JP2003055593A - Writing water-based ink composition capable of being erased with eraser and pen having the same therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an erasable ink composition whose handwritings formed on paper can easily be erased with an eraser at any early time, and also, after the passage of time, can inhibit the formation of ink composition coating films on the tips of pens having the ink composition therein, and therefore has an excellent writing property, and to provide a pen having the ink composition therein. SOLUTION: The erasable writing ink composition which can be erased with the eraser comprises, at least, film-forming resin particles having a glass transition temperature of <=0 deg.C, colored resin particles dyed with a dye, a film formation-inhibiting agent, and water. The pen such as a marking pen has the erasable writing ink composition therein.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an eraser-erasable ink composition for writing and a writing instrument containing the same. More specifically, the present invention relates to an eraser-erasable water-based ink composition for writing in which the handwriting obtained by writing on paper or characters can be easily erased with an eraser, and a writing instrument incorporating the same.

[0002]

2. Description of the Related Art Heretofore, many proposals have been disclosed for ink compositions that give a handwriting that can be erased with an eraser. In particular, in recent years, many proposals have been made for an eraser-erasable water-based ink for writing using water as a main solvent. Has been done. As an example, 1 to 50% of the pigment in the total weight of the ink, 40%
An eraser-erasable ink composition containing 3 to 50% of a resin having a film-forming temperature of ℃ or more, 0.5 to 50% of an organic solvent, and 7 to 60% of water is disclosed (Patent No. 2931901).
Issue). The handwriting obtained by writing with the ink composition does not have a film-forming property at room temperature, and thus the ink penetrates into the paper even when writing on paper or the like, and sufficient erasability cannot be obtained. Separately, it contains a resin having a film forming temperature of 0 ° C. or lower or a glass transition temperature of 0 ° C. or lower, colored spherical fine particles having a particle diameter of 1 to 20 μm, and water, and has an ink viscosity of 5 to 35 mPa · s. An eraser-erasable ink composition is disclosed (Japanese Patent No. 3027484).
Since the ink composition uses a resin having a glass transition temperature of 0 ° C. or lower or a minimum film forming temperature of 0 ° C. or lower, the handwriting obtained by writing with the ink composition is quickly formed on the paper surface. Film is peeled off by rubbing the handwriting with an eraser to show excellent erasability. However, the ink composition forms a film at the writing tip (tip) of a writing instrument containing the ink to easily cause clogging of the tip, and continuous writing is extremely difficult, and the tip is exposed to the atmosphere. There is a drawback that if you leave it in that state for a while, you cannot rewrite it. Further, the disadvantage of the film formation on the chip surface is not only the blur of the handwriting but also the deterioration of the eraser erasability of the handwriting written in such a state. It is considered that this is because the film-forming resin is preferentially accumulated in the formed film and only the ink component excluding the film-forming resin is transferred to the paper surface. Furthermore, since the ink composition uses natural rubber, styrene-butadiene-based copolymer resin, acrylonitrile-butadiene-based copolymer resin or the like as a resin, the handwriting immediately after writing shows good eraser erasability, but There is a possibility that the erasability of the handwriting may deteriorate or become unerasable over time. As yet another example, an eraser-erasable ink composition containing a colorant, a silicone rubber powder, a solvent, and a surfactant as necessary is disclosed (JP 2001-40261 A).
Issue). The ink exhibits good eraser erasability both immediately after writing and after writing with the addition of silicone rubber powder. However, since the particle size of the silicone rubber powder is large, it tends to settle in the ink, and therefore it is necessary to increase the viscosity of the ink. Moreover, unless a large amount of silicone rubber powder is added, the erasability is poor, and there is a risk that smooth writability will be impaired as the viscosity increases. Therefore, the conventional eraser erasable ink composition described above, the eraser erasability of the initial and after the erasing of handwriting, clogging of the ink in the tip when used by incorporating the writing instrument,
Performances such as ink drying resistance on the chip surface and good writing feeling were not sufficiently satisfied.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the problems of conventional eraser-erasable ink compositions, that is, to have excellent writing performance and to eliminate the deterioration of the erasability of handwriting over time. It is what The present inventors focused on the film forming mechanism of the film forming resin particles, which is an important element of eraser erasability, and the ink was not formed on the chip surface, and the ink was formed rapidly on the paper surface. As a result of diligent examination as to whether or not it is not possible, as a result of using a film-forming inhibitor together in an ink composition containing film-forming resin particles having a glass transition temperature of 0 ° C. or less, colored resin particles, and water, the above-mentioned problems It was found that can be solved.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a handwriting containing at least a film-forming resin particle having a glass transition temperature of 0 ° C. or lower, a colored resin particle dyed with a dye, a film-forming inhibitor, and water. Eraser for use Erasable water-based ink composition is required. Furthermore, the film-forming inhibitor is an amphoteric organic compound having a cationic atom and an anionic atom or an atomic group in the molecule, the amphoteric organic compound is an amino acid, an alkyl betaine, an alkylamido betaine, Imidazoline betaines, glycine betaines, one or more compounds selected from amine oxides, the film-forming resin particles are styrene-butadiene copolymer or acrylonitrile-butadiene copolymer, the The colored resin particles are obtained by polymerizing a polymerizable monomer containing at least one of acrylic acid, acrylic acid alkyl ester, methacrylic acid, and methacrylic acid alkyl ester, and have a glass transition temperature of less than 40 ° C. A film-forming inhibitor is added in an amount of 0.02 to 0.6 with respect to 1 part by weight of the film-forming resin particles.
10 parts by weight of the resin composition, and 0.05 to 0.8 parts by weight of the colored resin particles in the ink composition.
To 30 parts by weight, the average particle diameter of the film-forming resin particles and the colored resin particles is in the range of 50 to 500 nm, and the film-forming resin particles and the colored resin particles are produced by an emulsion polymerization method. The ink viscosity is 2
It is required to be 2 to 20 mPa · s at 5 ° C. Furthermore, a writing tool incorporating the above-described eraser-erasable water-based ink composition for writing is required.

The ink composition of the present invention contains film-forming resin particles having a glass transition temperature of 0 ° C. or less in the ink,
In the handwriting formed by the ink, the particles form a film on the paper surface to form a film, and the colorant is fixed in the film. Therefore, without the colorant penetrating inside the paper,
It is a type that erases the handwriting by rubbing the handwriting with an eraser and peeling off the coating film containing the colorant. The film-forming mechanism by the film-forming resin particles will be described in more detail. In the vehicle containing the film-forming resin particles having a glass transition temperature of 0 ° C. or less, thousands of film-forming resin polymer molecules are entangled with each other. It is a liquid in which particles are uniformly dispersed, and contains at least water and film-forming resin particles, as well as water-soluble substances such as emulsifiers and inorganic salts as additives. The film-forming process of the film-forming resin particles proceeds through the following three stages. The first stage is an aggregation process of the film-forming resin particles accompanying evaporation of the medium in the handwriting and permeation into the paper surface. At this stage, if the solid content ratio of the film-forming resin particles in the ink increases due to evaporation of water or penetration into the paper surface, the particles tend to coagulate due to the concerted motion of the particles, forming a hydrogel film. The second stage is a fusion process of the aggregated film-forming resin particles. At this stage, capillaries are formed between the agglomerated particles, and a capillary force that works to attract the particles acts as the water further evaporates. The temperature at this time, the second-order transition temperature of the film-forming resin particles, the glass transition temperature, or,
If the temperature is at least the minimum film forming temperature, the film forming resin particles start to fuse and form a continuous film. The third stage is a mutual diffusion process of the film-forming resin particles. At this stage, when the evaporation of water is completed, most of the additives are confined in the gaps between the particles during the film-forming process of the film-forming resin particles, and some emulsifiers remain at the contact interface between the particles. It is estimated to be.
However, the additive gradually dissolves / diffuses with the lapse of time, and the mutual diffusion of polymer molecule terminals between particles progresses, and the self-adhesion strength between particles gradually increases. Usually, the film formation by the film-forming resin particles is irreversible. Since the self-adhesive strength between the film-forming resin particles becomes strong, the handwriting on the paper surface has a film strength that does not separate even if it is rubbed with a finger or the like.

In the ink composition of the present invention, a film is not formed on the chip surface due to the action of the film-forming inhibitor, and a film is quickly formed on the paper surface. Good writing properties and eraser erasability are achieved at the same time. It is a requirement to meet and is a feature of the present invention. That is, in the process of forming a film with the film-forming resin particles, the system using the film-forming inhibitor of the present invention is
Stabilizing action is given in all steps from the step to the third step. That is, in the first stage, the effect of preventing aggregation, in the second stage, the effect of preventing and suppressing fusion, and in the third stage, the film-forming inhibitor intervenes between the film-forming resin particles, thereby suppressing the strengthening of the film. . The present inventors consider that such a series of actions suppress film formation on the chip surface. In addition, at the time of writing, the film-forming inhibitor rapidly penetrates into the paper surface from the handwriting on the paper surface, so the film-forming inhibitory effect is significantly weakened, and as a result, the film-forming process from the first step to the third step is rapidly performed. It is considered that a continuous and uniform film suitable for eraser erasability is formed.

The above-described behavior on the chip is also confirmed by the following experiment. (A) an aqueous dispersion containing only the film-forming resin, and (B) an aqueous dispersion containing the film-forming resin and a film-forming inhibitor were applied on slide glass, respectively, and left overnight to dry the coating, After that, when water is dropped with a dropper and the coating is rubbed, a uniform and continuous film is peeled off from the coating formed by the aqueous dispersion of (A), and the coating formed by the aqueous dispersion of (B) is removed by water. To re-disperse into the original aqueous dispersion.
From these results, it is clear that the film-forming inhibitor of the present invention exerts a remarkable effect on the suppression / prevention of the film-forming of the film-forming resin particles.

Each component of the ink composition of the present invention will be described below. As the film formation inhibitor, an amphoteric organic compound having a cationic atom and an anionic atom or atomic group in the molecule is preferably used. Examples of the amphoteric organic compound include compounds such as amino acids, alkyl betaines, alkylamido betaines, imidazoline betaines, glycine betaines, amine oxides and the like. Among the amphoteric organic compounds, amino acids and imidazoline betaines are particularly excellent in the effect of suppressing film formation on chips, and the curing of the coating film forming the handwriting is significantly suppressed over time, and is good even after lapse of time. Eraser shows erasability. It is considered that this is because the amphoteric organic compound selected from amino acids and imidazoline betaines is semipermanently retained between the particles in the third step in the film forming process of the film forming resin, that is, in the diffusion process. The amphoteric organic compound used as a specific film-forming inhibitor is shown below. The fatty acid in the examples is a mixture of one or more saturated or unsaturated fatty acids having 6 to 22 carbon atoms, and the alkyl group is Carbon number 6
~ 22. Amino acids include glycine, alanine, valine, leucine, isoleucine, serine, threonine, cysteine, cystine, methionine, aspartic acid, glutamic acid, lysine, arginine, phenylalanine, tyrosine, proline, oxyproline, tryptophan, histidine, threonine, asparagine. , Glutamine, β-aminopropionic acid, γ-aminobutyric acid,
ε-Aminocaproic acid, fatty acid amino acids such as lysine hydrochloride, amino acids such as anthranilic acid, m-aminobenzoic acid, aromatic amino acids such as p-aminobenzoic acid, trimethylglycine, N-coconut oil fatty acid acyl-L-glutamic acid triethanol , N-lauroyl-L-glutamate triethanol, N-coconut oil fatty acid acyl-L-glutamate sodium, N-lauroyl-L-glutamate sodium, N-myristroyl-L-glutamate sodium, N-stearoyl-L-glutamate sodium, N-hardened beef tallow fatty acid acyl-L-glutamate sodium, N-stearoyl-L-glutamate disodium, N-coconut oil fatty acid acyl-L-glutamate potassium, N-coconut oil fatty acid acyl-L-glutamic acid, N
-N-fatty acid acylglutamic acid such as stearoyl-L-glutamic acid or salts thereof, N-fatty acid acylglycine such as N-coconut oil fatty acid acylglycine potassium or salts thereof, N-coconut oil fatty acid acyl-DL-
Examples thereof include amino acid derivatives such as N-fatty acid acylalanine such as alanine triethanol or salts thereof.
Examples of the alkylbetaines include lauryldimethylaminoacetic acid betaine, coconut oil alkylbetaine and other alkyldimethylaminoacetic acid betaines. Examples of the alkylamide betaines include fatty acid amide alkylaminoacetic acid betaines such as coconut oil fatty acid amide propyldimethylaminoacetic acid betaine and lauric acid amidopropyl betaine, and fatty acid amide alkylsulfobetaines such as lauric acid amide propylhydroxysulfobetaine. Examples of the imidazoline betaines include N-fatty acid acyl-N-carboxymethyl-N-hydroxyethyl ethylenediamine sodium (2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine), N-fatty acid acyl-N-carboxy. Ethyl-
N-hydroxyethylethylenediamine sodium (2
-Alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine) and the like. Examples of the glycine betaines include polyalkylpolyaminoalkylglycines such as polyoctylpolyaminoethylglycine, salts of alkyldiaminoethylglycines such as sodium lauryldiaminoethylglycine, and the like. Examples of the amine oxides include dimethyllaurylamine oxide, dimethylalkylamine oxide such as coconut oil alkyldimethylamine oxide, dihydroxyethylalkylamine oxide such as dihydroxyethyllaurylamine oxide, and dimethylalkylethoxyamine oxide such as dimethyllaurylethoxyamine oxide. Is mentioned.

The film-forming inhibitor is used in an amount of 0.02 to 0.6 part by weight, preferably 0.0 to 1 part by weight of the film-forming resin particles.
It is compounded in the range of 3 to 0.3 parts by weight. If the amount is less than 0.02 part by weight, a sufficient effect of suppressing film formation cannot be obtained, and if the amount exceeds 0.6 part by weight, film formation on the paper surface is excessively suppressed, so that the eraser erasability of handwriting is deteriorated. The optimum amount of the film-forming inhibitor added varies depending on the degree of film-forming property of the film-forming resin particles. When colored resin particles having a glass transition temperature of less than 40 ° C. are used, two components are More film-forming inhibitor is needed as it is involved and promotes film formation on the chip.

An amphoteric organic compound is preferably used in order to impart the effect of suppressing the film formation on the surface of the chip. However, even if a conventional surfactant or wetting agent is used instead, the effect of suppressing the film formation and the handwriting effect are reduced. The eraser does not satisfy the erasability and the sufficient effect cannot be obtained. For example, when a nonionic surfactant is used, there is no film formation suppressing effect, and the chips are clogged. When an anionic surfactant is used, it has some effect of suppressing film formation, but the writability is improved, but the eraser erasability of handwriting is not satisfied. When a cationic surfactant is used, the film-forming resin particles and the colored resin particles agglomerate in the ink to increase the viscosity, resulting in poor ink output and difficulty in writing. Further, when the wetting agent is used, not only the effect of preventing film formation on the chip is hardly present, but also the erasability of the eraser of the handwriting is remarkably lowered.

The film-forming resin particles having a glass transition temperature of 0 ° C. or lower will be described. In the ink composition of the present invention, it is preferable to separately prepare a dispersion liquid of the film-forming resin particles and then mix it with various components. As a method for preparing the dispersion liquid, an emulsion polymerization method is preferable. Examples of the emulsion-polymerizable monomer applied to the film-forming resin particles having a glass transition temperature of 0 ° C. or less, such as styrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylbenzyl chloride and vinylpyridine. Monovinylidene aromatic monomers, α, β-ethylenically unsaturated acid alkyl esters such as ethyl acrylate, methyl methacrylate, butyl acrylate and 2-ethylhexyl acrylate, unsaturated esters of saturated carboxylic acids such as vinyl acetate, vinyl chloride , Unsaturated halides such as vinylidene chloride, unsaturated nitriles such as acrylonitrile,
Diene such as butadiene and isoprene, acrylic acid, sodium acrylate, methacrylic acid, itaconic acid, ethylenically unsaturated carboxylic acid such as maleic acid or salts thereof,
Ethylenically unsaturated carboxylic acid amides such as acrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyalkyl acrylates and methacrylates such as hydroxyethyl methacrylate,
Unsaturated aminoalkyl esters such as 2-aminoethylmethacrylate, epoxy functional monomers such as glycidylmethacrylate, unsaturated sulfoalkyl such as 2-sulfoethylmethacrylate, ethylenically unsaturated quaternary ammonium compounds such as vinylbenzyltrimethylammonium chloride. , Vinylpyrrolidone and the like. As the polymerization initiator, a peroxide such as potassium persulfate or cumene hydroperoxide, an azo compound such as azobisisobutyronitrile is used, and a redox catalyst is combined with a reducing agent that accelerates the decomposition of the polymerization initiator. It can also be used. In addition, alkali or the like can be added. As the polymer, styrene-butadiene copolymer resin,
Acrylonitrile-butadiene copolymer is preferably used.

As the emulsifier used for producing the dispersion of the film-forming resin particles, sodium oleate, rosin acid soap, sodium naphthalenesulfonate and its formalin condensate, sodium alkylsulfonate, dialkylsulfosuccinic acid are used. An anion activator such as sodium is used alone, or the anion activator and the nonionic activator are used in combination.

It is preferable that the film-forming resin particles have a glass transition point of 0 ° C. or lower, high rubber elasticity, and low tackiness. The average particle size of the film-forming resin particles in the ink is 50 to 500 nm, preferably 50 to 1
It is 50 nm. If it exceeds 500 nm, the film-forming resin particles are likely to settle or float, and the chips are likely to be clogged.
Since the film-forming resin particles having an average particle diameter of less than 50 nm are difficult to manufacture, they are not required to be practical. The film-forming resin is mixed in the ink in an amount of 10 to 30 parts by weight, preferably 15 to 25 parts by weight. If the amount is less than 10 parts by weight, it may be difficult to form a continuous film on the surface of the paper and the eraser erasability may be impaired.
If it exceeds 30 parts by weight, the total solid content of the ink increases and the viscosity increases, making it difficult to write.

Next, the colored resin particles dyed with a dye will be described. In the ink composition of the present invention, it is preferable that a dispersion liquid of the colored resin particles is separately prepared and then mixed with various components, and an emulsion polymerization method is preferable as a method for preparing the dispersion liquid. An aqueous dispersion of colored resin particles is obtained by dissolving a surfactant and a polymerization initiator in water, adding a polymerization monomer, and then performing a polymerization reaction. The dye is added during or after the polymerization reaction.

Monomers used for the colored resin particles include monovinylidene aromatic monomers such as styrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylbenzyl chloride and vinylpyridine, ethyl acrylate,
Α, β-ethylenically unsaturated acid alkyl esters such as methyl methacrylate, butyl acrylate and 2-ethylhexyl acrylate, unsaturated esters of saturated carboxylic acids such as vinyl acetate, unsaturated halides such as vinyl chloride and vinylidene chloride, acrylonitrile and the like. Unsaturated nitrile, butadiene, diene such as isoprene, acrylic acid, sodium acrylate, methacrylic acid, itaconic acid, ethylenically unsaturated carboxylic acid or salts thereof such as maleic acid, ethylenically unsaturated carboxylic acid amide such as acrylamide, Hydroxyalkyl acrylates and methacrylates such as hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxyethyl methacrylate, and unsaturated aminoalkyl esters such as 2-aminoethyl methacrylate. Examples thereof include epoxy functional monomers such as tellurium and glycidyl methacrylate, unsaturated sulfoalkyl such as 2-sulfoethyl methacrylate, ethylenically unsaturated quaternary ammonium compounds such as vinylbenzyltrimethylammonium chloride, and vinylpyrrolidone. The resin preferably contains one or more resins selected from acrylic acid, alkyl acrylates, methacrylic acid, and alkyl methacrylates. The dye contained in the colored resin particles,
Direct dyes, acid dyes, basic dyes, oil-soluble dyes, disperse dyes and the like can be mentioned, but basic dyes are preferably used.
As the basic dye, thiazole, ketonimine,
Acridine, methine, cyanine, monoazo, disazo,
There are dyes having a xanthine, azine, triarylmethane, xazine, diarylmethane or thiazine structure and the like, and examples thereof include C.I. I. Basic Yellow 1,
2, 11, 35, 40, 51, C.I. I. Basic Orange 14, 21, 22, C.I. I. Basic Red 1,
9, 13, 14, 29, C.I. I. Basic Violet 1, 3, 7, 10, 11, C.I. I. Basic Blue 1, 3, 5, 7, 9, 45, C.I. I. Basic green 1, 4, C.I. I. Basic Brown 1, C.I. I. Basic Black 2, 5 and the like can be mentioned.

The particle size of the colored resin particles is 50 to 500.
nm, preferably 50 to 150 nm. 500 nm
If it exceeds, the colored resin is liable to settle and chips are likely to be clogged. When the thickness is less than 50 nm, the colored resin particles easily penetrate into the paper surface, and it becomes difficult to obtain a satisfactory handwriting eraser erasability. When the glass transition temperature or film-forming temperature of the colored resin particles is less than 40 ° C., it exhibits a certain degree of film-forming property and forms a film together with the film-forming resin on the paper surface. It is effective in preventing the penetration of Furthermore, the coloring resin particles are contained in an amount of 0.05 parts by weight per 1 part by weight of the film-forming resin.
It is preferably added in the range of 0.8 parts by weight.
If it is less than 0.05 parts by weight, it is difficult to obtain a sufficient handwriting density,
If the amount exceeds 0.8 parts by weight, the film-forming resin particles cannot effectively contain the colorant resin particles, and excessive coloring resin particles permeate into the inside of the paper, resulting in poor eraser erasability.

As an example of the method for preparing the ink composition,
After dissolving the film-forming inhibitor in water, an aqueous dispersion of film-forming resin,
It is prepared by adding an aqueous dispersion of a colored resin and stirring and mixing. Further, if desired, conventional additives such as antiseptics, antifungal agents, antioxidants, stabilizers, pH adjusters, wetting agents and surfactants can be added. The additive is a preservative or a fungicide such as carboxylic acid, 1,2-
Benzthiazolin-3-one sodium salt, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-
Tetrachloro-4- (methylsulfonyl) pyridine and the like can be used. As the pH adjuster, inorganic salts such as sodium carbonate, sodium phosphate, sodium acetate, etc., water-soluble amine compounds such as monoethanolamine, diethanolamine, triethanolamine, etc. can be applied. As the wetting agent, urea, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, sodium pyrophosphate and the like can be used. Water-soluble organic solvents such as glycerin, ethylene glycol, diethylene glycol, propylene glycol, 2-pyrrolidone and polyethylene glycol can also be used within a range that does not affect the erasability.
As the surface active agent, nonionic surface active agents, anionic surface active agents and cationic surface active agents can be used within a range that does not affect the writability and erasability. Further, a conventionally known water-soluble resin or water-based resin emulsion may be added to the aqueous vehicle medium for the purpose of improving the fluidity of the ink, stabilizing the dispersion, and finely adjusting the film-forming property.

Next, a writing instrument containing an eraser-erasable water-based ink composition for writing will be described. A marking pen having a fiber tip, a felt tip, or a plastic tip attached to a writing tip is suitable as a writing instrument containing the eraser-erasable water-based ink composition for writing of the present invention. The structure of the inside of the barrel of the marking pen includes a structure in which the ink is made to impregnate an ink absorber made of a fiber bundle housed inside the barrel, and ink is supplied to the writing tip, and the ink is directly housed inside the barrel. A structure in which a comb groove-shaped ink flow rate adjusting member or an ink flow rate adjusting member composed of a fiber bundle is interposed, a structure in which ink is directly contained in the shaft cylinder and a predetermined amount of ink is supplied to the writing tip portion by a valve mechanism Can be illustrated. In addition, in a system in which a coloring component in the ink is aggregated or settled in a barrel of a marking pen having a valve mechanism, a stirring bar such as a stirring ball or a stirring bar is housed and the stirring bar is moved. Therefore, the coloring component may be redispersed.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION A writing eraser-erasable aqueous ink composition of the present invention is prepared by mixing and adding an aqueous dispersion of film-forming resin particles, an aqueous dispersion of colored resin particles, a film-forming inhibitor and water. When the agent is blended, it is prepared by appropriately adding additives and stirring to homogenize it, and then used by filling it in a writing instrument in the form of a marking pen such as a felt-tip pen or felt pen.

[0020]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. The viscosity in the examples is a value measured at 25 ° C. using an ELD viscometer. The compounding numbers in the examples indicate parts by weight.

[0021]   Example 1   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: Nipol LX110, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 80 nm, solid content: 40.5%]   Aqueous dispersion of pink resin particles 16.0   [Product name: SF-5017, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 30%]   Undecyl-N-hydroxyethyl-N-carboxymethyl imidazolinium Betaine solution 7.2   [Brand name: Levon 101-H, Sanyo Kasei Co., Ltd., active ingredient: 25%]   Water 32.8   Total 100.0

The above formulations were mixed and stirred with a three-one motor until homogeneous to obtain an eraser-erasable water-based ink composition for a marking pen. The viscosity of the obtained ink composition was 3.2 mPa · s.

[0023]   Example 2   Aqueous dispersion of styrene-butadiene copolymer 52.0   [Product name: Nipol LX110, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 80 nm, solid content: 40.5%]   Aqueous dispersion of pink resin particles 18.0   [Product name: SF-5017, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 30%]   Undecyl-N-hydroxyethyl-N-carboxymethyl imidazolinium Betaine solution 9.6   [Brand name: Levon 101-H, Sanyo Kasei Co., Ltd., active ingredient: 25%]   Water 20.4   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 4.4 mPa · s.

[0025]   Example 3   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: SB2108, manufactured by Goodyear,   Glass transition temperature: 0 ° C. or lower, particle size: 150 nm or lower, solid content: 41%]   Aqueous dispersion of pink resin particles 16.0   [Glass transition temperature: 2 ° C., particle size: 100 nm, solid content: 30%]   2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium Mbtainine solution 5.1   [Brand name: Levon 105, Sanyo Chemical Co., Ltd., active ingredient: 35%]   Water 34.9   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 4.3 mPa · s.

[0027]   Example 4   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: SB2108, manufactured by Goodyear,   Glass transition temperature: 0 ° C. or lower, particle size: 150 nm or lower, solid content: 41%]   Aqueous dispersion of pink resin particles 16.0   [Brand name: Lumicor NKW-3007, manufactured by Nippon Fluorescence Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 41%]   L-arginine 1.8   [Product name: L-arginine, manufactured by Ajinomoto Co., Inc.]   Polyoxyethylene (20) Polyoxypropylene (4) Cetyl ether 0.5   [Product name: PBC-34, manufactured by Nikko Chemicals Co., Ltd.]   Water 37.7   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 4.7 mPa · s.

[0029]   Example 5   Acrylonitrile-butadiene copolymer water dispersion 44.0   [Product name: Nipol 1562, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -21 ° C, particle size: 50 nm, solid content: 41%]   Aqueous dispersion of pink resin particles 16.0   [Brand name: DayGlo ECX-11, manufactured by Air Brown Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 500 nm or less, solid content: 45%]   N-coconut oil fatty acid acyl-DL-alanine triethanolamine liquid 6.0   [Brand name: Amilite ACT-12, manufactured by Ajinomoto Co., Inc., active ingredient: 30%]   Water 34.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 4.0 mPa · s.

[0031]   Example 6   Acrylonitrile-butadiene copolymer water dispersion 44.0   [Product name: Nipol 1562, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -21 ° C, particle size: 50 nm, solid content: 41%]   Aqueous dispersion of pink resin particles 16.0   [Glass transition temperature: 12 ° C., particle size: 100 nm, solid content: 30%]   Lauryl dimethylamino acetic acid betaine solution 5.1   [Brand name: AM301, manufactured by Nikko Chemicals Co., Ltd., active ingredient: 35%]   Water 34.9   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 4.1 mPa · s.

[0033]   Example 7   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: Nipol LX112, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 80 nm, solid content: 40.5%]   Aqueous dispersion of yellow resin particles 16.0   [Product name: SF-5015, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 30%]   Coconut oil fatty acid amide propyl dimethylamino acetic acid betaine solution 6.0   [Brand name: AM3130N, Nikko Chemicals Co., Ltd., active ingredient 30%]   Water 34.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 3.2 mPa · s.

[0035]   Example 8   Styrene-butadiene latex 44.0   [Product name: Nipol LX112, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 80 nm, solid content: 40.5%]   Orange resin particle emulsion 16.0   [Product name: SF-5014, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 30%]   Lauric acid amidopropyl betaine 6.0   [Product name: Levon 2000L, manufactured by Sanyo Kasei Co., active ingredient: 30%]   Water 34.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 3.3 mPa · s.

[0037]   Example 9   Aqueous dispersion of styrene-butadiene copolymer 35.0   [Brand name: Nipol C4850A, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 300 nm, solid content: 70%]   Aqueous dispersion of pink resin particles 16.0   [Product name: DayGlo SPL-11, manufactured by Air Brown Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 350 nm, solid content: 45%]   Dihydroxyethyl lauryl aminoxide solution 5.0   [Product name: Unisafe A-LE, manufactured by NOF Corporation, active ingredient: 40%]   Water 44.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 3.6 mPa · s.

[0039]   Example 10   Acrylonitrile-butadiene copolymer water dispersion 35.0   [Product name: Nipol LX531B, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -12 ° C, particle size: 300 nm, solid content: 66%]   Aqueous dispersion of pink resin particles 14.0   [Product name: SF-7017, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 400 nm, solid content: 50%]   Sodium lauryl dimethylaminoethyl glycine solution 7.0   [Brand name: Levon 15, Sanyo Kasei Co., Ltd., active ingredient: 30%]   Water 44.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 5.0 mPa · s.

[0041]   Comparative Example 1   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: Nipol LX110, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 80 nm, solid content: 40.5%]   Aqueous dispersion of pink resin particles 16.0   [Product name: SF-5017, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 30%]   Water 40.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 7.4 mPa · s.

[0043]   Comparative example 2   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: Nipol LX110, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 80 nm, solid content: 40.5%]   Aqueous dispersion of pink resin particles 16.0   [Product name: SF5017, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 30%]   Glycerin 10.0   Water 30.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 11.7 mPa · s.

[0045]   Comparative Example 3   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: SB2108, manufactured by Goodyear,   Glass transition temperature: 0 ° C. or lower, particle size: 150 nm or lower, solid content: 41%]   Aqueous dispersion of pink resin particles 16.0   [Brand name: Lumicor NKW-3007, manufactured by Nippon Fluorescence Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size, 100 nm, solid content 41%]   Polyoxyethylene (20) Polyoxypropylene (4) Cetyl ether  [Brand name: PBC-34, Nikko Chemicals Co., Ltd.] 1.8   Water 38.2   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 4.5 mPa · s.

[0047]   Comparative Example 4   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: SB2108, manufactured by Goodyear,   Glass transition temperature: 0 ° C. or lower, particle size: 150 nm or lower, solid content: 41%]   Aqueous dispersion of pink resin particles 36.0   [Brand name: Lumicor NKW-3007, manufactured by Nippon Fluorescence Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size, 100 nm, solid content 41%]   2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium Mbtainine solution 5.1   [Brand name: Levon 105, Sanyo Chemical Co., Ltd., active ingredient: 35%]   Water 14.9   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 7.5 mPa · s.

[0049]   Comparative Example 5   Acrylonitrile-butadiene copolymer water dispersion 44.0   [Product name: Nipol 1562, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -21 ° C, particle size: 50 nm, solid content: 41%]   Aqueous dispersion of pink resin particles 16.0   [DayGlo ECX-11, manufactured by Air Brown Co., Ltd.]   N-coconut oil fatty acid acyl-DL-alanine triethanolamine liquid 1.0   [Brand name: Amilite ACT-12, manufactured by Ajinomoto Co., Inc., active ingredient 30%]   Water 39.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 8.9 mPa · s.

[0051]   Comparative Example 6   Aqueous dispersion of styrene-butadiene copolymer 44.0   [Product name: Nipol LX112, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 80 nm, solid content: 40.5%]   Aqueous dispersion of yellow resin particles 16.0   [Product name: SF-5015, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 30%]   Coconut oil fatty acid amide propyl dimethylamino acetic acid betaine solution 40.0   [Brand name: AM3130N, Nikko Chemicals Co., Ltd., active ingredient 30%]   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 6.3 mPa · s.

[0053]   Comparative Example 7   Aqueous dispersion of styrene-butadiene copolymer 22.0   [Product name: Nipol LX112, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 80 nm, solid content: 40.5%]   Aqueous dispersion of orange resin particles 16.0   [Product name: SF-5014, manufactured by Shin Roihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 100 nm, solid content: 30%]   Dipolyoxyethylene (8) alkyl ether phosphoric acid 1.8   [Product name: DDP-8, manufactured by Nikko Chemicals Co., Ltd.]   Water 38.2   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 4.8 mPa · s.

[0055]   Comparative Example 8   Aqueous dispersion of styrene-butadiene copolymer 13.5   [Brand name: Nipol C4850A, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -47 ° C, particle size: 300 nm, solid content: 70%]   Aqueous dispersion of pink resin particles 10.0   [Product name: DayGlo SPL-11, manufactured by Air Brown Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 350 nm, solid content: 45%]   Dihydroxyethyllaurylamine oxide liquid 3.0   [Brand name: Unisafe A-LE, manufactured by NOF Corporation: 40% active ingredient]   Water 73.5   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 1.9 mPa · s.

[0057]   Comparative Example 9   Acrylonitrile-butadiene copolymer aqueous dispersion 50.0   [Product name: Nipol LX531B, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: -12 ° C, particle size: 300 nm, solid content: 66%]   Aqueous dispersion of pink resin particles 14.0   [Brand name: SF-7017, manufactured by Shin Loihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 400 nm, solid content: 50%]   Sodium lauryl dimethylaminoethyl glycine solution 10.0   [Brand name: Levon 15, Sanyo Kasei Co., Ltd., active ingredient: 30%]   Water 26.0   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 10.0 mPa · s.

[0059]   Comparative Example 10   Aqueous dispersion of styrene-butadiene copolymer 34.3   [Brand name: Nipol 2507H, manufactured by Nippon Zeon Co., Ltd.,   Glass transition temperature: 58 ° C., particle size: 250 nm, solid content: 52%]   Aqueous dispersion of pink resin particles 14.0   [Product name: SF7017, manufactured by Shin Loihi Co., Ltd.,   Glass transition temperature: 40 ° C. or higher, particle size: 400 nm, solid content: 50%]   Undecyl-N-hydroxyethyl-N-carboxymethyl imidazolinium Betaine solution 7.2   [Brand name: Levon 101-H, Sanyo Kasei Co., Ltd., active ingredient: 25%]   Water 44.5   Total 100.0

The above-mentioned formulations were mixed and stirred with a three-one motor until they were homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 2.7 mPa · s.

Preparation of Direct Liquid Marking Pen The ink composition of each of Examples 1 to 4 and Comparative Examples 1 to 4 was made to contain ink directly in the barrel, and the ink flow rate adjusting member was a comb groove-like ink flow rate adjusting member. Was filled in a marking pen of a type that supplies ink to a chip formed by binding a fiber bundle provided at the writing tip with a resin. Preparation of Filling Marking Pen A fiber provided at the writing tip by impregnating ink into an ink occlusion body composed of a fiber bundle containing the ink compositions of Examples 5 to 8 and Comparative Examples 5 to 7 respectively It was filled in a marking pen of a type that supplies ink to a chip formed by binding a bundle with resin. Preparation of Pumping Marking Pens The ink compositions of Examples 9 and 10 and Comparative Examples 8 to 10 each had a valve mechanism and a stirring ball inside a barrel, and a fiber bundle provided at the writing tip was bound with a resin. The tip thus formed was pressed against the paper surface at the time of writing to open the valve, and the ink in the barrel was filled in a marking pen of the type to be led to the tip.

Eraser erasability test Initial erasability About 1 mark on the surface of A4 report paper with each marking pen
Write 34 lines of 8 cm, and use the eraser to erase the handwriting on the first line of each of the first, fifth, tenth, and fifteenth sheets, and after 1 minute from the writing, scrape to erase the handwriting. It was judged. Erasability with time The handwriting on the first line of the first sheet of the report paper written in the initial erasability test of the eraser is left at room temperature for 1 day,
After 7 days and 1 month, the erasability of the handwriting was evaluated using an eraser. For Examples 5 to 8 and Comparative Examples 5 to 7, the erasability after 1 day and 7 days was evaluated.

Presence or absence of solid matter generated at the tip of the chip With each marking pen, about 1 is printed on the surface of the A4 report paper.
34 straight lines of 8 cm were written, and the tip of the chip after writing on the 10th sheet was visually observed to determine the presence or absence of solid matter attached to the chips.

Test of Cap-Off Property The cap was removed, and after leaving it for 20 minutes in a horizontal state at room temperature, writing was performed to judge the writability.

Cap-on recovery test After removing the cap and leaving it horizontal for 1 hour at room temperature, it was confirmed that writing was not possible, and the cap was fitted again to judge the writing performance after leaving for 24 hours. did.

Ink Separation Test After the ink composition was left at room temperature for 1 week, the state of the ink was visually observed. In addition, in all of Examples 9 and 10 and Comparative Examples 8 to 9, although the coloring component in the ink settles over time, the settling color component re-disperses due to the movement of the stirring sphere, and thus was excluded from the test.

The test results of Examples 1 to 4 and Comparative Examples 1 to 4 are shown in the following table.

[Table 1]

The test results of Examples 5 to 8 and Comparative Examples 5 to 7 are shown in the following table.

[Table 2]

Examples 9 and 10 and Comparative Examples 8 to 10
The test results of are shown in the table below.

[Table 3]

The judgment symbols in the table are as follows. Eraser erasability test ○: Can be erased △: Handwriting remains ×: Unerasable Presence of solid matter at the tip of the chip ○: No solid matter is generated ×: Solid matter is generated Cap-off test ○: Writing is possible ×: Writing is not possible Cap-on recovery test ○: Writing is possible ×: Writing is not possible Ink separation test ○: No ink separation ×: There is ink separation

[0071]

The writing eraser-erasable water-based ink composition of the present invention contains film-forming resin particles having a glass transition temperature of 0 ° C. or lower, colored resin particles dyed with a dye, a film-forming inhibitor, and water. Therefore, the handwriting formed on the paper surface formed with the ink can be easily erased with an eraser, and moreover, excellent writing performance can be obtained without causing clogging of the tip in a writing instrument containing the ink composition. Have.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C350 GA04 NA19 NC01 NC23                 4J039 AD03 AD05 AD08 AD09 AD10                       AD11 AD12 AD14 AD15 AD22                       AD23 BC19 BC33 BC36 BC51                       BE03 BE04 BE05 BE07 BE08                       BE33 CA06 EA11 EA48 GA26

Claims (11)

[Claims] 1. A writable eraser-erasable water-based ink composition containing at least a film-forming resin particle having a glass transition temperature of 0 ° C. or lower, a colored resin particle dyed with a dye, a film-forming inhibitor, and water. . 2. The water-based ink composition for erasing with an eraser for writing according to claim 1, wherein the film-forming inhibitor is an amphoteric organic compound having a cationic atom and an anionic atom or atomic group in the molecule. 3. The amphoteric organic compound is one or more compounds selected from amino acids, alkyl betaines, alkylamido betaines, imidazoline betaines, glycine betaines, and amine oxides. Erasable water-based ink composition for writing. 4. The writing eraser-erasable aqueous ink composition according to claim 1, wherein the film-forming resin particles are a styrene-butadiene copolymer or an acrylonitrile-butadiene copolymer. 5. The colored resin particles are obtained by polymerizing a polymerizable monomer containing at least one of acrylic acid, alkyl acrylate, methacrylic acid and alkyl methacrylate, and have a glass transition temperature of 40 ° C. The eraser-erasable water-based ink composition for writing according to claim 1, which is less than 1. 6. The film-forming inhibitor is 0.02 to 0.6 part by weight, and the colored resin particle is 0.0, based on 1 part by weight of the film-forming resin particles.
The water-based ink composition according to claim 1, which comprises 5 to 0.8 parts by weight. 7. The water-based ink composition for erasing with an eraser according to claim 1, wherein the film forming resin particles are contained in an amount of 10 to 30 parts by weight in the ink composition. 8. The average particle diameter of the film-forming resin particles and the colored resin particles is in the range of 50 to 500 nm.
An eraser-erasable water-based ink composition for writing as described above. 9. The water-based ink composition for erasing with an eraser according to claim 1, wherein the film-forming resin particles and the colored resin particles are produced by an emulsion polymerization method. 10. The ink viscosity is 2 to 2 at 25 ° C.
The eraser-erasable water-based ink composition for writing according to claim 1, which has a viscosity of 0 mPa · s. 11. A writing instrument comprising the eraser-erasable water-based ink composition for writing according to any one of claims 1 to 10.