-hydroxyphenylsulfone)phenoxy}-p-xylene,
4,4′-{oxybis(ethylene oxide-p-phenylenesulfonyl)}diphenol bis(4-hydroxyphenyl)sulfide,
bis(4-hydroxy-3-methylphenyl)sulfide,
bis(3,5-dimethyl-4-hydroxyphenyl)sulfide,
bis(3-ethyl-4-hydroxyphenyl) sulfide,
bis(3,5-diethyl-4-hydroxyphenyl)sulfide,
bis(4-hydroxy-3-n-propylphenyl)sulfide,
bis(3,5-di-n-propyl-4-hydroxyphenyl)sulfide,
bis(3-tert-butyl-4-hydroxyphenyl)sulfide,
bis(3,5-di-tert-butyl-4-hydroxyphenyl)sulfide,
bis(4-hydroxy-3-n-pentylphenyl)sulfide,
bis(3-n-hexyl-4-hydroxyphenyl)sulfide,
bis(3-n-heptyl-4-hydroxyphenyl)sulfide,
bis(5-tert-octyl-2-hydroxyphenyl)sulfide,
bis(2-hydroxy-3-tert-octylphenyl)sulfide,
bis(2-hydroxy-5-n-octyl-phenyl)sulfide,
bis(5-chloro-2-hydroxyphenyl) sulfide,
bis(3-cyclohexyl-4-hydroxyphenyl)sulfide,
bis(4-hydroxyphenylthioethoxy)methane,
1,5-(4-hydroxyphenylthio)-3-oxypentane,
1,8-bis(4-hydroxyphenylthio)-3,6-dioxaoctane and the like.

Examples of compounds having three phenolic hydroxyl groups include pyrogallol, phloroglucinol, phloroglucinol carboxylic acid, gallic acid, octyl gallate, and dodecyl gallate.

As a trisphenol compound, for example,
4,4′,4″-methylidyne trisphenol,
4,4′,4″-methylidynetris(2-methylphenol),
4,4′-[(2-hydroxyphenyl)methylene]bis(2,3,5-trimethylphenol),
4,4′-[(4-hydroxyphenyl)methylene]bis(2-methylphenol),
4,4′-[(4-hydroxyphenyl)methylene]bis(2,6-dimethylphenol),
4,4′-[(4-hydroxy-3-methoxyphenyl)methylene]bisphenol,
4,4′-[(4-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
4,4′,4″-ethylidine trisphenol,
4,4′,4″-ethylidine tris(2-methylphenol),
4,4′-[(2-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenol,
2,4-bis[(2-hydroxy-5-methylphenyl)methyl]-6-cyclohexylphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}methylidene]bisphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}propylidene]bisphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}butylidene]bisphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}pentylidene]bisphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}hexylidene]bisphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}heptylidene]bisphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}isobutylidene]bisphenol,
4,4′-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}neopentylidene]bisphenol,
2,2′-[1-{4-[1-(2-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol,
3,3′-[1-{4-[1-(3-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol,
4,4′-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-fluorophenol),
4,4′-[1-{4-[1-(3-chloro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-chlorophenol),
4,4′-[1-{4-[1-(3-bromo-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-bromophenol),
4,4′-[1-{4-[1-(4-hydroxy-3-methylphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-methylphenol),
4,4′-[1-{4-[1-(3-ethyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-ethylphenol),
4,4′-[1-{4-[1-(3-tert-butyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-tert-butylphenol),
4,4′-[1-{4-[1-(4-hydroxy-3-trifluoromethylphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-trifluoromethylphenol),
1,1-bis(4-hydroxyphenyl)-4-(4-hydroxy-α-ethyl)benzylcyclohexane,
4,4′-[(3-ethoxy-4-hydroxysiphenyl)methylene]bisphenol,
4,4′-[(3-hydroxyphenyl)methylene]bis(2,6-dimethylphenol),
2,2′-[(4-hydroxyphenyl)methylene]bis(3,5-dimethylphenol),
4,4′-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2,6-dimethylphenol),
2,2′-[(2-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
4,4′-[(3-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol),
4,4′-[(4-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol),
4,4′-[(3-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
4,4′-[(4-hydroxyphenyl-3-methoxy)methylene]bis(2-cyclohexyl-5-methylphenol),
1,1-bis(4-hydroxylphenyl)-4-hydroxyphenylcyclohexane,
4,4′-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-phenyl)propylidene]bis(2-cyclohexyl-5-methylphenol),
4,4′-[(2-hydroxyphenyl)methylene]bis(2-methylphenol),
2,4′,4″-methylidyne trisphenol,
4,4′-[(2-hydroxyphenyl)methylene]bis(3-methylphenol),
4,4′-[4-(4-hydroxyphenyl)-sec-butylidene]bis(4-hydroxyphenol),
2,2′-[(3-hydroxyphenyl)methylene]bis(3,5-dimethylphenol),
4,4′-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2,5-dimethylphenol),
4,4′-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2,6-dimethylphenol),
2,2′-[(2-hydroxy-3-methoxyphenyl)methylene]bis(3,5-dimethylphenol),
2,2′-[(3-hydroxy-4-methoxyphenyl)methylene]bis(3,5-dimethylphenol),
2,2′-[(4-hydroxy-3-methoxyphenyl)methylene]bis(3,5-dimethylphenol),
4,4′-[(2-hydroxyphenyl)methylene]bis(2-isopropylphenol),
4,4′-[(3-hydroxyphenyl)methylene]bis(2-isopropylphenol),
4,4′-[(4-hydroxyphenyl)methylene]bis(2-isopropylphenol),
2,2′-[(3-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
2,2′-[(4-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
2,2′-[(4-3-ethoxy-4-hydroxyphenyl)methylene]bis(3,5-dimethylphenol),
1,1-bis(4-hydroxy-3-methylphenyl)-4-(4-hydroxyphenyl)cyclohexane,
4,4′-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2-isopropylphenol),
4,4′-[(3-hydroxy-4-methoxyphenyl)methylene]bis(2-isopropylphenol),
4,4′-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2-isopropylphenol),
2,2′-[(2-hydroxy-3-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol,
2,2′-[(3-hydroxy-4-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol),
2,2′-[(4-hydroxy-3-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol),
4,4′-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-isopropylphenol),
2,2′-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
4,4′-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol),
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)cyclohexane,
4,4′-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2-tert-butyl-5-methylphenol),
4,4′-[(2-hydroxyphenyl)methylene]bis(2-cyclohexylphenol),
4,4′-[(3-hydroxyphenyl)methylene]bis(2-cyclohexylphenol),
4,4′-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-tert-butyl-6-methylphenol),
4,4′-[(3-methoxy-2-hydroxyphenyl)methylene]bis(2-cyclohexylphenol),
4,4′-[(3-hydroxy-4-methoxyphenyl)methylene]bis(2-cyclohexylphenol),
4,4′-[1-{4-[1-(3-fluoro-4-hydroxylophenyl)-1-methylethyl]phenyl}ethylidene]bis(2-tert-butylphenol),
4,4′-[1-{4-[1-(3,5-dimethyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2,6-dimethylphenol),
4,4′-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
4,4′-[(3-cyclohexyl-4-hydroxyphenyl)ethylidene]bis(2-cyclohexylphenol),
4,4′-[(5-cyclohexyl-4-hydroxy-2-methoxyphenyl)ethylidene]bis(2-cyclohexyl-5-methylphenol),
4,4′-[1-{4-[1-(3-cyclohexyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-cyclohexylphenol),
4,4′-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol,
4,4′-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-methylphenol),
4,4′-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2,6-dimethylphenol),
2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-methylphenol,
2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-methylphenol,
2,6-bis[(4-hydroxyphenyl)methyl]-4-methylphenol,
2,6-bis[(4-hydroxyphenyl)methyl]-4-ethylphenol,
2,4-bis[(4-hydroxy-3-methylphenyl)methyl]-6-methylphenol,
2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-methylphenol,
2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-ethylphenol,
2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-ethylphenol,
2,6-bis[(3,5-dimethyl-2-hydroxyphenyl)methyl]-4-methylphenol,
2,6-bis[(2,4-dimethyl-6-hydroxyphenyl)methyl]-4-methylphenol,
2,4-bis[(4-hydroxyphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-3,4-dimethylphenol,
2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol,
2,6-bis[(4-hydroxy-2,3,6-trimethylphenyl)methyl]-4-methylphenol,
2,4-bis[(4-hydroxy-3-methylphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-cyclohexylphenol,
2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-cyclohexylphenol,
2,6-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-4-ethylphenol,
2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol,
4,4′,4″-methylidinetris(2,6-dimethylphenol),
α-(4-hydroxy-3-methylphenyl)-α,α'-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α′-(4-hydroxy-3-methylphenyl)-α,α-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α,α-bis(4-hydroxy-3-methylphenyl)-α'-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α,α'-bis(4-hydroxy-3-methylphenyl)-α-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
1,1-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)-1-methylpropyl]cyclohexane,
2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol,
1,1′-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1,1′-bis(4-hydroxy-3-methylphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1,1′-bis(3,5-dimethyl-4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1-(4-hydroxyphenyl)-1-[4,4-bis(4-hydroxyphenyl)cyclohexyl]-4-isopropylcyclohexane,
4,4′-[3-(2,5-dimethyl-4-hydroxyphenyl)butylene]bis(2,5-dimethylphenol),
1,3,5-tri(4-hydroxy-3-phenylphenyl)adamantane,
1,3,5-tri(3-cyclohexyl-4-hydroxyphenyl)adamantane,
2,4-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-cyclohexylphenol,
2,4-bis[(3-cyclohexyl-4-hydroxyphenyl)methyl]-6-methylphenol,
2,4-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-fluorophenol,
2,6-bis[(3-fluoro-4-hydroxyphenyl)methyl]-4-fluorophenol,
2,4-bis[(3-fluoro-4-hydroxyphenyl)methyl]-6-methylphenol,
4,4′-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-biphenylpropylidene]bis(5-cyclohexyl-2-methylphenol),
4,4′-[3-(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropylidene]bis(2,5-dimethylphenol),
2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-methylphenol,
1,1,2-tris(4-hydroxyphenyl)ethane,
1,1,3-tris(4-hydroxyphenyl)propane,
1,1,4-tris(4-hydroxyphenyl)butane,
1,2,2-tris(4-hydroxyphenyl)propane,
1,2,2-tris(4-hydroxyphenyl)butane,
1,2,2-tris(4-hydroxyphenyl)pentane,
1,2,2-tris(4-hydroxyphenyl)hexane,
1,2,2-tris(4-hydroxyphenyl)heptane,
1,2,2-tris(4-hydroxyphenyl)octane,
1,2,2-tris(4-hydroxyphenyl)-3-methylbutane 1,2,2-tris(4-hydroxyphenyl)-3,3-dimethylbutane,
1,2,2-tris(4-hydroxyphenyl)-4,4-dimethylpentane,
1,3,3-tris(4-hydroxyphenyl)butane,
1,3,3-tris(4-hydroxyphenyl)pentane,
1,3,3-tris(4-hydroxyphenyl)hexane,
1,3,3-tris(4-hydroxyphenyl)heptane,
1,3,3-tris(4-hydroxyphenyl)octane,
1,3,3-tris(4-hydroxyphenyl)nonane,
1,4,4-tris(4-hydroxyphenyl)pentane,
1,4,4-tris(4-hydroxyphenyl)hexane,
1,4,4-tris(4-hydroxyphenyl)heptane,
1,4,4-tris(4-hydroxyphenyl)octane,
1,4,4-tris(4-hydroxyphenyl)nonane,
1,4,4-tris(4-hydroxyphenyl)decane,
1,2,2-tris(2-hydroxyphenyl)propane,
1,1,2-tris(3-hydroxyphenyl)propane,
1-(4-hydroxyphenyl)-2,2-bis(2-hydroxyphenyl)propane,
1,2,2-tris(3-fluoro-4-hydroxyphenyl)propane,
1,2,2-tris(3-chloro-4-hydroxyphenyl)propane,
1,2,2-tris(3-bromo-4-hydroxyphenyl)propane,
2,2-bis(3-ethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(3-tert-butyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(2-hydroxy-3-biphenylyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(3-trifluoromethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2-(3-methyl-4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)propane,
1-(3-methyl-4-hydroxyphenyl)-2,2-bis(4-hydroxyphenyl)propane,
3-(3-methyl-4-hydroxyphenyl)-1,3-bis(4-hydroxyphenyl)butane,
1-(3-methyl-4-hydroxyphenyl)-3,3-bis(4-hydroxyphenyl)butane,
4-(3-methyl-4-hydroxyphenyl)-1,4-bis(4-hydroxyphenyl)pentane,
1-(3-methyl-4-hydroxyphenyl)-4,4-bis(4-hydroxyphenyl)pentane,
1,2-bis(3-methyl-4-hydroxyphenyl)-2-(4-hydroxyphenyl)propane,
3,3-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)butane,
1,3-bis(3-methyl-4-hydroxyphenyl)-3-(4-hydroxyphenyl)butane,
4,4-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)pentane,
1,4-bis(3-methyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)pentane,
1,1,2-tris(3-methyl-4-hydroxyphenyl)ethane,
1,2,2-tris(3-methyl-4-hydroxyphenyl)propane,
1,1,3-tris(3-methyl-4-hydroxyphenyl)propane,
1,3,3-tris(3-methyl-4-hydroxyphenyl)butane,
1,1,4-tris(3-methyl-4-hydroxyphenyl)butane,
1,4,4-tris(3-methyl-4-hydroxyphenyl)pentane,
4,4′-[4-(4-hydroxyphenyl)-sec-butylidene]bis(2-methylphenol)
etc.

As compounds having four or more phenolic hydroxyl groups, for example,
bis[2-hydroxy-3-(2-hydroxy-5-methylbenzyl)-5-methylphenyl]methane,
4,6-bis[(4-hydroxyphenyl)methyl)-1,3-benzenediol,
4,4′-[(3,4-dihydroxyphenyl)methylene]bis(2,6-dimethylphenol),
4,4′-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
4,4′-[(3,4-dihydroxyphenyl)methylene]bis(2-methylphenol),
4,4′-[(3,4-dihydroxyphenyl)methylene]bis(2,3,6-trimethylphenol),
1,1,2,2-tetrakis(4-hydroxyphenyl)ethane,
1,1,2,2-tetrakis(4-hydroxy-3-methylphenyl)ethane,
1,1,2,2-tetrakis(3,5-dimethyl-4-hydroxyphenyl)ethane,
1,1,4,4-tetrakis(3,5-dimethyl-4-hydroxyphenyl)benzene,
2,2′-bis[4,4-(4-hydroxy-3-methylphenyl)cyclohexyl]propane,
2,2′-[(3,4-dihydroxyphenyl)methylene]bis(3,5-dimethylphenol),
3,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl)catechol,
4,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl)-1,3-benzenediol,
2,2′-[(3,4-dihydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
4,4′-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexylphenol),
bis[3-(2-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(3-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxybenzyl)-3-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(3-hydroxy-2-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(4-hydroxy-3-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(3-hydroxy-4-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxy-3-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
α,α′,α″,α′″-tetrakis(4-hydroxyphenyl)benzene, bis[3-(3,6-dimethyl-2-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
[3-(3,6-dimethyl-2-hydroxybenzyl)-2-hydroxy-5-methylphenyl] [3-(2,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl] methane,
bis[3-(2,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(3,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxy-3,4,6-trimethylbenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[2-hydroxy-3-(4-hydroxy-2,3,5-trimethylbenzyl)-5-methylphenyl]methane,
4,4′,4″,4′″-tetrakis(4-hydroxyphenyl)-1,1′-bicyclohexyl,
2,2′-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane,
4,4′,4″,4′″-tetrakis(4-hydroxy-3-methylphenyl)-1,1′-bicyclohexyl,
bis[3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)-4-hydroxy-5-methylphenyl]methane,
4,4′,4″,4′″-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,1′-bicyclohexyl,
1,1-bis[3-(2-hydroxy-5-methylbenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[3-(3,5-dimethyl-4-hydroxybenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
4,6-bis[α-methyl-(4-hydroxyphenyl)benzyl-1,3-benzenediol,
2,2-bis[3-(4-hydroxy-3-methylbenzyl)-4-hydroxy-5-methylphenyl]propane,
2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)benzyl]-4-[α-methyl-(3,5-dimethyl-4-hydroxyphenyl)benzyl]phenol,
4,4′,4″,4′″-tetrakis(4-hydroxy-3-isopropylphenyl)-1,1′-bicyclohexyl,
4,4′-bis[(3,4-dihydroxyphenyl)methylene]bis(2-isopropylphenol)2,4,6-tris(4-hydroxybenzyl)-1,3-benzenediol,
4,6-bis(3,5-dimethyl-4-hydroxybenzyl)pyrogallol,
3,3′-[(2-hydroxyphenyl)methylene]bis(5-methylcatechol),
2,6-bis(2,4-dihydroxybenzyl)-4-ethylphenol,
2,4-bis(2,4-dihydroxybenzyl)-6-cyclohexylphenol,
2,6-bis(5-tert-butyl-2,3-dihydroxybenzyl)-4-methylphenol,
2,4,6-tris(3,5-dimethyl-4-hydroxybenzyl)resorcin,
2,4,6-tris(3,5-dimethyl-2-hydroxybenzyl)resorcin,
2,6-bis(2,4-dihydroxybenzyl)-3,4-dimethylphenol,
2,6-bis[3-(2-hydroxy-5-methylbenzyl)-2,5-dimethyl-4-hydroxybenzyl]-3,4-dimethylphenol,
4,6-bis(α-methyl-4-hydroxybenzyl)pyrogallol,
4,4′-[1-{4-[1-(3,5-bis(4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis( 4-hydroxybenzyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(4-hydroxy-3-methylbenzyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[ 2,6-bis(3,5-dimethyl-4-hydroxybenzyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,6-trimethylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene] bis[2,6-bis(4-hydroxy-2,3,6-trimethylbenzyl)phenol],
bis[5-(2,4-dihydroxybenzyl)-4-hydroxy-3-methylphenyl]methane, bis[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane,
bis[3-(2,4-dihydroxy-3-methylbenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane,
bis[5-(4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane,
1,1-bis[5-(4-hydroxybenzoyl)-2,3,4-trihydroxyphenyl]ethane,
3,3′,5,5′-tetrakis(4-hydroxybenzyl)-4,4′-dihydroxybiphenyl,
3,3′,5,5′-tetrakis(4-hydroxy-3-methylbenzyl)-4,4′-dihydroxybiphenyl,
3,3′,5,5′-tetrakis(2-hydroxy-5-methylbenzyl)-4,4′-dihydroxybiphenyl,
3,3′,5,5′-tetrakis(3,5-dimethyl-4-hydroxybenzyl)-4,4′-dihydroxybiphenyl,
bis[3-(α,α-bis(4-hydroxy-3-methylphenyl)methyl-4-hydroxyphenyl]methane,
bis[3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane,
4,4′,4″-ethylidinetris{[2-(2-hydroxy-5-methyl)benzyl]-6-methylphenol},
2,2-bis[3,5-bis(2-hydroxy-5-methylphenylmethyl)phenyl]propane, bis[3-(α,α-bis(2,5-dimethyl-4-hydroxyphenyl)methyl-4 - hydroxyphenyl]methane,
bis[5-(3,5-dimethyl-4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane,
bis[3-(2,3,4-trihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane,
1,1-bis[3-(2,3,4-trihydroxybenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,8,15,22-tetranonyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane,
4,4′-[1-{4-[1-(3,5-bis(4-hydroxy-2-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(4-hydroxy-2-methylbenzyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(2-hydroxy-5-methylbenzyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(3-ethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(3-ethyl-4-hydroxybenzyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(3,5-dimethyl-2-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[ 2,6-bis(3,5-dimethyl-2-hydroxyphenyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(4-hydroxy-3-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(4-hydroxy-3-isopropylphenyl)phenol],
bis[3-(α,α-bis(3,5-dimethyl-4-hydroxyphenyl)methyl-4-hydroxyphenyl]methane,
bis[3-(α,α-bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)methyl-4-hydroxyphenyl]methane,
4,4′-[4-hydroxy-3,5-bis(2-hydroxybenzyl)methylene]bis[2,6-bis(2-hydroxybenzyl)]phenol,
4,4′-[4-hydroxy-3,5-bis(4-hydroxybenzyl)methylene]bis[2,6-bis(4-hydroxybenzyl)]phenol,
4,4′,4″-ethylidinetris[2,6-bis(2-hydroxybenzyl)phenol],
4,4′,4″-ethylidinetris[2,6-bis(4-hydroxybenzyl)phenol],
2,2-bis[3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl]propane,
1,8,15,22-tetraethyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane,
α,α′,α″,α′″-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,4-dimethylbenzene,
4,4′-[1-{4-[1-(3,5-bis(2-hydroxy-5-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(2-hydroxy-5-isopropylphenyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,5-trimethylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene] bis[2,6-bis(4-hydroxy-2,3,5-trimethylphenyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(3-sec-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[ 2,6-bis(3-sec-butyl-4-hydroxyphenyl)phenol],
4,4′-[1-{4-[1-(3,5-bis(3-tert-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[ 2,6-bis(3-tert-butyl-4-hydroxyphenyl)phenol],
2,6-bis{[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxy]benzyl}-4-methylphenol,
1,1-bis[5-(2,4-dihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[5-(2,3,4-trihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane,
2,2-bis[4,4',4'',4'''-tetrakis(3,5-dihydroxymethyl-4-hydroxyphenyl)cyclohexyl]propane and the like.

Examples of carboxylic acids and derivatives thereof include
3,5-di(α-methylbenzyl)salicylic acid,
4-(2-p-methoxyphenyloxyethoxy)salicylic acid,
4-hydroxyphenylbenzoic acid,
p-chlorobenzoic acid,
4-[2-(p-methoxyphenoxy)ethyloxy]salicylic acid,
4-[3-(p-tolylsulfonyl)propyloxy]salicylic acid,
5-[p-(2-p-methoxyphenoxyethoxy)cumyl]salicylic acid,
4-octyloxycarbonylaminosalicylic acid,
3,5-distyrenated salicylic acid,
N-(p-toluenesulfonyl)-glycine,
N-(p-toluenesulfonyl)-alanine,
N-(p-toluenesulfonyl)-β-alanine,
N-phenylaminocarbonyl-glycine,
N-phenylaminocarbonyl-valine,
N-(m-tolylaminocarbonyl)-phenylalanine,
N-(m-tolylaminocarbonyl)-cysteine-S-benzyl,
N-(m-tolylaminocarbonyl)-methionine,
N-(m-tolylaminocarbonyl)-tyrosine,
N-(p-tolylaminocarbonyl)-phenylalanine,
N-(p-tolylaminocarbonyl)-cysteine-S-benzyl,
N-(p-tolylaminocarbonyl)-methionine,
N-(p-tolylaminocarbonyl)-methionine,
N-(phenylaminocarbonyl)-methionine,
N-(p-tolylaminocarbonyl)-tyrosine,
N-(m-tolylaminocarbonyl)-methionine,
N-(p-tolylaminocarbonyl)-methionine,
N-(phenylaminocarbonyl)-methionine,
N-(m-tolylaminocarbonyl)-valine,
N-(m-tolylaminocarbonyl)-phenylglycine,
N-(m-tolylaminocarbonyl)-tyrosine,
2-O-(phenylaminocarbonyl)-mandelic acid,
2-O-(p-tolylaminocarbonyl)-mandelic acid,
2-O-(m-tolylaminocarbonyl)-mandelic acid,
2-O-(o-tolylaminocarbonyl)-mandelic acid,
2-O-(1-naphthylaminocarbonyl)-mandelic acid,
2-O-(3-isopropenyl-α,α-dimethylbenzylaminocarbonyl)-mandelic acid,
2-O-(benzylaminocarbonyl)-mandelic acid,
2-O-(phenethylaminocarbonyl)-mandelic acid,
2-O-(phenylaminocarbonyl)-lactic acid,
2-O-(p-tolylaminocarbonyl)-lactic acid,
2-O-(m-tolylaminocarbonyl)-lactic acid,
2-O-(o-tolylaminocarbonyl)-lactic acid,
2-O-(1-naphthylaminocarbonyl)-lactic acid,
2-O-(3-isopropenyl-α,α-dimethylbenzylaminocarbonyl)-lactic acid,
2-O-(benzylaminocarbonyl)-lactic acid,
2-O-(phenethylaminocarbonyl)-lactic acid and the like.

Examples of acidic phosphate compounds include methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, isodecyl acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, monobutyl phosphate, dibutyl phosphate, monoisodecyl phosphate, bis(2-ethylhexyl) phosphate and the like.

As the electron-accepting compound, as described above, a compound having a phenolic hydroxyl group is preferable because it can more effectively exhibit thermochromic properties, but aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms , carboxylic acid metal salts, acidic phosphoric acid esters and metal salts thereof, 1,2,3-triazoles and derivatives thereof, and the like.

(Reaction medium that determines the temperature at which the color reaction occurs)
The reversible thermochromic composition includes an electron-accepting compound, an electron-donating color-forming organic compound, and a reaction medium that determines the temperature at which the color reaction of the electron-accepting compound occurs. The reaction medium reversibly causes an electron transfer reaction between the electron-donating color-forming organic compound and the electron-accepting compound within a specific temperature range.

Examples of reaction media include esters, ketones, ethers, alcohols, acid amides, and the like.

The reaction medium has a large hysteresis characteristic with respect to the color density-temperature curve (when the temperature is changed from the low temperature side to the high temperature side, and when the temperature is changed from the high temperature side to the low temperature side, the curve plotting the change in color density due to temperature change) It may be a carboxylic acid ester compound that exhibits a ΔT value (melting point - cloud point) of 5 ° C. or higher and lower than 50 ° C. that can form a reversible thermochromic composition that exhibits color memory.
Examples of such carboxylic acid ester compounds include carboxylic acid esters containing a substituted aromatic ring in the molecule, esters of a carboxylic acid containing an unsubstituted aromatic ring and an aliphatic alcohol having 10 or more carbon atoms, cyclohexyl in the molecule, Carboxylic acid ester containing group, ester of fatty acid with 6 or more carbon atoms and unsubstituted aromatic alcohol or phenol, ester of fatty acid with 8 or more carbon atoms and branched aliphatic alcohol, dicarboxylic acid and aromatic alcohol or branched aliphatic Esters with alcohol, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, dimyristin, distearin, etc. be done.

Further, as the reaction medium, for example, a fatty acid ester compound obtained from an odd-numbered aliphatic monohydric alcohol having 9 or more carbon atoms and an even-numbered aliphatic carboxylic acid having an even number of carbon atoms, n-pentyl alcohol or n-heptyl alcohol and an even-numbered aliphatic carboxylic acid having 10 to 16 carbon atoms and a fatty acid ester compound having 17 to 23 carbon atoms is also effective.
Examples of such aliphatic ester compounds include n-pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caprylate, n-undecyl caprylate, n-tridecyl caprylate, n-pentadecyl caprylate, n-heptyl caprate, n-nonyl caprate, n-undecyl caprate, n-tridecyl caprate, n-pentadecyl caprate, lauric acid n-pentyl, n-heptyl laurate, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, n-heptyl myristate, n-myristate nonyl, n-undecyl myristate, n-tridecyl myristate, n-pentadecyl myristate, n-pentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-undecyl palmitate, n-tridecyl palmitate, n-pentadecyl palmitate, n-nonyl stearate, n-undecyl stearate, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eicosanoate, n-undecyl eicosanoate, n-tridecyl eicosanoate, eicosanoic acid n-pentadecyl, n-nonyl behenate, n-undecyl behenate, n-tridecyl behenate, n-pentadecyl behenate and the like.

Aliphatic ketones having 10 or more carbon atoms are effective as ketones. dodecanone, 3-dodecanone, 4-dodecanone, 5-dodecanone, 2-tridecanone, 3-tridecanone, 2-tetradecanone, 2-pentadecanone, 8-pentadecanone, 2-hexadecanone, 3-hexadecanone, 9-heptadecanone, 2-pentadecanone, 2-octadecanone, 2-nonadecanone, 10-nonadecanone, 2-eicosanone, 11-eicosanone, 2-heneicosanone, 2-docosanone, laurone, stearone and the like.

As ketones, arylalkyl ketones having 12 to 24 carbon atoms, such as n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n -tetradecanophenone, 4-n-dodecaacetophenone, n-tridecanophenone, 4-n-undecanoacetophenone, n-laurophenone, 4-n-decanoacetophenone, n-undecanophenone, 4-n- nonylacetophenone, n-decanophenone, 4-n-octylacetophenone, n-nonanophenone, 4-n-heptylacetophenone, n-octanophenone, 4-n-hexylacetophenone, 4-n-cyclohexylacetophenone, 4-tert-butyl Propiophenone, n-heptaphenone, 4-n-pentylacetophenone, cyclohexylphenyl ketone, benzyl-n-butyl ketone, 4-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone, 1-acetonaphtone, 2-acetonaphtone , cyclopentylphenyl ketone, and the like.

Aliphatic ethers having 10 or more carbon atoms are effective as ethers. Decyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decanediol dimethyl ether, undecanediol dimethyl ether, dodecanediol dimethyl ether, tridecanediol dimethyl ether, decanediol diethyl ether, undecanediol diethyl ether, etc. mentioned.

As alcohols, aliphatic monohydric saturated alcohols having 10 or more carbon atoms are effective. decyl alcohol, octadecyl alcohol, eicosyl alcohol, docosyl alcohol and the like.

Acid amides such as hexanoic acid amide, heptanoic acid amide, octanoic acid amide, nonanoic acid amide, decanoic acid amide, undecanoic acid amide, lauric acid amide, tridecanoic acid amide, myristic acid amide, palmitic acid amide, stearic acid amide , docosanoic acid amide, and the like.

（ここで、Ｒ１は水素原子又はメチル基であり、ｑ１は０～２の整数であり、Ｘ１のいずれか一方は－（ＣＨ２）ｋＯＣＯＲ’又は－（ＣＨ２）ｋＣＯＯＲ’であり、他方は水素原子であり、ｋは０～２の整数であり、Ｒ’は炭素数４以上のアルキル基又はアルケニル基であり、Ｙ１はそれぞれ独立に炭素数１以上４以下のアルキル基若しくはメトキシ基、又はハロゲンであり、ｐ１はそれぞれ独立に０～３の整数である。） Also, the reaction medium may be a compound represented by the following general formula (1).

(Here, R1 is a hydrogen atom or a methyl group, q1 is an integer of 0 to 2, one of X1 is -(CH2)kOCOR' or -(CH2)kCOOR', and the other is a hydrogen atom and k is an integer of 0 to 2, R′ is an alkyl group or alkenyl group having 4 or more carbon atoms, and Y1 is each independently an alkyl group or methoxy group having 1 to 4 carbon atoms, or a halogen and p1 are each independently an integer from 0 to 3.)

The compound represented by the general formula (1) is preferable when R1 is a hydrogen atom because a reversible thermochromic composition having a wider hysteresis width can be obtained. is more preferable.

（ここで、Ｒ１ａは、炭素数８以上のアルキル基又はアルケニル基、好ましくは炭素数１０以上２４以下のアルキル基、更に好ましくは炭素数１２以上２２以下のアルキル基である。） The compound represented by the general formula (1) is more preferably a compound represented by the following general formula (1a).

(Here, R1a is an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 or more and 24 or less carbon atoms, more preferably an alkyl group having 12 or more and 22 or less carbon atoms.)

Examples of compounds represented by the general formula (1a) include 4-benzyloxyphenylethyl octanoate, 4-benzyloxyphenylethyl nonanoate, 4-benzyloxyphenylethyl decanoate, and 4-benzyloxy undecanoate. Phenylethyl, 4-benzyloxyphenylethyl dodecanoate, 4-benzyloxyphenylethyl tridecanoate, 4-benzyloxyphenylethyl tetradecanoate, 4-benzyloxyphenylethyl pentadecanoate, 4-benzyloxy hexadecanoate phenylethyl, 4-benzyloxyphenylethyl heptadecanoate, 4-benzyloxyphenylethyl octadecanoate and the like.

（ここで、Ｒ２は炭素数８以上のアルキル基又はアルケニル基であり、ｐ２はそれぞれ独立に０～３の整数であり、Ｘ２はそれぞれ独立に炭素数１以上４以下のアルキル基、炭素数１以上４以下のアルコキシ基、又はハロゲンである。） Moreover, the reaction medium may be a compound represented by the following general formula (2).

(Here, R2 is an alkyl group or alkenyl group having 8 or more carbon atoms, p2 is each independently an integer of 0 to 3, X2 is each independently an alkyl group having 1 to 4 carbon atoms, 1 4 or less alkoxy groups, or halogen.)

Examples of compounds represented by general formula (2) include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, and dodecane. 1,1-diphenylmethyl acid, 1,1-diphenylmethyl tridecanoate, 1,1-diphenylmethyl tetradecanoate, 1,1-diphenylmethyl pentadecanoate, 1,1-diphenylmethyl hexadecanoate, 1,1-heptadecanoate diphenylmethyl, 1,1-diphenylmethyl octadecanoate, and the like.

（ここで、Ｘ３はそれぞれ独立に炭素数１以上４以下のアルキル基、メトキシ基、又はハロゲン原子のいずれかであり、ｐ３はそれぞれ独立に０～３の整数であり、ｑ３は１以上２０以下の整数である。） Also, the reaction medium may be a compound represented by the following general formula (3).

(Here, X3 is each independently an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, p3 is each independently an integer of 0 to 3, and q3 is 1 to 20 is an integer of

Examples of compounds represented by the general formula (3) include diesters of malonic acid and 2-[4-(4-chlorobenzyloxy)phenyl)]ethanol, and succinic acid and 2-(4-benzyloxyphenyl)ethanol. diester of succinic acid and 2-[4-(3-methylbenzyloxy)phenyl)]ethanol, diester of glutaric acid and 2-(4-benzyloxyphenyl)ethanol, glutaric acid and 2-[4 -(4-chlorobenzyloxy)phenyl)]ethanol, diesters of adipic acid with 2-(4-benzyloxyphenyl)ethanol, diesters of pimelic acid with 2-(4-benzyloxyphenyl)ethanol, Diester of suberic acid and 2-(4-benzyloxyphenyl)ethanol, Diester of suberic acid and 2-[4-(3-methylbenzyloxy)phenyl)]ethanol, Suberic acid and 2-[4-(4 -chlorobenzyloxy)phenyl)]ethanol, diesters of suberic acid with 2-[4-(2,4-dichlorobenzyloxy)phenyl)]ethanol, azelaic acid with 2-(4-benzyloxyphenyl) Diester of ethanol, diester of sebacic acid and 2-(4-benzyloxyphenyl)ethanol, diester of 1,10-decanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, 1,18-octadecanedicarboxylic acid and diesters of acid and 2-(4-benzyloxyphenyl)ethanol, and diesters of 1,18-octadecanedicarboxylic acid and 2-[4-(2-methylbenzyloxy)phenyl)]ethanol.

（ここで、Ｒ４はそれぞれ独立に炭素数１以上２１以下のアルキル基又はアルケニル基であり、ｐ４はそれぞれ独立に１以上３以下の整数である。） Moreover, the reaction medium may be a compound represented by the following general formula (4).

(Here, R4 is each independently an alkyl group or alkenyl group having 1 to 21 carbon atoms, and p4 is each independently an integer of 1 to 3.)

Examples of compounds represented by the general formula (4) include a diester of 1,3-bis(2-hydroxyethoxy)benzene and capric acid and a diester of 1,3-bis(2-hydroxyethoxy)benzene and undecanoic acid. , diester of 1,3-bis(2-hydroxyethoxy)benzene and lauric acid, diester of 1,3-bis(2-hydroxyethoxy)benzene and myristic acid, 1,3-bis(2-hydroxyethoxy) diesters of benzene and palmitic acid, diesters of 1,3-bis(2-hydroxyethoxy)benzene with cyclohexanoic carboxylic acid, diesters of 1,3-bis(2-hydroxyethoxy)benzene with cyclohexanoic acid propionic acid, 1,4-bis(hydroxymethoxy)benzene diester with butyric acid, 1,4-bis(hydroxymethoxy)benzene diester with isovaleric acid, 1,4-bis(2-hydroxyethoxy)benzene diester with acetic acid Diesters, diesters of 1,4-bis(2-hydroxyethoxy)benzene and propionic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and valeric acid, 1,4-bis(2-hydroxyethoxy) ) diesters of benzene and caproic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and caprylic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and capric acid, 1,4 - diesters of bis(2-hydroxyethoxy)benzene with lauric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene with myristic acid, 1,4-bis(2-hydroxyethoxy)benzene with cyclohexanepropion Examples include diesters with acids.

（ここで、Ｘ５はそれぞれ独立に炭素数１以上４以下のアルキル基、炭素数１以上４以下のアルコキシ基、又はハロゲン原子のいずれかであり、ｐ５はそれぞれ独立に０以上３以下の整数であり、ｑ５は１以上２０以下の整数である。） Also, the reaction medium may be a compound represented by the following general formula (5).

(where X5 is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, and p5 is each independently an integer of 0 to 3 and q5 is an integer from 1 to 20.)

Examples of compounds represented by the general formula (5) include diesters of succinic acid and 2-phenoxyethanol, diesters of suberic acid and 2-phenoxyethanol, diesters of sebacic acid and 2-phenoxyethanol, and 1,10-decanedicarboxylic acid. and 2-phenoxyethanol, and diesters of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol.

（ここで、Ｒ６は炭素数４以上２２以下のアルキル基、シクロアルキルアルキル基、シクロアルキル基、炭素数４以上２２以下のアルケニル基のいずれかであり、Ｘ６は水素原子、炭素数１以上４以下のアルキル基、炭素数１以上４以下のアルコキシ基、ハロゲン原子のいずれかであり、ｑ６は０又は１である。） Also, the reaction medium may be a compound represented by the following general formula (6).

(Here, R6 is any one of an alkyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, a cycloalkyl group, or an alkenyl group having 4 to 22 carbon atoms, and X6 is a hydrogen atom and 1 to 4 carbon atoms. any of the following alkyl groups, alkoxy groups having 1 to 4 carbon atoms, and halogen atoms, and q6 is 0 or 1.)

Examples of compounds represented by the general formula (6) include decyl 4-phenylbenzoate, lauryl 4-phenylbenzoate, myristyl 4-phenylbenzoate, cyclohexylethyl 4-phenylbenzoate, octyl 4-biphenylacetate, 4- nonyl biphenylacetate, decyl 4-biphenylacetate, lauryl 4-biphenylacetate, myristyl 4-biphenylacetate, tridecyl 4-biphenylacetate, pentadecyl 4-biphenylacetate, cetyl 4-biphenylacetate, cyclopentyl 4-biphenylacetate, 4-biphenylacetate cyclohexylmethyl, 4-biphenylhexylacetate, 4-biphenylacetate cyclohexylmethyl and the like.

（ここで、Ｒ７は炭素数３以上１８以下のアルキル基、又は炭素数３以上１８以下の脂肪族アシル基のいずれかであり、Ｘ７は水素原子、炭素数１以上３以下のアルキル基、炭素数１又は２のアルコキシ基、ハロゲン原子のいずれかであり、Ｙ７は水素原子、メチル基のいずれかであり、Ｚ７は水素原子、炭素数１以上４以下のアルキル基、炭素数１又は２のアルコキシ基、ハロゲン原子のいずれかである。） Also, the reaction medium may be a compound represented by the following general formula (7).

(Here, R7 is either an alkyl group having 3 to 18 carbon atoms or an aliphatic acyl group having 3 to 18 carbon atoms, X7 is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, carbon an alkoxy group having a number of 1 or 2 or a halogen atom, Y7 is a hydrogen atom or a methyl group, Z7 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or It is either an alkoxy group or a halogen atom.)

Examples of compounds represented by general formula (7) include phenoxyethyl 4-butoxybenzoate, phenoxyethyl 4-pentyloxybenzoate, phenoxyethyl 4-tetradecyloxybenzoate, phenoxyethyl 4-hydroxybenzoate and dodecanoic acid. and dodecyl ether of phenoxyethyl vanillate.

（ここで、Ｒ８は炭素数４以上２２以下のアルキル基、炭素数４以上２２以下のアルケニル基、シクロアルキルアルキル基、シクロアルキル基のいずれかであり、Ｘ８は、それぞれ独立にアルキル基、アルコキシ基、ハロゲン原子のいずれかであり、ｐ８は０又は１であり、ｑ８は０以上５以下であり、ｒ８は０以上４以下である。） Also, the reaction medium may be a compound represented by the following general formula (8).

(Here, R8 is any one of an alkyl group having 4 to 22 carbon atoms, an alkenyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, or a cycloalkyl group, and X8 is each independently an alkyl group, an alkoxy a group or a halogen atom, p8 is 0 or 1, q8 is 0 or more and 5 or less, and r8 is 0 or more and 4 or less.)

Examples of the compound represented by the general formula (8) include benzoic acid ester of octyl p-hydroxybenzoate, benzoic acid ester of decyl p-hydroxybenzoate, p-methoxybenzoic acid ester of heptyl p-hydroxybenzoate, p o-Methoxybenzoate of dodecyl-hydroxybenzoate, benzoate of cyclohexylmethyl p-hydroxybenzoate, and the like.

（ここで、Ｒ９は炭素数３以上１７以下のアルキル基、炭素数３以上８以下のシクロアルキル基、炭素数５以上８以下のシクロアルキルアルキル基であり、Ｘ９は水素原子、炭素数１以上５以下のアルキル基、メトキシ基、エトキシ基、ハロゲン原子であり、ｐ９は１以上３以下の整数である。） Also, the reaction medium may be a compound represented by the following general formula (9).

(Here, R9 is an alkyl group having 3 to 17 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, or a cycloalkylalkyl group having 5 to 8 carbon atoms, X9 is a hydrogen atom, and 1 or more carbon atoms. 5 or less alkyl group, methoxy group, ethoxy group, or halogen atom, and p9 is an integer of 1 or more and 3 or less.)

Examples of compounds represented by the general formula (9) include diesters of 4-phenylphenol ethylene glycol ether and cyclohexanecarboxylic acid, diesters of 4-phenylphenol diethylene glycol ether and lauric acid, and 4-phenylphenol triethylene glycol ether. Diesters of cyclohexanecarboxylic acid, diesters of 4-phenylphenol ethylene glycol ether and octanoic acid, diesters of 4-phenylphenol ethylene glycol ether and nonanoic acid, diesters of 4-phenylphenol ethylene glycol ether and decanoic acid, 4 - Diesters of phenylphenol ethylene glycol ether and myristic acid.

The mixing ratio of the electron-donating color-forming organic compound, the electron-accepting compound, and the reaction medium depends on the concentration, color-change temperature, color-change form, and type of these components. The amount of the electron-accepting compound is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 50 parts by mass or less, more preferably 1 part by mass of the donative color-forming organic compound. is 20 parts by mass or less, and the reaction medium is preferably 1 part by mass or more, more preferably 5 parts by mass or more, preferably 800 parts by mass or less, more preferably 200 parts by mass or less.

The method for encapsulating the reversible thermochromic composition in microcapsules is not particularly limited, and examples thereof include an interfacial polymerization method, an interfacial polycondensation method, an in situ polymerization method, a liquid curing coating method, a phase separation method from an aqueous solution, and an organic solvent. A phase separation method, a melting dispersion cooling method, an air suspension coating method, a spray drying method, and the like, may be appropriately selected depending on the application.

Materials for the microcapsules include organic resins such as epoxy resins, urea resins, urethane resins, and isocyanate resins.

Durability can be imparted by providing a secondary resin film on the surface of the microcapsules according to the purpose, and the surface characteristics can be modified for practical use.

The mass ratio of the microcapsules (that is, the microcapsule wall portion not enclosing the reversible thermochromic composition) and the reversible thermochromic composition is 1 part by mass of the microcapsules, and the reversible thermochromic composition is , preferably 1 part by mass or more, more preferably 1 part by mass or more, preferably 7 parts by mass or less, more preferably 6 parts by mass or less. By adding 7 parts by mass or less of the reversible thermochromic composition to 1 part by mass of the microcapsules, it becomes easy to obtain an appropriate wall thickness without the microcapsule walls becoming too thin. It becomes easy to improve the heat resistance and pressure resistance of the pigment. Moreover, by adding 1 part by mass or more of the reversible thermochromic composition to 1 part by mass of the microcapsules, it becomes easy to increase the color density and vividness when the microcapsule pigment develops color.

The average particle size of the microcapsules is, for example, 0.01 to 50 μm, preferably 0.1 to 30 μm, more preferably 0.5 to 20 μm, which satisfies practical use.

For the average particle size of the microcapsule pigment, for example, the particle area is determined using the image analysis type particle size distribution measurement software "Macview" manufactured by Mountec, Inc., and the projected area circle equivalent diameter (Heywood diameter ) may be calculated and measured as the average particle diameter of particles equivalent to a sphere of equal volume based on that value.

In addition, when the particle diameter of all particles or most of the particles exceeds 0.2 μm, the average particle diameter of the microcapsule pigment can be measured, for example, using a particle size distribution analyzer “Multisizer 4e” manufactured by Beckman Coulter. may be measured as the average particle diameter of particles equivalent to a sphere of equal volume by the Coulter method. In addition, for the microcapsule pigment, for example, laser diffraction/scattering particles manufactured by Horiba, Ltd., which are calibrated based on values measured using a standard sample or a measuring device according to the Coulter method (electrical detection zone method). A volume-based particle size and an average particle size (median size) may be measured using a size distribution measuring apparatus “LA-300”.

A microcapsule pigment can be used individually by 1 type or in combination of 2 or more types. The content of the microcapsule pigment in the ink composition is preferably 3 to 20% by mass, more preferably 5 to 15% by mass, based on the total mass of the ink composition. When the content of the microcapsule pigment is within the above range, the balance between the color-developing property of the microcapsule pigment and the luster of the luster pigment in handwriting becomes better.

The total content of microcapsule pigments and luster pigments in the ink composition is, for example, 2 to 45% by mass, preferably 3 to 40% by mass, more preferably 5 to 30% by mass, relative to the total mass of the ink composition. %. When the total content of the microcapsule pigment and the luster pigment is within the above range, better color developability and luster can be achieved, and better decoloring property and removability can be achieved.

The ratio of the content of the microcapsule pigment to the total content of the luster pigment in the ink composition is, for example, 0.5 to 200, preferably 1 to 150, more preferably 1 to 100, still more preferably 1 0.5 to 50. When the ratio of the content of the microcapsule pigment to the total content of the luster pigment is within the above range, the balance between the color developability of the microcapsule pigment and the luster of the luster pigment in handwriting becomes better.

The ink composition contains at least one thickening agent. By containing a thickener, sedimentation, aggregation, and the like of the bright pigment can be suppressed. The thickener may function as a shear thinning agent. Thickeners include polysaccharides, especially heteropolysaccharides. Specifically, xanthan gum, welan gum, succinoglycan whose constituent monosaccharides are organic acid-modified heteropolysaccharides of glucose and galactose (average molecular weight of about 1 million to 8 million), guar gum, locust bean gum and its derivatives, diutan Gums and the like can be mentioned. Xanthan gum is suitable as the polysaccharide. A thickener can be used individually by 1 type or in combination of 2 or more types.

The content of the thickener in the ink composition is preferably 0.17 to 0.55% by mass, more preferably 0.2 to 0.5% by mass, relative to the total mass of the ink composition. When the content of the thickener is 0.17% by mass or more, sufficient ink viscosity can be easily obtained, and it becomes easy to sufficiently suppress aggregation and sedimentation of the microcapsule pigment and the luster pigment. On the other hand, when the content of the thickener is 0.55% by mass or less, the viscosity of the ink does not become too high, and it is easy to form good handwriting.

A resin having a glass transition temperature (Tg value) of 0° C. or less is applied to the ink composition. When such a resin is applied, when the paper touches the handwriting, it suppresses the transfer of the first bright pigment of the handwriting to the paper surface that touches, and the brightness when the handwriting is thermally discolored by rubbing with a friction member or the like. The removability of organic pigments is improved. The above-described resin prevents the second bright pigment from entering between paper fibers and making it difficult to remove from the handwriting by rubbing. However, it is presumed that the fixability of the luster pigments to the fibers of the paper surface is moderately enhanced to such an extent that the first luster pigment and the second luster pigment are easily detached from the paper surface when the handwriting is rubbed.

When the Tg value of the resin exceeds 0 ° C., the reason is not clear, but when the paper touches the handwriting, the handwriting is suppressed by a friction member or the like while suppressing the transfer of the first bright pigment of the handwriting to the paper surface that touched. It becomes difficult to remove the secondary glitter pigment in the handwriting when rubbed against.
The Tg value of the resin is preferably −100° C. or higher, more preferably −80° C. or higher, and even more preferably −65° C. or higher.

Resins applicable to the ink composition include acrylic resins, urethane resins, styrene-butadiene resins, alkyd resins, sulfonamide resins, maleic acid resins, polyvinyl acetate resins, ethylene vinyl acetate resins, vinyl chloride-vinyl acetate resins, styrene and maleic acid. Copolymer with ester, styrene-acrylonitrile resin, xylene resin, urea resin, urea aldehyde resin, phenol resin, alkylphenol resin, terpene phenol resin, rosin resin, rosin phenol resin, polyvinyl alkyl ether, polyamide resin, polyolefin resin, It preferably contains one or more selected from nylon resins, polyester resins, cyclohexanone-based resins, and the like. Among them, styrene-butadiene resin and ethylene-vinyl acetate resin suppress the transfer of the first bright pigment of the handwriting to the surface of the paper when the paper touches the handwriting, and when the handwriting is rubbed with the friction member, the handwriting is heated. It is preferable because it is highly effective in removing the second bright pigment together with the first bright pigment while discoloring. Preferably, the resin contains styrene-butadiene resin and/or ethylene-vinyl acetate resin, and more preferably consists of styrene-butadiene resin and/or ethylene-vinyl acetate resin.
Also, the resin may be water-soluble, or water-insoluble or poorly water-soluble.
When a water-insoluble or sparingly water-soluble resin is applied to the ink composition, it is preferable to apply a dispersion in which the resin is used as a dispersoid, such as an emulsion, in order to improve the dispersion stability of the resin in the ink composition. . Water-insoluble or sparingly water-soluble resins can also enhance the water resistance of handwriting.
The Tg value of the resin is measured using a dynamic viscoelasticity measuring device Rheogel-E4000 manufactured by UBM Co., Ltd., and the peak of the loss elastic modulus when the resin film is pulled and measured at a frequency of 10 Hz is taken as the glass transition temperature Tg. Ask as

The resin content is preferably 1 to 15% by mass, more preferably 1 to 10% by mass, relative to the total mass of the ink composition. Particularly preferably, it is 2 to 10% by mass. By setting the content of the resin within the above range, it is possible to suppress the transfer of the first bright pigment to the paper surface when the handwriting is touched by the paper, while preventing the second bright pigment from entering between the paper fibers. It becomes easy to remove the bright pigment when holding down and rubbing the handwriting with a friction member or the like.
Specific examples of resins that can be applied to the ink composition include, for example, styrene-butadiene resins, manufactured by Asahi Kasei Corporation: SB latex series (DL-612, A-2730, etc.), manufactured by Zeon Corporation: NipolLX series (LX432M, LX421, etc.). ), etc., of styrene-butadiene resins having a Tg value of 0 ° C. or less, and as ethylene-vinyl acetate resins, ethylene-vinyl acetate resins such as Sumikaflex series (401HQ, 408HQE, etc.) manufactured by Sumitomo Chemical Co., Ltd. can include grades having a Tg value of 0° C. or lower.
Resins that can be applied to the ink composition are not limited to these.

The ink composition may contain a saccharide mixture containing 30% by mass or more of at least one of starch saccharification products with 8 or more sugars and reduced products thereof (hereinafter referred to as saccharides). As a result, it is possible to further improve the drying resistance, and to impart the ability to prevent sagging from the tip of the ballpoint pen.

The sugar mixture preferably contains 50% by mass or more of 8- or more sugars, and more preferably 70% by mass or more of 8- or more sugars. In order to impart drought resistance, it is necessary to form a dry film to some extent. When applied to a ballpoint pen, it tends to hang down when the tip is left facing downward (inverted). In addition, when the sugar content is about 3 to 7 sugars, the water absorption is lower than that of monosaccharides or disaccharides, but sufficient drought resistance is not obtained. Furthermore, if a large amount of addition is attempted in order to obtain sufficient drying resistance, water absorption increases and causes sagging, or the added sugar cannot be completely dissolved, increasing the solid content in the ink composition and increasing the resistance. Dryness may decrease. The higher the molecular weight of sugars, the lower the hygroscopicity and the easier it is to form a dry film. Therefore, by using sugars with 8 or more sugars, it is possible to prevent sagging under high humidity and also to improve drying resistance. improves. Furthermore, performances such as heat resistance, acid resistance, and microbial resistance are improved, and a stable state can be maintained in the ink.

As the octahedral or higher sugars, saccharified starch obtained by enzymatic decomposition of starch or the like, and reduced saccharified starch obtained by reducing the terminal group of the saccharified starch can be used. Moreover, when starch is decomposed, saccharides with various degrees of polymerization are produced. Therefore, it is technically difficult to completely isolate only saccharides having octasaccharides or more, and the production cost is high. Therefore, in the sugar mixture in which saccharides of 7 saccharides or less are present, it is possible to use a mixture containing 30% by mass or more of the saccharides of 8 saccharides or more, thereby sufficiently obtaining the performance in the ink, Drying resistance and anti-sagging performance can be imparted. Sugar mixtures include products obtained by degrading (eg, enzymatically degrading) starch.

The content of the sugar mixture in the ink composition is preferably 0.5 to 10% by mass. If it is 0.5% by mass or more, the improvement of drying resistance is effectively obtained, and if it is 10% by mass or less, the viscosity of the ink composition increases due to blending, which may cause bleeding and bloating. , problems such as hindrance to followability can be easily avoided, and good drying resistance is not adversely affected. The content of the sugar mixture is more preferably 1-8% by weight.

The ink composition may contain known components as long as the effects of the present invention are not impaired. For example, if necessary, cellulose derivatives, polyvinylpyrrolidone, polyvinyl alcohol, etc. can be included.

Furthermore, if necessary, various additives may be included. Additives include higher fatty acids such as oleic acid, nonionic surfactants having long-chain alkyl groups, polyether-modified silicone oils, tri(alkoxycarbonylmethyl) thiophosphite, tri(alkoxycarbonyl) thiophosphite, thiophosphite triesters such as ethyl esters), phosphoric acid monoesters of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers, phosphoric acid diesters of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers, or their Lubricants such as metal salts, ammonium salts, amine salts and alkanolamine salts are included.

In addition, inorganic salts such as sodium carbonate, sodium phosphate, and sodium acetate, pH adjusters such as organic basic compounds such as water-soluble amine compounds, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, and saponin. Antirust agents such as phenolic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl parahydroxybenzoate, 2,3,5,6-tetrachloro-4 - Preservatives or fungicides such as (methylsulfonyl)pyridine, ascorbic acid, ascorbic acid derivatives, natural or synthetic polyphenols, N-vinylpyrrolidone oligomers, kojic acid, hydroxylamines, oxime derivatives, α-glucosylrutin, phosphones acid, phosphinate, sulfite, sulfoxylate, dithionite, thiosulfate, thiourea dioxide, formamidine sulfinic acid, glutathione, n-butyraldehyde and aniline reactants, etc. Foaming agents, dispersing agents, etc. may also be included.

The ink composition contains water, but may contain a water-soluble organic solvent in addition to water. When a water-soluble organic solvent is contained, it is preferably contained within a range that does not cause various problems such as poor ink followability due to an increase in ink viscosity, poor drying of handwriting, bleeding of handwriting, or a water-soluble organic solvent. It may be solvent-free. Examples of water-soluble organic solvents include glycol-based water-soluble organic solvents, and specific examples include ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, Ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol isopropyl methyl ether, triethylene glycol, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol mono Ethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, 1,3-butylene glycol, glycerin, furfuryl alcohol and the like can be mentioned.

The ink composition preferably has a viscosity of 7000 to 25000 mPa·s measured at a shear rate of 0.1 sec ⁻¹ and a viscosity of 17 to 30 mPa·s measured at a shear rate of 1000 sec ⁻¹ . A more preferable viscosity of the ink composition is 7500 to 20000 mPa·s at a shear rate of 0.1 sec ⁻¹ and 20 to 30 mPa·s at a shear rate of 1000 sec ⁻¹ . When the viscosity of the ink composition is within the above range, sedimentation, aggregation, etc. of the bright pigment in the ink composition in a stationary state are sufficiently suppressed, and the ink ejection property from the tip of the ballpoint pen during writing is improved. Easy to form thermochromic handwriting with excellent luster. The viscosity of the ink composition can be adjusted to a desired range by appropriately selecting the ink composition, such as the content of the microcapsule pigment, the luster pigment, and the content of the thickener.
The viscosity can be measured using a rheometer "DHR-2" manufactured by TE Instruments Co., Ltd. when the ink composition is at 20°C.

Further, the water-based ink composition preferably has a shear thinning index n represented by the following formula (1) measured at 20°C of 0.20 to 0.35, more preferably 0.25 to 0.35. is more preferable.
T=KJn (1)
Here, T is the shear stress [N/m ² ], K is the viscosity coefficient (constant), and J is the shear rate [sec ⁻¹ ].
As a result, sedimentation, aggregation, etc. of the bright pigment in the ink composition in a stationary state are sufficiently suppressed, and the ink of the ball-point pen tip is discharged without accumulating in the gap between the ball and the ball gripping portion during writing. , making it easy to form clear handwriting with excellent brilliance and color development.

The shear thinning index n can be measured, for example, using a rheometer "DHR-2" manufactured by TE Instruments Co., Ltd., and shear rates of 0.1 sec ^-1 and 1000 sec ^-1 and The shear stress (shear stress) obtained at each shear rate is applied to the above equation (1) to obtain n.

The ink composition is prepared by adding a luster pigment, a microcapsule pigment, a resin, various additives, etc., if necessary, into an aqueous medium containing water and a water-soluble organic solvent, and stirring. It is prepared by directly adding a dispersion or a thickening agent in which a thickening agent is dispersed to and stirring.

The ink composition can be used as ink for writing instruments such as marking pens, ballpoint pens, fountain pens, and brush pens.

The ink composition can be applied to a writing instrument comprising a barrel containing the ink composition and a pen body for leading out the ink composition contained in the barrel. The ink composition can be contained in, for example, an ink occluding body composed of a bundle of fibers, or can be directly contained in an ink containing tube and contained in a barrel. Also, the pen body can be, for example, a marking pen body, a brush pen body, or a ballpoint pen body. A writing instrument constructed using the ink composition having the above structure can form a handwriting that has good luster and can be thermally discolored, and also forms aggregates of the luster pigment in the ink composition. is suppressed, the ink ejection property from the writing tip is good, and the handwriting formation property is excellent.

The writing instrument may be a marking pen. The structure and shape of the marking pen itself are not particularly limited. As a marking pen, for example, an ink occluding body made of a bundle of fibers is built in a barrel, and a marking pen body made of a fiber processed body in which a capillary gap is formed is attached to the barrel directly or via a relay member. The ink occluding body and the marking pen body are connected to each other through a structure in which the ink occluding body is impregnated with the ink composition. A structure in which ink is directly stored in the ink storage tube can be exemplified.

The marking pen body is a porous member with continuous pores selected from the range of about 30% to 70% in porosity, which has been widely used in the past, such as a resin processed body of fibers, a fusion processed body of heat-fusible fibers, and a felt body. , or a synthetic resin extruded body having a plurality of ink outlet holes extending in the axial direction. The ink occlusion body is made by bundling crimped fibers in the longitudinal direction, and is incorporated in a covering such as a plastic cylinder or a film, and is configured by adjusting the porosity to a range of approximately 40% to 90%. be done. Further, the valve body may be of a pumping type that has been widely used in the past, but it is preferable that the valve body has a spring pressure that can be released by the writing pressure.

The writing instrument may be a ballpoint pen. The structure and shape of the ballpoint pen itself are not particularly limited. A ballpoint pen, for example, has an ink storage tube filled with an ink composition in a barrel, the ink storage tube communicates with a ballpoint pen tip having a ball attached to the tip, and is further stored in the ink storage tube. A structure in which a liquid plug for preventing backflow is in close contact with the end face of the ink composition can be exemplified. A ball-point pen constructed using the ink composition having the constitution described above has good ink ejection properties from the writing tip and excellent handwriting formation properties.

As a ball-point pen tip, for example, a ball-point pen tip is formed by cutting a metal material with a drill or the like, in which a ball is held in a ball-holding portion in which the vicinity of the tip of a metal pipe is pressed and deformed inward from the outer surface. A ball-point pen tip that holds a ball in a ball-holding part, a ball-point pen tip that has a resin ball receiving seat inside a metal or plastic tip, and a spring that urges the ball held by the ball-point pen tip forward. can be applied. The ball is made of cemented carbide, stainless steel, ruby, ceramic, resin, rubber, or the like, and has a diameter of, for example, 0.3 mm or more and 2.0 mm or less, preferably 0.3 mm or more and 1.5 mm or less, more preferably 0.3 mm or more and 2.0 mm or less. A thickness of about 3 mm or more and 1.0 mm or less can be applied.

For the ink storage tube that stores the ink composition, for example, a molding made of thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, nylon, or a metal tubular body is used. In addition to directly connecting the tip to the ink containing tube, the ink containing tube and the tip may be connected via a connecting member (tip holder).

The ball-point pen may have an ink storage tube in the form of a ball-point pen refill, and the ball-point pen refill may be stored in a barrel made of resin, metal, or the like, or the barrel itself with the ball-point pen body attached to the tip portion may be used as the ink reservoir. Alternatively, ink may be filled directly into the barrel.

When the ink storage tube is in the form of a ballpoint pen refill, the ballpoint pen refill includes the ink storage tube that stores the ink composition and the ballpoint pen body that is attached to the ink storage tube directly or via a connecting member and holds the ball rotatably. and

When the ink composition is applied to a retractable ballpoint pen, the structure and shape of the retractable ballpoint pen are not particularly limited. Any structure can be used as long as it has a structure in which the tip of the writing tip protrudes from the opening of the barrel by the operation of the retraction mechanism. Methods of operating the retractable mechanism include, for example, a knock type, a rotating type, a sliding type, and the like. The knock type has a knock part on the rear end of the barrel or on the side of the barrel, and by pressing the knock part, the tip of the writing part is pushed out from the front end opening of the barrel, or a clip part provided on the barrel. A configuration can be exemplified in which the writing tip portion is protruded and retracted from the barrel front end opening portion by pressing. The rotary type can be exemplified by a configuration in which a rotating portion is provided at the rear portion of the barrel, and the writing tip portion is projected and retracted from the front end opening portion of the barrel by rotating the rotating portion. The slide type has a slide part on the side surface of the barrel, and by operating the slide, the writing tip part can be retracted from the front end opening of the barrel, or by sliding a clip part provided on the barrel, writing can be performed. A configuration can be exemplified in which the tip portion is projected and retracted from the front end opening of the barrel. The retractable ballpoint pen is a composite type retractable ballpoint pen in which a plurality of ballpoint pen refills are accommodated in a barrel, and the writing tip of one of the ballpoint pen refills is retracted from the front end opening of the barrel by the operation of the retractable mechanism. good too.

The rear end of the ink composition contained in the ink containing tube is filled with an ink backflow preventer. The ink backflow preventer consists of a non-volatile liquid or a low-volatility liquid. Specifically, petrolatum, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Polyether-modified silicone oil, fatty acid-modified silicone oil, and the like can be mentioned, and one kind can be used alone or two or more kinds can be used in combination. At least one of the nonvolatile liquid and the hardly volatile liquid is preferably thickened to a suitable viscosity by adding a thickening agent. As a thickening agent, silica whose surface is hydrophobically treated, fine particle silica whose surface is methylated, aluminum silicate, swelling mica, bentonite with hydrophobic treatment, clay-based thickeners such as montmorillonite, magnesium stearate, calcium stearate , fatty acid metal soaps such as aluminum stearate and zinc stearate, tribenzylidene sorbitol, fatty acid amides, amide-modified polyethylene waxes, hydrogenated castor oil, dextrin compounds such as fatty acid dextrin, and cellulose compounds. Furthermore, a liquid ink backflow prevention member and a solid ink backflow prevention member can be used together.

The forms of marking pens and ballpoint pens are not limited to those described above, and they may be double-headed writing instruments equipped with pen bodies of different forms or pen bodies that lead out ink compositions of different colors. .

A handwriting obtained by writing on a surface to be written with a writing instrument containing a reversible thermochromic water-based ink composition can be discolored by a heating tool or a cooling tool. Examples of the heating tool include an electric heating discoloring tool equipped with a resistance heating element, a heating discoloring tool filled with hot water, etc., and a hair dryer. Preferably, a friction member is used as a means capable of discoloring by a simple method. be done. That is, the writing instrument may further include a friction member.

As the friction member, an elastic body such as an elastomer, a plastic foam, or a viscoelastic body, which is rich in elasticity and can remove the luster pigment while generating moderate friction and generating frictional heat when rubbed, is suitable. . An eraser can also be used to rub the handwriting, but since eraser shavings are generated at the time of rubbing, the above-described friction member that hardly generates erasing scum is preferably used. Silicone resin, SEBS resin (styrene-ethylene-butadiene-styrene block copolymer), polyester-based resin, α-olefin-based copolymer, etc. are used as the material of the friction member.

The friction member may be a member (friction body) of any shape separate from the writing instrument, and may be combined with the writing instrument to constitute a writing instrument set.
In the case of a writing instrument having a cap, the place where the friction member is provided is not particularly limited. The clip itself can be formed of a friction member, or a friction member can be provided at the cap front end (top) or barrel rear end (portion where the writing tip is not provided).
In the case of a retractable writing instrument, the location where the friction member is provided is not particularly limited. For example, the barrel itself may be made of a friction member, or when a clip is provided, the clip itself may be made of a friction member. A friction member may be provided in the knock portion.

Examples of the cooling device include a cold-heat discoloring device using a Peltier element, a cold-heat discoloring device filled with a refrigerant such as cold water or ice chips, and a refrigerator or freezer.

EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited to these examples. "Parts" are based on mass unless otherwise specified.
The average particle size of the microcapsule pigment in the present invention is the volume-based average particle size (median size). (Electrical detection zone method) A particle size measuring device, a laser diffraction/scattering type particle size distribution measuring device (device name: LA-300, manufactured by HORIBA, Ltd.), and the like can be used.
When a laser diffraction/scattering particle size distribution analyzer is used, the measurement is performed using a measuring instrument calibrated with a standard sample or another measuring instrument such as the Coulter method (electrical detection zone method).
If there is a difference in the numerical values obtained depending on the measuring instrument, the numerical values obtained using the image analysis type particle size distribution measurement software are given priority.
In this example, the laser diffraction/scattering particle size distribution measuring device (device name: LA-300, manufactured by Horiba, Ltd.) calibrated by the Coulter method (electrical detection zone method) was used on a volume basis. The average particle size (median size) and particle size were measured.

Preparation of microcapsule pigment 1 Spiro[5H-(1)benzopyrano[2,3-d]pyrimidine-5,1'(3'H)isobenzofuran]-3'-one as an electron-donating color-forming organic compound, 2-(diethylamino)-8-(diethylamino)-4-methyl 1.0 parts, 1,1-bis(4-hydroxyphenyl)-2-ethylhexane 3.0 parts as an electron-accepting compound, 2,2- A color memory comprising a reversible thermochromic composition having a color memory comprising 5.0 parts of bis(4'-hydroxyphenyl)-hexafluoropropane and 50.0 parts of 4-benzyloxyphenylethyl caprate as a reaction medium. A microcapsule pigment 1 was prepared by encapsulating the reversible thermochromic composition a having properties in microcapsules.
Microcapsule Pigment 1 had an average particle diameter of 2.0 μm, a complete discoloration temperature (t4) of 53° C., and a complete color development temperature (t1) of −20° C. The color changed from pink to colorless as the temperature changed.

Preparation of microcapsule pigment 2 Electron-donating color-forming organic compound and 1.0 parts of 3,6-bis(diphenylamino)fluorane as a component, 1,1-bis(4-hydroxyphenyl)-2 as an electron-accepting compound 3.0 parts of ethylhexane, 5.0 parts of 2,2-bis(4'-hydroxyphenyl)-hexafluoropropane, and 50.0 parts of 4-benzyloxyphenylethyl caprate as a reaction medium. A microcapsule pigment 2 was prepared by encapsulating the reversible thermochromic composition b having in microcapsules.
The microcapsule pigment 2 had an average particle size of 1.8 μm, a complete decoloring temperature (t4) of 55° C., and a complete color developing temperature (t1) of −20° C. The color changed from blue to colorless as the temperature changed.

Preparation of Ink Composition Aqueous ink composition no. 1 to No. 7 was prepared. The numerical values of the compositions in the table represent % by mass, and "-" indicates no addition. In addition, No. 1 to No. 4 corresponds to an example, and No. 5 to No. 7 corresponds to a comparative example.

The details of each component in the table are described below.
(A) First Luminous Pigment 1: Elgy neo SILVER #325; manufactured by Oike Imaging Co., Ltd.; containing aluminum as vapor deposition metal; average particle size 44 µm, average thickness 2 µm
(B) First Luminous Pigment 2: Elgy neo SILVER #500; manufactured by Oike Imaging Co., Ltd.; containing aluminum as vapor deposition metal; average particle size: 28 µm, average thickness: 2 µm
(C) Second Luminous Pigment 1: Iriodin 103; manufactured by Merck; particle size distribution 10 μm to 60 μm
(D) Second bright pigment 2: Iriodin 123; manufactured by Merck; particle size distribution 5 μm to 25 μm
(E) Resin 1: Styrene-butadiene resin; manufactured by Asahi Kasei Corporation; SB latex DL612 (dispersion, resin Tg value: -1°C, active ingredient 48% by mass)
(F) Resin 2: Styrene-butadiene resin; manufactured by Asahi Kasei Corporation; SB latex A2730 (dispersion, resin Tg value: -21°C, active ingredient 50% by mass)
(G) Resin 3: Styrene-butadiene resin; Nippon Zeon Co., Ltd.; NipolLX432M (dispersion, resin Tg value: -55°C, active ingredient 41% by mass)
(H) Resin 4: Ethylene vinyl acetate resin; manufactured by Sumitomo Chemical Co., Ltd.; Sumikaflex 408HQE (dispersion, resin Tg value: -30°C, active ingredient 50% by mass)
(I) Resin 5: Styrene-butadiene resin; Nippon Zeon Co., Ltd.; Nipol 2507H (dispersion, resin Tg value: 58 ° C., active ingredient 66% by mass)
(J) Resin 6: Ethylene vinyl acetate resin; manufactured by Sumitomo Chemical Co., Ltd.; Sumikaflex 850HQ (dispersion, resin Tg value: 30°C, active ingredient 50% by mass)
(K) Thickener: xanthan gum; trade name “Kelzan”; manufactured by Sansho Co., Ltd. (L) Water-soluble organic solvent: glycerin (M) Sugars: dextrin; trade name “Sandec 30”; manufactured by Sanwa Starch Kogyo Co., Ltd. (N) Surfactant: Phosphate ester-based active agent; Trade name "Plysurf AL"; Daiichi Kogyo Seiyaku Kogyo Co., Ltd. (O) pH adjuster: Triethanolamine (P) Preservative: (1,2 -Benzisothiazol-3(2H)-one; trade name "Proxel XL-2"; manufactured by Lonza Japan

Preparation of Ballpoint Pen Refill Each of the obtained ink compositions was filled into an ink storage tube made of polypropylene resin, the tip of which was equipped with a ballpoint pen tip that rotatably held a cemented carbide ball with an outer diameter of 0.7 mm. It was filled with an ink backflow preventer made of a viscous liquid. A tail plug was then fitted to the rear of the pipe to obtain each ballpoint refill.

Production of Ballpoint Pen The obtained ballpoint pen refill was attached to the exterior of a ballpoint pen (trade name: Queserame, manufactured by Pilot Corporation). The ball-point pen has a friction member made of polyester resin at the rear end. The following tests were performed using the obtained ballpoint pen. The results are shown in the table below.

(Evaluation of handwriting brightness)
Straight line writing was performed with the obtained ballpoint pen. The brilliance of the handwriting at that time was visually observed and evaluated according to the following evaluation criteria. As media for the writing test, white paper (writing paper A conforming to JIS P3210) and black paper (manufactured by Nagatoya Shoten Co., Ltd., trade name: color paper B5 medium thickness black, thickness 0.09 mm, density 80 g /m2) was used.
As for the evaluation criteria, A and B were accepted, and C was rejected.
Evaluation Criteria A: A strong brilliance with a metallic luster tone is observed over the entire handwriting.
B: Moderate metallic luster-like brilliance is confirmed.
C: A metallic luster tone is weak, and there is a problem in practical use.

(Evaluation of handwriting color development and handwriting heat discoloration)
Visual observation of the color development of the handwriting obtained in the above evaluation revealed that all of the handwritings formed with the inks Nos. 1 to 7 were clearly colored. Further, when the handwriting formed on the white paper was rubbed with a friction member, the thermal discoloration of the handwriting was clearly visually recognized.

(Evaluation of resin-coated flaky metal pigment transferability)
A blank paper medium for a writing test was filled with the ballpoint pen to form a square-shaped handwriting of 5 mm on a side. After 15 minutes from writing, black paper of the same type as the medium for the writing test was placed on the handwriting, and the black paper was rubbed three times with a weight of 500 g, and then the black paper was visually observed. As for the evaluation criteria, A was accepted and B was rejected.
Evaluation Criteria A: No resin-coated flaky metal pigment was observed. Alternatively, a resin-coated flaky metal pigment is slightly adhered.
B: The resin-coated flaky metal pigment adheres remarkably.

(Evaluation of removability of bright pigment)
"PILOT" was written on the writing test medium (black paper) with the ballpoint pen and left for 15 minutes. Next, the handwriting was rubbed with a friction member with a load of 500 g until the entire handwriting was thermally discolored, and the handwriting was visually observed. As for the evaluation criteria, A was accepted, and B and C were rejected.
A: Brilliant feeling is not confirmed.
B: A mild feeling of brightness due to the pearl pigment can be confirmed.
C: A strong sense of brightness due to the pearl pigment can be confirmed.

(Evaluation of handwriting water resistance)
The letter "Ei" was written on the medium (blank paper) for the writing test with the ball-point pen. No change was observed in the handwritings formed with ink compositions 1 to 4. On the other hand, No. It was confirmed that the handwriting formed with the ink composition of No. 6 had a decrease in color developability and luster. Also, No. The handwritings formed with the ink compositions of Nos. 5 and 7 showed a marked decrease in color developability and luster, and the handwritings were difficult to see.

Claims (6)

a reversible thermochromic microcapsule pigment containing a reversible thermochromic composition comprising an electron-donating color-developing organic compound, an electron-accepting compound, and a reaction medium that determines the temperature at which the color reaction of the two occurs; and a resin-coated microcapsule pigment. a flaky metal pigment, a pigment obtained by coating a transparent base material with a metal oxide, water, a thickener, and a resin, and the glass transition temperature (Tg value) of the resin is 0 ° C. characterized by
A water-based ink composition for a reversible thermochromic writing instrument. 2. The aqueous ink composition according to claim 1, wherein said resin comprises styrene-butadiene resin and/or ethylene vinyl acetate resin. 3. The water-based ink composition according to claim 1, wherein the resin content is 1 to 15% by mass based on the total weight of the water-based ink composition. A writing instrument containing the water-based ink composition according to any one of claims 1 to 3. 5. A writing instrument as claimed in claim 4, comprising a friction member. 6. The writing instrument according to claim 4 or 5, which is a ballpoint pen.

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