KR102404914B1 - A aqueous ink composition with excellent gloss - Google Patents

Abstract

The present invention relates to a high-gloss aqueous ink composition, and more particularly, to a high-gloss aqueous ink composition comprising purified water, a color-changing pigment, glossy particles, a moisturizing agent and a thickener.
The present invention can provide a high-gloss aqueous ink composition that is excellent in glossiness, stability over time, and writing properties, and can discolor the image or handwriting by rubbing the image or handwriting formed by the ink with a friction agent.

Description

High gloss aqueous ink composition {A aqueous ink composition with excellent gloss}

The present invention relates to a high-gloss aqueous ink composition, and more particularly, to a high-gloss aqueous ink composition comprising purified water, a color-changing pigment, glossy particles, a moisturizing agent and a thickener.

Aromatic solvents such as xylene and toluene used in writing instrument inks and inkjet printing inks are harmful to the human body and cause air pollution.

As a solution to this problem, an aqueous ink composition obtained by changing an aromatic solvent to water or an alcohol-based solvent that is safe for the human body may be used.

In the aqueous ink composition, pigment particles must be stably dispersed as fine particles in water or alcohol, and in order to improve the dispersibility of the pigment and prevent precipitation, it is usually used in mixing with various surfactants, dispersants, binders, and the like.

On the other hand, in a writing instrument including an aqueous ink composition, research on a high-gloss aqueous ink in which the aqueous ink leaking during writing can produce a high-gloss effect is being actively conducted.

A metal powder that reflects light to express luster is used in this aqueous ink for luster. If the particle size of the metal powder is large, sedimentation occurs during storage and blocks the space of the tip, which may cause writing inability. , if the particles are small, the gloss after writing is very weak.

Therefore, it is necessary to develop a technology for an aqueous ink composition that is excellent in glossiness, stability over time, and writing ability, and can discolor the image or handwriting by rubbing the image or handwriting formed by the ink with a friction agent.

Korean Patent Publication No. 10-2017-0060082

The present invention has been devised to solve the above problems, and has excellent glossiness, stability over time, and writing properties, and is a high-gloss water-based material that can discolor the image or handwriting by rubbing the image or handwriting formed by the ink with a friction agent An object of the present invention is to provide an ink composition.

In order to achieve the above object, the present invention provides a high-gloss aqueous ink composition comprising purified water, a color-changing pigment, glossy particles, a moisturizing agent and a thickener.

In one embodiment of the present invention, the composition comprises 5 to 30% by weight of a discoloration pigment, 1 to 20% by weight of glossy particles, 5 to 30% by weight of a moisturizing agent, 0.1 to 5% by weight of a thickener, and the remaining amount of purified water. characterized.

In one embodiment of the present invention, the color-changing pigment comprises: an inner layer of a capsule prepared by adding an emulsifier to a color-changing pigment mixture including wax, leuco dye and a developer and emulsifying; and

It is characterized in that it is in the form of a microcapsule consisting of an outer layer of the capsule formed by curing a thermosetting resin on the outside of the inner layer of the capsule.

In one embodiment of the present invention, the capsule outer layer is characterized in that it comprises glossy particles and a nonionic surfactant.

In one embodiment of the present invention, the glossy particles are characterized in that one or more of mica, aluminum particles, zinc particles, titanium dioxide, tin oxide, zinc oxide, alumina, pearl particles, glass pearls and glitter particles are used. .

The present invention can provide a high-gloss aqueous ink composition that is excellent in glossiness, stability over time, and writing property, and can discolor the image or handwriting by rubbing the image or handwriting formed by the ink with a friction agent.

Hereinafter, the present invention will be described in detail based on Examples. The terms, examples, etc. used in the present invention are merely exemplified to explain the present invention in more detail and help those of ordinary skill in the art to understand, and the scope of the present invention should not be construed as being limited thereto.

Technical terms and scientific terms used in the present invention represent meanings commonly understood by those of ordinary skill in the art to which this invention belongs, unless otherwise defined.

The present invention relates to a high-gloss aqueous ink composition comprising purified water, a color-changing pigment, glossy particles, a moisturizing agent and a thickener.

The composition may include 5 to 30% by weight of a discoloration pigment, 1 to 20% by weight of glossy particles, 5 to 30% by weight of a moisturizing agent, 0.1 to 5% by weight of a thickener, and the remaining amount of purified water.

preparing a color-changing pigment mixture by mixing the color-changing pigment with wax, leuco dye and a color developer;

adding an emulsifier to the color-changing pigment mixture and emulsifying it to form an inner capsule layer;

forming an outer layer of the capsule by adding a thermosetting resin to the inner layer of the capsule and stirring;

preparing a capsule by curing the capsule outer layer; and

It can be prepared through the step of cooling the capsule to prepare a color-changing pigment.

The content of the color-changing pigment is preferably 5 to 30% by weight, and when the content satisfies the above numerical range, color-changing characteristics, glossiness, stability over time, and writing ability can be maximized.

The color-changing pigment has a microcapsule form including wax, leuco dye, and a color developer in an inner layer.

The discoloration pigment in the form of microcapsules is discolored by the phase change of the wax present in the inner layer of the microcapsule, that is, by the action of melting and hardening at the melting point of the wax, the color disappears (becomes transparent) and reappears It is a pigment having the characteristics to be

The phase change of the wax takes place inside the microencapsulated color-changing pigment. When the temperature rises above the melting point of the wax, the inside of the microcapsule melts and loses its color. Conversely, when the temperature falls below the freezing point, it solidifies and the color appears again. This is because the colorless leuco dye, which has the property of giving away electrons, and the developer, which is a substance that accepts electrons, stops the color development when the wax melts, and the color develops again by solidification of the wax.

That is, the discoloration temperature may appear differently depending on the phase change temperature of the wax contained in the discoloration pigment.

In the present invention, the color-changing pigment is included in the aqueous ink composition, and the color-changing pigment included in the handwriting is decolored by frictional heat generated when the friction agent and the handwriting are rubbed, and the color does not return to its original state even if it is cooled after decolorization. do.

That is, if the aqueous ink composition is written on a substrate such as paper or plastic and then rubbed with a friction agent to erase the handwriting, the discoloration pigment included in the handwriting becomes discolored by the frictional heat generated during friction, This will not return to its original state, and the handwriting may be erased.

At this time, if the color development temperature of the wax contained in the color-changing pigment is higher than room temperature, the color of the color-change pigment returns to its original state when cooled to room temperature, so the handwriting on the substrate cannot be erased.

If the color development temperature of the wax contained in the discoloration pigment is lower than room temperature, it has an irreversible characteristic that does not return to the original color even when cooled to room temperature, so the handwriting can be erased.

Waxes used for the production of irreversible pigments include Dodecanol, n-Decanophenone, n-Tetradecanophenone, 2-(4-phenylmethoxyphenyl) Ethyldecanoate (2-(4-Phenylmethoxyphenyl)ethyl decanoate), n-hexanophenone, n-octanophenone, 2-Naphthyl laurate etc. may be used.

The present invention as the wax n-decanophenone (n-Decanophenone), n- tetradecanophenone (n-Tetradecanophenone) and 2- (4-phenylmethoxyphenyl) ethyldecanoate (2- (4-Phenylmethoxyphenyl) ) ethyl decanoate) is preferably selected from one or more.

In the present invention, two or more kinds of waxes having different melting points can be used, and through this, the corresponding handwriting can be effectively erased.

For example, n-decanophenone, n-tetradecanophenone and 2-(4-phenylmethoxyphenyl)ethyldecanoate may be used simultaneously, in which case n-decanophenone, n-tetradecanophenone and The weight ratio of 2-(4-phenylmethoxyphenyl)ethyldecanoate is preferably 30-70:40-80:100. When the weight ratio satisfies the above numerical range, glossiness, stability over time, and writing ability can be maximized.

The leuco dye is 2-anilino-6-dibutylamino-3-methylfluoran (2-Anilino-6-dibutylamino-3-methylfluoran),

3,3-bis(4-dimethyl-aminophenyl)-6-demethylaminophthalide

(3,3-Bis(4-dimethyl-aminophenyl)-6-demethylaminophtalide),

3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide

(3-(4-Diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide),

6'-(diethylamino)-1',2'-benzofluoran (6'-(Diethylamino)-1',2'-benzofluoran), 3,3-bis(1-n-butyl-2-methyl indol-3-yl)phthalide

(3,3-Bis(1-n-butyl-2-methylindol-3-yl)phthalide),

1,3-dimethyl-6-diethylaminofluoran (1,3-Dimethyl-6-Diethylaminofluoran), 2-N,N-dibenzylamino-6-diethylaminofluoran (2-N,N-Dibenzylamino) -6-

diethylaminofluran),

N,N-dimethyl-4-[2-[2-(octyloxy)phenyl]-6-phenyl-4-pyridinyl]-benzeneamine (N,N-dimethyl-4-[2-[2-(octyloxy) )phenyl]-6-phenyl-4-pyridinyl]-Bezenamine) and the like.

The developer is bisphenol A, Bisphenol AF, Bisphenol E, 4,4'-(α-Methylbenzylidene)bisphenol, 4-Hydroxy-4'-Isopropoxy-diphenyl sulfone, Bis-(3-Allyl-4-Hydroxyphenyl)-sulfone etc.

A color-changing pigment mixture may be prepared by mixing the wax, leuco dye and a developer. At this time, after mixing the wax, the leuco dye and the developer, the mixture may be formed by melting the wax by raising the temperature above the melting point of the wax, specifically, above about 100°C.

The color-changing pigment in the form of microcapsules may be a color-changing pigment having a capsule inner layer in an emulsified form of a mixture of wax, leuco dye and a developer, and having an outer capsule outer layer formed of a thermosetting resin on the outside of the microcapsule.

The color-changing pigment mixture preferably contains 5 to 20 parts by weight of leuco dye and 10 to 30 parts by weight of a developer based on 100 parts by weight of the wax, and the color-changing properties, glossiness, chronological stability and writing properties of the color-changing pigment within the above numerical range can be maximized.

An emulsifier may be added to the discoloration pigment mixture and emulsified to form an inner capsule layer.

As the emulsifier, a water-soluble polymer material may be used, and more specifically, a water-soluble polymer material that is an anionic surfactant may be used.

For example, as the water-soluble polymer material, polystyrene sulfonic acid, styrene maleic anhydride, polyvinyl alcohol, etc. may be used, and the weight average molecular weight of the emulsifier is 1,000 to 1,000,000 g/mol. It is preferable in terms of viscosity and emulsification properties.

The emulsifier is preferably used in the form of an aqueous emulsifier solution, and the content of the emulsifier contained in the emulsifier aqueous solution is preferably 1 to 10% by weight.

The content of the emulsifier aqueous solution is preferably 10 to 400 parts by weight based on 100 parts by weight of the wax.

In the present invention, it is preferable to add an emulsifier to the color-changing pigment mixture and emulsify at a speed of 7,000 to 10,000 rpm.

After adding a thermosetting resin to the capsule inner layer and stirring to form an outer capsule layer, the capsule outer layer may be cured to prepare a capsule.

The microcapsule outer layer may be formed of a thermosetting resin to improve durability, heat resistance and solvent resistance of the color-changing pigment, thereby protecting the inner layer by externally applied temperature, pressure, solvent, and the like. If the microcapsule outer layer is formed of a thermoplastic resin, the inner layer may be deformed or damaged by externally applied temperature, pressure, solvent, etc., and thus the discoloration characteristics may be deteriorated.

As the thermosetting resin, melamine resin, urea, phenol resin, benzoguanamine, acetoguanamine, urethane, epoxy, polymethyl methacrylate, polystyrene, etc. may be used.

The content of the thermosetting resin is preferably 10 to 100 parts by weight, more preferably 30 to 50 parts by weight based on 100 parts by weight of the wax. When the content of the thermosetting resin exceeds 100 parts by weight, the color of the discoloration pigment becomes cloudy and agglomeration of the microcapsules may appear in the initial polymerization process, and if it is less than 10 parts by weight, the heat resistance and solvent resistance of the microcapsules are deteriorated.

As the thermosetting resin, a melamine resin and a phenol resin may be used at the same time, and the weight ratio of the melamine resin and the phenol resin is preferably 60 to 80:20 to 40. When the weight ratio satisfies the above numerical range, it is possible to maximize the color-changing characteristics, glossiness, stability over time, and writing properties of the color-changing pigment.

In addition, as the thermosetting resin, a melamine resin, a phenol resin, and polymethyl methacrylate may be used simultaneously, and in this case, the weight ratio of the melamine resin, phenol resin and polymethyl methacrylate is preferably 100: 40 to 60: 10 to 30. . When the weight ratio satisfies the above numerical range, the discoloration characteristics, glossiness, stability over time, and writing properties of the color-changing pigment can be maximized.

The thermosetting resin may be cured while stirring at 70 to 120° C. for 1 to 10 hours to form an outer capsule layer.

In addition, the step of forming the capsule outer layer is preferably performed at pH 4-6.

In addition, the outer layer of the capsule may further comprise glossy particles and a non-ionic surfactant.

The lustrous particles serve to impart luster by reflecting light, and one or more of mica, aluminum particles, zinc particles, titanium dioxide, tin oxide, zinc oxide, alumina, pearl particles, glass pearls and glitter particles may be used. have.

The size of the glossy particles is preferably 10 ~ 100㎛, more preferably 10 ~ 40㎛.

The content of the glossy particles is preferably 1 to 10 parts by weight based on 100 parts by weight of the wax. have.

The nonionic surfactant is a fatty acid of polyoxyethylene sorbitan such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate. Esters may be used.

In addition, as the nonionic surfactant, fatty acid esters of sorbitan such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, and sorbitan monooleate may be additionally used.

In the present invention, as a nonionic surfactant, a fatty acid ester of polyoxyethylene sorbitan and a fatty acid ester of sorbitan can be used simultaneously, wherein the weight ratio of the fatty acid ester of polyoxyethylene sorbitan to the fatty acid ester of sorbitan is 60 to 80: It is preferable that it is 20-40.

The content of the nonionic surfactant is preferably 0.1 to 1 part by weight based on 100 parts by weight of the wax. can

In addition, the capsule outer layer may further include a copolymer of an acrylate group-containing silane coupling agent and an acrylic acid-based monomer.

The acrylate group-containing silane coupling agent includes 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltri ethoxysilane, 3-acryloxypropyltrimethoxysilane, methacryloxymethyltriethoxysilane, and methacryloxymethyltrimethoxysilane.

The acrylic acid-based monomer is acrylic acid, methacrylic acid, carboxyl ethyl acrylate, carboxyl ethyl methacrylate, carboxyl pentyl acrylate, carboxyl pentyl methacrylate, itaconic acid, maleic acid, fumaric acid, methyl acrylic acid, ethyl acrylic acid, butyl acrylic acid, 2-ethyl hexyl acrylic acid, decyl acrylic acid, methyl methacrylic acid, ethyl methacrylic acid, butyl methacrylic acid, 2-ethyl hexyl methacrylic acid, decyl methacrylic acid, and the like.

The weight ratio of the acrylate group-containing silane coupling agent and the acrylic acid-based monomer is preferably 10 to 30:70 to 90.

The content of the copolymer is preferably 1 to 10 parts by weight based on 100 parts by weight of the wax. .

In addition, the capsule outer layer may additionally include a copolymer of an acrylate group-containing silane coupling agent and 2-hydroxyethyl acrylate (HEA).

The weight ratio of the acrylate group-containing silane coupling agent and 2-hydroxyethyl acrylate is preferably 20-40:60-80.

The content of the copolymer is preferably 1 to 10 parts by weight based on 100 parts by weight of the wax. .

In addition, the capsule outer layer may further include an organic acid aqueous solution of 5 to 10% by weight, and the organic acid aqueous solution may improve durability and heat resistance of the capsule outer layer.

Citric acid, acetic acid, tartaric acid, etc. may be used as the organic acid, and the content of the organic acid aqueous solution is preferably 1 to 10 parts by weight based on 100 parts by weight of the wax.

As the organic acid, citric acid and acetic acid may be used simultaneously, and in this case, the weight ratio of citric acid and acetic acid is preferably 60-80:20-40. When the weight ratio satisfies the above numerical range, the discoloration characteristics, glossiness, stability over time, and writing properties of the color-changing pigment can be maximized.

The capsule is cooled to prepare a discolored pigment, and at this time, it is preferable to cool the capsule slowly to room temperature so that the capsules do not agglomerate with each other.

The color-changing pigment of the present invention includes: an inner layer of a capsule prepared by emulsifying and adding an emulsifier to a color-changing pigment mixture including wax, leuco dye and a developer; and

It may be in the form of a microcapsule comprising an outer layer of the capsule formed by curing a thermosetting resin on the outside of the inner layer of the capsule.

In addition, the discoloration pigment may be surface-treated with a copolymer of an acrylate group-containing silane coupling agent and an acrylic acid-based monomer.

The copolymer coated on the surface of the color-changing pigment can improve the color-changing properties by improving the binding force of the composition.

The weight ratio of the acrylate group-containing silane coupling agent and the acrylic acid-based monomer is preferably 10 to 30:70 to 90.

The amount of the copolymer is preferably 1 to 10 parts by weight based on 100 parts by weight of the color-changing pigment, and when the content of the copolymer is less than 1 part by weight, the improvement in bonding strength is insignificant, and when it exceeds 10 parts by weight, the color-changing characteristics are lowered.

In the present invention, the surface of the discoloration pigment may be treated with a copolymer of an acrylate group-containing silane coupling agent and 2-hydroxyethyl acrylate (HEA).

The weight ratio of the acrylate group-containing silane coupling agent and 2-hydroxyethyl acrylate is preferably 20-40:60-80.

The copolymer is used in an amount of 1 to 10 parts by weight based on 100 parts by weight of the color-changing pigment, and when the content is less than 1 part by weight, the effect of addition is insignificant, and when it exceeds 10 parts by weight, the color-changing characteristics are deteriorated.

In the present invention, the surface of the discoloration pigment may be treated with a copolymer of an acrylate group-containing silane coupling agent, an acrylic acid-based monomer, and 2-hydroxyethyl acrylate (HEA).

The weight ratio of the acrylate group-containing silane coupling agent, the acrylic acid-based monomer and 2-hydroxyethyl acrylate is preferably 2 to 10:100:20 to 50.

The copolymer is used in an amount of 1 to 10 parts by weight based on 100 parts by weight of the color-changing pigment, and when the content is less than 1 part by weight, the effect of addition is insignificant, and when it exceeds 10 parts by weight, the color-changing characteristics are deteriorated.

The lustrous particles serve to impart luster by reflecting light, and one or more of mica, aluminum particles, zinc particles, titanium dioxide, tin oxide, zinc oxide, alumina, pearl particles, glass pearls and glitter particles may be used. have.

The size of the glossy particles is preferably 10 ~ 100㎛, more preferably 10 ~ 40㎛.

The content of the glossy particles is preferably 1 to 20% by weight, and when the content satisfies the numerical range, discoloration characteristics, glossiness, stability over time, and writing ability can be maximized.

In the present invention, a mixture of mica and aluminum particles may be used as the glossy particles, and in this case, the weight ratio of the mica and aluminum particles is preferably 60 to 90:10 to 40. When the content satisfies the above numerical range, discoloration characteristics, glossiness, stability over time, and writing properties can be maximized.

The humectant suppresses drying and serves to impart wetting properties, and glycerin, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and the like may be used.

The content of the moisturizing agent is preferably 5 to 30% by weight, and when the content satisfies the numerical range, discoloration characteristics, glossiness, stability over time, and writing ability can be maximized.

The thickener serves to prevent sedimentation of the composition, and guar gum, locust bean gum, carrageenan gum, xanthan gum, gum arabic, tragacanth gum, guar gum, gellan gum, welan gum, dextran, etc. may be used.

The content of the thickener is preferably 0.1 to 5% by weight, and when the content satisfies the numerical range, discoloration characteristics, glossiness, stability over time, and writing ability can be maximized.

In addition, the aqueous ink composition may further include a copolymer of an acrylate group-containing silane coupling agent and an acrylic acid-based monomer.

The weight ratio of the acrylate group-containing silane coupling agent and the acrylic acid-based monomer is preferably 10 to 30:70 to 90.

The content of the copolymer is preferably 1 to 10% by weight, and when the content satisfies the numerical range, discoloration characteristics, glossiness, stability over time, and writing ability can be maximized.

In addition, the composition may further include a copolymer of an acrylate group-containing silane coupling agent and 2-hydroxyethyl acrylate (HEA).

The weight ratio of the acrylate group-containing silane coupling agent and 2-hydroxyethyl acrylate is preferably 20-40:60-80.

The content of the copolymer is preferably 1 to 10% by weight, and when the content satisfies the numerical range, discoloration characteristics, glossiness, stability over time, and writing ability can be maximized.

In addition, the composition may further include a copolymer of an acrylate group-containing silane coupling agent, an acrylic acid-based monomer, and 2-hydroxyethyl acrylate (HEA).

The weight ratio of the acrylate group-containing silane coupling agent, the acrylic acid-based monomer and 2-hydroxyethyl acrylate is preferably 2 to 10:100:20 to 50.

The content of the copolymer is preferably 1 to 10% by weight, and when the content satisfies the numerical range, discoloration characteristics, glossiness, stability over time, and writing ability can be maximized.

In addition, the composition may further include a silane coupling agent oligomer prepared by reacting an acrylate group-containing silane coupling agent, an epoxy group-containing silane coupling agent, and 2-hydroxyethyl acrylate (HEA).

The weight ratio of the acrylate group-containing silane coupling agent, the epoxy group-containing silane coupling agent and 2-hydroxyethyl acrylate is preferably 2-10:100:20-50.

Preferably, the weight average molecular weight of the silane coupling agent oligomer is 1,000 to 50,000 g/mol.

The epoxy group-containing silane coupling agent includes 2-glycidoxyethylmethyldimethoxysilane, 2-glycidoxyethylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyldiethoxy. Silane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3 ,4-epoxycyclohexyl)ethylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane, 3-(3,4-epoxycyclohexyl)propylmethyldimethoxysilane, 3-( 3,4-epoxycyclohexyl)propylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3- (3,4-epoxycyclohexyl)propyltrimethoxysilane, 3-(3,4-epoxycyclohexyl)propyltriethoxysilane, and the like.

The content of the silane coupling agent oligomer is preferably 1 to 10% by weight, and when the content satisfies the above numerical range, discoloration characteristics, glossiness, stability over time, and writing ability can be maximized.

In addition, the aqueous ink composition of the present invention may further include additives such as lubricants, rust inhibitors, preservatives, and surfactants.

The present invention will be described in detail with reference to the following examples. The following examples are only exemplified for the practice of the present invention, and the content of the present invention is not limited by the following examples.

(Example 1) Preparation of emulsifier aqueous solution

Styrene maleic anhydride was added to purified water to prepare 6 wt% of an emulsifier aqueous solution.

After stirring at 90° C. for 10 hours, it was filtered at 40° C. with a GF/A filter (Whatman) to obtain an emulsifier aqueous solution.

(Example 2) Preparation of color-changing pigment

After mixing 100 parts by weight of 2-(4-phenylmethoxyphenyl)ethyldecanoate, 10 parts by weight of crystal violet lactone, and 15 parts by weight of bisphenol AF, the temperature was raised to 130° C. to prepare a color-changing pigment mixture.

The discoloration pigment mixture was added to 100 parts by weight of the emulsifier aqueous solution prepared in Example 1 and emulsified at 70° C. at 8,000 rpm for 5 minutes to form an inner capsule layer.

50 parts by weight of melamine resin was added to the inner layer of the capsule and reacted at 85° C. for 6 hours.

After adding 5 parts by weight of 6% by weight of citric acid and reacting for another 2 hours, it was cooled slowly while stirring at room temperature to prepare a color-changing pigment.

(Example 3) Preparation of color-changing pigment

A discolored pigment was prepared in the same manner as in Example 2, except that 35 parts by weight of melamine resin and 15 parts by weight of phenol resin were used instead of 50 parts by weight of the melamine resin.

(Example 4) Preparation of color-changing pigment

A color-changing pigment was prepared in the same manner as in Example 2, except that 3.5 parts by weight of citric acid and 1.5 parts by weight of acetic acid were used instead of 5 parts by weight of citric acid.

(Example 5) Preparation of color-changing pigment

50 parts by weight of melamine resin, 2 parts by weight of aluminum particles (glossy particles) having a particle diameter of 26 μm, and 0.2 parts by weight of polysorbate 20 (nonionic surfactant) were added to the inner layer of the capsule and reacted at 85° C. for 6 hours. Except for that, a color-changing pigment was prepared in the same manner as in Example 2.

(Example 6) Preparation of aqueous ink composition

20% by weight of the discoloration pigment prepared in Example 2, 5% by weight of mica (glossy particles) having a particle diameter of 25㎛, 15% by weight of glycerin (moisturizer), 0.3% by weight of xanthan gum (thickener), and the remaining amount of purified water were mixed An aqueous ink composition was prepared.

(Example 7) Preparation of aqueous ink composition

20% by weight of the discoloration pigment prepared in Example 3, 5% by weight of mica (glossy particles) having a particle diameter of 25㎛, 15% by weight of glycerin (moisturizer), 0.3% by weight of xanthan gum (thickener) and the remaining amount of purified water were mixed. An aqueous ink composition was prepared.

(Example 8) Preparation of aqueous ink composition

20% by weight of the discoloration pigment prepared in Example 4, 5% by weight of mica (glossy particles) having a particle diameter of 25 μm, 15% by weight of glycerin (moisturizer), 0.3% by weight of xanthan gum (thickener), and the remaining amount of purified water were mixed. An aqueous ink composition was prepared.

(Example 9) Preparation of aqueous ink composition

20% by weight of the discoloration pigment prepared in Example 5, 5% by weight of mica (glossy particles) having a particle diameter of 25 μm, 15% by weight of glycerin (moisturizer), 0.3% by weight of xanthan gum (thickener) and the remaining amount of purified water were mixed. An aqueous ink composition was prepared.

(Example 10) Preparation of aqueous ink composition

An aqueous ink composition was prepared in the same manner as in Example 6 except that 4% by weight of mica and 1% by weight of aluminum particles were used instead of 5% by weight of mica.

(Comparative Example 1) Preparation of color-changing pigment

A color-changing pigment was prepared in the same manner as in Example 2, except that cetyl alcohol was used instead of 2-(4-phenylmethoxyphenyl)ethyldecanoate.

(Comparative Example 2) Preparation of aqueous ink composition

An aqueous ink composition was prepared by mixing 20% by weight of the discoloration pigment prepared in Comparative Example 1, 15% by weight of glycerin (moisturizer), 0.3% by weight of xanthan gum (thickener), and the remaining amount of purified water.

(Glossiness)

The glossiness of the aqueous ink compositions prepared in Examples and Comparative Examples was measured.

After handwriting was given to 20 students, the glossiness of the handwriting was expressed on a 5-point scale.

(Storage stability)

The storage stability of the aqueous ink compositions prepared in Examples and Comparative Examples was measured.

50 ml of the aqueous ink composition was placed in a glass bottle and left for 20 days, and changes in appearance were observed and marked as excellent, excellent, average, and poor.

Excellent: no precipitation, no separation of water and ink layers

Excellent: No precipitation, slight separation of water and ink layers

Normal: There is some precipitation, and the separation of the water and ink layers is remarkable.

Poor: There is a lot of sediment, and the water and ink layers are completely separated

(Writing)

The writing properties of the aqueous ink compositions prepared in Examples and Comparative Examples were measured.

After handwriting was given to 20 students, the handwriting performance was expressed on a 5-point scale.

glossiness storage stability handwriting Example 6 3.6 Great 3.5 Example 7 4.2 eminence 4.1 Example 8 4.1 eminence 4.0 Example 9 4.4 eminence 4.5 Example 10 4.3 eminence 4.2 Comparative Example 2 2.7 error 2.9

As can be seen from Table 2, it can be seen that Examples 6 to 10 are excellent in gloss, storage stability, and writing properties.

On the other hand, it can be seen that Comparative Example 2 is inferior in the above characteristics to that of Example.

Claims (5)

In the high-gloss aqueous ink composition comprising purified water, a color-changing pigment, glossy particles, a moisturizing agent and a thickener,
The composition comprises 5 to 30% by weight of a discoloration pigment, 1 to 20% by weight of glossy particles, 5 to 30% by weight of a moisturizer, 0.1 to 5% by weight of a thickener, and the remainder of purified water,
The discoloration pigment is
an inner layer of a capsule prepared by emulsifying and adding an emulsifier to a color-changing pigment mixture including wax, leuco dye and a developer; and
It is in the form of a microcapsule consisting of an outer layer of the capsule formed by reacting a thermosetting resin, glossy particles, and a nonionic surfactant on the outside of the inner layer of the capsule,
The discoloration pigment has a property of discoloration through a phenomenon in which the color disappears and reappears by the action of melting and hardening at the melting point of the wax,
The capsule outer layer is a high gloss aqueous ink composition, characterized in that 10 to 100 parts by weight of the thermosetting resin, 1 to 10 parts by weight of the glossy particles and 0.1 to 1 parts by weight of the nonionic surfactant are used based on 100 parts by weight of the wax.
delete delete delete The method of claim 1,
The high-gloss aqueous ink composition, characterized in that at least one of mica, aluminum particles, zinc particles, titanium dioxide, tin oxide, zinc oxide, alumina, pearl particles, glass pearls and glitter particles is used.