JP2003138193A - Water-based ink composition erasable with eraser and writing implement including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-based ink composition in which the handwriting written on the paper can readily be erased with eraser and cannot be peeled off with usual abrasion with fingers or between paper sheets keeping a proper level of handwriting retention, and to provide writing implements with built-in the same. SOLUTION: This water-based ink composition contains colored thermosetting resin particles of which more than 70 wt.% of the particles have the particle size distribution in the range of 2-20 μm and sticky resin particles of which more than 70 wt.% of the particles have the particle size distribution in the range of 2-20 μm. The ink composition is built in writing implements, e.g. marking pens or ball point pens.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an eraser-erasable water-based ink composition for writing and a writing instrument containing the same. More specifically, a handwriting eraser erasable water-based ink having handwriting retainability that the handwriting obtained by writing on paper can be easily erased with an eraser, and the handwriting is not erased by a normal rubbing process between fingers or paper. The present invention relates to a composition and a writing instrument containing the composition.

[0002]

2. Description of the Related Art Conventionally, an ink composition that gives a handwriting that can be erased with an eraser comprises a thermoplastic colored resin particle containing a basic dye and an adhesive resin particle, and the particle distribution of each particle. Is 2 μm to 2
An eraser-erasable water-based ink composition for writing which is contained in an amount of 70% by weight or more in a range of 0 μm is disclosed (JP-A-200).
No. 1-19889). Since the colored resin granules and the adhesive resin granules have a specific particle diameter, the writing eraser erasable water-based ink composition is present between particles and between particles and the paper surface in the handwriting after drying formed on the paper surface. Is a point-adhesive state, and the handwriting can be easily erased with an eraser, and the handwriting is an ink composition having a handwriting retention property which is not erased by a normal finger or the degree of rubbing between papers. However, since the colored resin granules use a thermoplastic resin as a resin containing a dye, the dye may be eluted from the granules under the influence of the solvent in the ink,
Therefore, even if the dye in the handwriting obtained by writing on the paper penetrates into the paper and is erased by the eraser, the handwriting remains and the dye cannot be erased in some cases.

[0003]

DISCLOSURE OF THE INVENTION As a result of further diligent studies on the above-mentioned conventional eraser-erasable ink composition, the present inventors have found that thermosetting colored resin particles containing a dye having a specific particle diameter and an adhesive resin. By using a granular material, it was found that the handwriting after drying formed on the paper surface does not get erased by normal finger or paper rubbing process degree, and the handwriting can be easily erased by rubbing with an eraser. The present invention has been completed.

[0004]

The present invention provides a thermosetting colored resin granule containing a dye, an adhesive resin granule, and water.
A writable eraser-erasable aqueous ink composition comprising at least a water-soluble polar solvent and having a particle distribution of both the thermosetting colored resin particles and the adhesive resin particles in the range of 2 μm to 20 μm of 70% by weight or more. Is a requirement. Furthermore, the dye is a basic dye, the weight ratio of the dye contained in the thermosetting colored resin granules is 0.1 to 20% by weight, and the thermosetting colored resin granules are contained. The thermosetting resin is a guanamine-based resin and / or a melamine-based resin, contains 5 to 30% by weight of thermosetting colored resin particles and 0.5 to 15% by weight of adhesive resin particles, and The weight ratio of the thermosetting colored resin granules to the adhesive resin granules is 100: 2 to 200, and the adhesive resin granules are separated from each other in the handwriting after drying formed on the paper surface. It is also required that the particles and the paper surface exist in a point adhesive state. Further, the invention requires a marking pen containing the above-mentioned writing eraser-erasable water-based ink composition. Further, the ink composition contains a shear thinning agent, and the viscosity at 100 rpm is 25 to
Eraser erasable water-based ink composition for ballpoint pens, which has a shear thinning index of 0.1 to 0.7 and a heat contained in the ink composition of 160 mPa · s (value of EMD type viscometer at 25 ° C.). 80% by weight of the particle distribution of the curable colored resin particles and the adhesive resin particles in the range of 2 μm to 10 μm
The above requirements include a ballpoint pen incorporating the eraser-erasable water-based ink composition for a ballpoint pen.

The thermosetting colored resin particles are particles for imparting a color tone of handwriting, and the particle distribution is 70% by weight or more in the range of 2 μm to 20 μm in order to prevent the particles from penetrating into the paper. Need. If a large amount of thermosetting colored resin particles having a particle diameter of less than 2 μm are present, the particles penetrate into the interior of the paper, making it difficult to erase the handwriting with an eraser. Further, when a large amount of thermosetting colored resin particles having a particle size of more than 20 μm are present, it becomes difficult for the ink to come out from the tip of the writing instrument filled with the ink, and it becomes easy to cause a problem such as faint handwriting and unreadable writing. .

The thermosetting colored resin particles are colored particles for giving a visible handwriting, and have a particle distribution of 2 μm to 20 μm in order to prevent the particles from penetrating into paper.
It is necessary to contain 70% by weight or more in the range. Examples of the thermosetting colored resin particles include colored resin particles in which a dye is homogeneously or heterogeneously dispersed or dissolved in thermosetting resin particles. It is preferable that the dye is homogeneously dissolved in the resin in order to prevent the dye from associating in the resin or being unevenly distributed to impair the color development.

The thermosetting resin constituting the colored resin particles is an epoxy resin, an epoxy acrylate resin, a xylene resin, a toluene resin, a guanamine resin, a melamine resin, a urethane resin, a phenol resin. , Alkyd resins, amide resins, imide resins, polyamide ester resins, urea resins, silicone resins, unsaturated polyester resins and the like.
The thermosetting resin is excellent in solvent resistance and heat resistance as compared with a thermoplastic resin, and is also excellent in migration resistance of the dye contained therein. Therefore, elution of the dye contained therein can be suppressed, It is suitable as a colorant for an eraser-erasable ink composition of the present invention for erasing. Among the thermosetting resins, guanamine-based resins or melamine-based resins are preferably used because they have an excellent function of preventing the dye contained therein from being eluted.

Examples of dyes for coloring the resin include acid dyes, basic dyes, direct dyes and oil-soluble dyes.
Among the dyes, the basic dye is particularly preferably used because it is more likely to bond with the thermosetting resin and less likely to cause the dye to be eluted in the ink composition, as compared with the acid dye and the direct dye.
Examples of the acid dye include Neucoccin (C.I. 16).
255), tartrazine (CI. 19140), acid blue black 10B (CI. 20470), guinea green (CI. 42085), brilliant blue FCF (CI. 42090), acid violet 6BN (C). I.43525), Soluble Blue (C.I. 42755), Naphthalene Green (C.I.
I. 44025), eosin (C.I. 45380),
Phloxine (CI.45410), Erythrosin (CI.45430), Nigrosine (CI.504)
20), acid flavin (CI.56205) and the like. As the basic dye, chrysoidine (C.I.
I. 11270), methyl violet FN (C.I.
42535), crystal violet (C.I. 42)
555), malachite green (C.I. 4200)
0), Victoria Blue FB (C.I. 44045),
Rhodamine B (CI.45170), Acridine Orange NS (CI.46005), Methylene Blue B
(C.I.52015) and the like. The fluorescent basic dyes include C.I. I. BASIC YELLOW
1, C.I. I. BASIC YELLOW 9, C.I.
I. BASIC YELLOW 35, C.I. I. BAS
IC YELLOW 40, C.I. I. BASIC RE
D1, C.I. I. BASIC RED 1-1, C.I. I.
BASIC RED 2, C.I. I. BASIC RED
12, C.I. I. BASIC RED 13, C.I. I.
BASIC RED 14, C.I. I. BASIC RE
D 15, C.I. I. BASIC RED 36, C.I.
I. BASIC VIOLET 7, C.I. I. BASI
C VIOLET 10, C.I. I. BASIC VIO
LET 11, C.I. I. BASIC VIOLET 1
5, C.I. I. BASIC VIOLET 16, C.I. I.
BASIC VIOLET 27, C.I. I. BASIC
ORANGE 15, C.I. I. BASIC ORAN
GE 22, C.I. I. BASICBLUE 1, C.I.
I. BASIC BLUE 3, C.I. I. BASIC
BLUE 7, C.I. I. BASIC BLUE 9,
C. I. BASIC GREEN 1 etc. can be illustrated.
Examples of the direct dye include Congo Red (C.I. 22).
120), Direct Sky Blue 5B (C.I. 24)
400), Violet BB (C.I. 27905),
Direct Deep Black EX (C.I. 3023
5), Kayaras Black G Conch (C.I. 3522)
5), Direct Fast Black G (C.I. 352
55), phthalocyanine blue (C.I. 74180)
Etc. can be illustrated. Examples of the oil-soluble dye include C.I. I. S
OLVENT BLACK 7, C.I. I. SOLVEN
T BLACK 123, C.I. I. SOLVENT B
LUE2, C.I. I. SOLVENT BLUE 25,
C. I. SOLVENT BLUE 55, C.I. I. S
OLVENT BLUE 70, C.I. I. SOLVEN
T RED 8, C.I. I. SOLVENT RED 4
9, C.I. I. SOLVENT RED 100, C.I.
I. SOLVENT VIOLET 8, C.I. I. SO
LVENT VIOLET 21, C.I. I. SOLVE
NT GREEN3, C.I. I. SOLVENT GRE
EN 3, C.I. I. SOLVENT YELLOW 2
1, C.I. I. SOLVENT YELLOW 44,
C. I. SOLVENT YELLOW 61, C.I.
I. SOLVENT ORANGE 37 etc. can be illustrated.

The weight ratio of the dye contained in the thermosetting colored resin granules is preferably 0.1 to 20% by weight. If it is less than 0.1% by weight, it is difficult to obtain a handwriting exhibiting a desired color tone, and if it is more than 20% by weight, the degree of elution becomes severe and it becomes difficult to obtain sufficient erasability of the handwriting. Further, a pigment may be added to the thermosetting colored resin granules if desired, and a thermosetting coloring containing a pigment having a separately prepared particle distribution of 70% by weight or more in a range of 2 μm to 20 μm. Resin granules or thermoplastic colored resin granules can also be added. Examples of the pigment include azo-based, anthraquinone-based, condensed polyazo-based, thioindigo-based, metal complex salt-based, phthalocyanine-based, perinone-based, perylene-based, dioxazine-based and quinacridone-based organic pigments, carbon black, aniline black, ultramarine blue, and yellow. Inorganic pigments such as lead, titanium oxide, iron oxide, etc.,
As a special pigment, metal powder pigments such as aluminum, mica,
It is also possible to use a pearl pigment in which the surfaces of glass pieces and aluminum oxide are coated with a metal oxide such as titanium oxide.

The thermosetting colored resin granules can be obtained by utilizing conventionally known manufacturing methods such as a pulverization method, a polymerization method and a spray drying method. Specific examples of the polymerization method include a suspension polymerization method, a suspension polycondensation method, a dispersion polymerization method, and an emulsion polymerization method. Mostly used in the present invention is 2
In order to obtain a colored granular material having a particle diameter of ˜20 μm, a pulverizing method, a suspension polymerization method, a suspension polycondensation method, a dispersion polymerization method are preferably used, and more preferably a suspension polymerization method, a pulverizing method. Is used. The emulsion polymerization method is not suitable for the preparation of colored resin particles because most of the particle size distribution is obtained as fine particles of 1 μm or less.

The method for preparing the thermosetting colored resin granules into fine particles by a pulverizing method will be explained. The pulverizing method uses a pulverizer to exert a force such as impact, compression, friction or shear on an object to be pulverized. The method of leading solids to destruction. In the present invention, there is a method in which a block of thermosetting colored resin polycondensed in a bulk form is roughly crushed and then finely divided by a pulverizer.

Next, the adhesive resin granules added to the ink composition in combination with the thermosetting colored resin granules will be described. The adhesive resin granules have a role of adhering the thermosetting colored resin granules that do not show adhesion or tackiness to the paper surface to the paper surface and impart light scratch resistance and erasability with an eraser. Have. The adhesive strength of the adhesive resin particles themselves and the blending amount in the ink composition are determined within a good range that satisfies eraser erasability and light abrasion resistance.
The particle size distribution of the adhesive resin granules must be 70% by weight or more in order to prevent or reduce the permeation into the paper surface. The adhesive resin granules are not particularly limited by the manufacturing method as long as at least the surface layer portion has adhesiveness, and a conventionally known resin particle synthesizing method can be used.

Specific examples of the adhesive resin granules include a homogeneous polymer composition in which the entire resin forming the adhesive resin granules has adhesiveness, and the entire surface of the adhesive resin granules is adhered. Coated with a polymer composition having adhesiveness, the adhesive resin granules having a multi-layered structure, at least a part of the surface of which has adhesiveness, at least a part of the surface of the adhesive resin granules is continuous Alternatively, a polymer composition having a tackiness in a discontinuous state may be used.

As the method for obtaining the above-mentioned adhesive resin particles, a suspension polymerization method, a suspension polycondensation method, a suspension addition reaction method, a seed polymerization method, a dispersion polymerization method, a liquid solvent evaporation method, etc. can be applied. . In order to obtain a homogeneous polymer composition in which all of the resins forming the granule have tackiness, a suspension polymerization method is mainly used,
The dispersion polymerization method, the seed polymerization method, the solvent evaporation method in a liquid can be applied, while on the other hand, in order to obtain a particle having a multilayer structure,
A suspension polymerization method, a suspension polycondensation method, a suspension addition reaction method, a seed polymerization method, a dispersion polymerization method, a solvent evaporation method in a liquid may be appropriately combined, or a secondary treatment surface modification means may be applied. it can. Examples of the multilayer structure include those having a hard central portion and a sticky surface portion. The secondary treatment for imparting tackiness refers to a treatment for further imparting tackiness to the primary particles obtained regardless of the presence or absence of tackiness by further modifying the primary particles.

As a method for preparing the adhesive resin particles, at least one polymerization method selected from a suspension polymerization method, a dispersion polymerization method and a seed polymerization method is preferable, and more preferable is the seed polymerization method. , A dispersion polymerization method can be mentioned, and a granular body having a sharp (sharp angle) particle distribution curve (a granular body having a narrow particle distribution) can be obtained, so that the classification treatment after the reaction can be substantially omitted.

The tackiness of the tacky resin particles means
It means the degree to which the material itself can be removed by rubbing with an eraser and which shows the minimum necessary adhesive force against light abrasion. That is, if the adhesive strength is too strong, the erasability of the eraser is lowered, or a strong frictional force with the eraser is required at the time of erasing. On the contrary, if the adhesive strength is too weak, the adhesive resin granules are easily peeled off by light abrasion, so it is necessary to adjust the adhesive strength so as to satisfy good eraser erasability and light abrasion resistance. As an index for imparting suitable tackiness to the adhesive resin particles, the glass transition point of the obtained adhesive resin particles is preferably lower than 40 ° C, more preferably lower than 20 ° C. When an adhesive resin having a glass transition point of higher than 40 ° C. is used, the degree of adhesiveness is generally weak under room temperature conditions and it becomes difficult to bring about light scratch resistance.

The polymers used for preparing the adhesive resin granules are not particularly limited as long as they have adhesiveness, but specific examples of the polymers include acrylic ester resin, acrylic styrene copolymer resin, and acrylic resin. Examples thereof include acid ester copolymer resin, methacrylic acid ester resin, methacrylic acid ester copolymer resin, ethylene vinyl acetate resin, ethylene acrylic copolymer resin, vinyl acetate resin, polyester resin and alkyd resin.

Next, a method of adjusting the thermosetting colored resin particles and the adhesive resin particles to the above-mentioned particle distribution will be described. The thermosetting colored resin particles and the adhesive resin particles can be adjusted to a desired particle distribution by a wet classification method or a dry classification method. As the wet classification method, after dispersing the granular material in a medium such as water, a centrifugal sedimentation method, or
A method of classifying particles by a natural sedimentation method can be applied.
Further, filtration treatment with a filter paper, a filter or the like is also effective for removing coarse particles. On the other hand, the dry classification method uses a variable impactor, a cyclone,
A classification method using a machine such as a Krascron, turbo classifier, or micron separator can be applied.
The classification may be repeated multiple times so that a desired particle size distribution can be obtained.

Since the adhesive resin particles have adhesiveness at room temperature, it is generally difficult to apply dry classification. Therefore, it is preferable to prepare the above-mentioned granules so that 70% by weight or more is contained in the range of 2 μm to 20 μm in the particle preparing step as much as possible. If classification is necessary, a wet classification method can be applied, and a filtering treatment with a filter paper, a filter, a centrifugal sedimentation method, etc. are suitable.

Next, the blending weight of the thermosetting colored resin granules and the adhesive resin granules in the ink composition and their weight ratio will be described. The blending amount of each granular material in the ink composition is 5 for the thermosetting colored resin granular material.
~ 30% by weight, 0.5 to 15% by weight of adhesive resin particles
It is preferable that the weight ratio of the thermosetting colored resin particles to the adhesive resin particles is 100: 2 to 200.
If the thermosetting colored resin granules are less than 5% by weight, good glitter and color density cannot be obtained, and if it exceeds 30% by weight, the solid content ratio in the ink composition becomes high and the ink is ejected smoothly. It becomes easy to interfere. If the content of the adhesive resin particles is less than 0.5% by weight, good light abrasion resistance cannot be obtained, and if it exceeds 15% by weight, it may be difficult to obtain good eraser erasability.
If the mixing ratio with the colored resin particles is less than 100: 2, good light abrasion resistance cannot be obtained, and if it exceeds 100: 200, good eraser erasability may be difficult to obtain. Explaining the morphological characteristics of the handwriting on the paper surface written using the eraser-erasable water-based ink composition for writing, the ink composition containing the thermosetting colored resin granules and the adhesive resin granules is obtained. In the handwriting after drying formed on the paper surface, the particles contained in the ink composition adhere to each other in a point-adhesive state between the particles and between the paper surface and the particles. By such an action, a two-dimensional network structure having the adhesive resin particles as the core is formed continuously or discontinuously on the paper surface. This morphological feature satisfies both good eraser erasability and light abrasion resistance.

The ink composition can be prepared by uniformly mixing and dispersing the thermosetting colored resin particles and the adhesive resin particles in a vehicle containing water and a water-soluble polar solvent. The water-soluble polar solvent is used for the purpose of suppressing the drying of ink at the tip of writing and imparting water resistance to handwriting. As the water-soluble polar solvent, all the conventional general-purpose solvents that are compatible with water are effective, and ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, propylene glycol, butylene glycol, dipropylene glycol, thiodiethylene glycol are effective. , Sorbitol, glycerin,
Polyhydric alcohols such as polyethylene glycol, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethanolamine, 2-pyrrolidone, N-methyl-2-pyrrolidone, dimethylformamide, etc. can be used alone or in combination of two or more. Is preferably 2 to 35% by weight in the ink composition.

If desired, conventional additives such as preservatives, antifoaming agents, antioxidants, stabilizers, pH adjusters and surfactants may be added. As the pH adjuster, inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, and organic basic compounds such as water-soluble amine compounds can be applied to the additives. Benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin and the like can be used as the rust preventive. Examples of antiseptics and antifungal agents include carboxylic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetramethyl benzoate. Chloro-4- (methylsulfonyl) pyridine and the like can be used. As a wetting agent,
Urea, nonionic surfactant, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, sodium pyrophosphate and the like can be used. In addition, fluorine-based surfactants and silicone-based
Nonionic, anionic or cationic surfactants, defoaming agents such as dimethylpolysiloxane, dispersants and the like may be used. The additives are so-called conventional additives, and can be appropriately used from known compounds as needed. Further, a conventionally known water-soluble resin or an aqueous 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 tackiness.

Next, a writing instrument containing an eraser-erasable water-based ink composition for writing will be described. The eraser-erasable water-based ink composition for writing of the present invention has a fiber tip, a felt tip, and a plastic tip attached to the writing tip, and the ink is impregnated into the ink occlusion body composed of the fiber bundle housed inside the barrel, A structure that supplies ink to the writing tip, a structure that stores ink directly inside the barrel, and a structure that interposes a comb groove-shaped ink flow control member or an ink flow control member that consists of fiber bundles, stores ink directly inside the barrel Further, a marking pen having a structure in which a predetermined amount of ink is supplied to the writing tip portion by a valve mechanism can be mentioned.

On the other hand, when the ink composition of the present invention is applied to a ballpoint pen, since relatively large particles are used, the particles tend to settle in the ink composition. For this reason, a shear thinning viscosity-imparting agent is added to the ink composition, and E
Viscosity at 100 rpm using MD type viscometer is 25-16
0 mPa · s and a shear thinning index of 0.1 to
When it is 0.7, it is possible to obtain a writing instrument which is stable with time without sedimentation or separation of the granular material. When the ink viscosity at 100 rpm exceeds 160 mPa · s, the ink dischargeability is deteriorated, and writing becomes impossible or fading occurs.
If it is less than 25 mPa · s, the dispersion stability of the particles cannot be sufficiently maintained. That is, when the shear thinning index is out of the above range, the effect of shear thinning is not proper, and the separation of the thermosetting colored resin granules and the adhesive resin granules is prevented, and the ink dischargeability and the handwriting performance are impaired. The shear thinning index of the above ink is an empirical formula (T = Kj ⁿ : K and n is calculated from rheological measurements by a viscometer such as shear stress value (T) and shear rate value (j). Is a constant) and is the n value calculated by applying

As the shear thinning agent, it is possible to use a conventionally known compound such as xanthan gum,
Welan gum, succinoglycan (average molecular weight of about 1 to 8 million), which is an organic acid-modified heteropolysaccharide whose constituent monosaccharides are glucose and galactose, guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alginic acid alkyl esters, and methacrylic acid. Polymers having a molecular weight of 100,000 to 150,000 containing alkyl ester as a main component, glycomannan, carbohydrates having gelling ability extracted from seaweeds such as agar and carrageenin, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable Examples thereof include acrylic acid polymers, which can be used alone or in combination. Further, as a shear thinning agent, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene castor oil, polyoxyethylene lanolin / lanolin alcohol / beeswax derivative, polyoxyethylene alkyl Ether / polyoxypropylene alkyl ethers, polyoxyethylene alkylphenyl ethers,
Nonionic surfactants having an HLB value selected from fatty acid amides in the range of 8 to 12, neutralized products of dialkyl or dialkenylsulfosuccinic acids, mixtures of N-alkyl-2-pyrrolidone and anionic surfactants, polyvinyl alcohol Examples thereof include a mixture of acrylic resin and acrylic resin, and they can be used alone or in combination. The shear thinning agent is preferably used in the range of 0.1 to 20% by weight in the ink composition.

Next, the particle size of the granules applied to the eraser-erasable water-based ink composition for writing with a ballpoint pen will be explained. Of the thermosetting colored resin granules and the adhesive resin granules contained in the ink composition, Particle distribution is 2 μm to 10
80% by weight or more is preferably contained in the range of μm,
More preferably, 90% by weight in the range of 2 μm to 10 μm
The above is included. The distribution of particles in an ink composition for writing with a ballpoint pen requires a greater restriction on the particle size as compared with other writing instruments, because the particles smoothly pass through the narrow gap near the ball containing section in the ballpoint pen tip section. . Although it depends on the structure of the ball-point pen tip, it is preferable to apply a granular material containing 80% by weight or more in the range of 2 μm to 10 μm. More preferably, a granular material having a particle distribution of 90% by weight or more in the range of 2 μm to 10 μm is applied. This is because if the proportion of particles having a particle size of 10 μm or more increases, coarse particles may accumulate in the vicinity of the ball accommodating portion without passing through, resulting in poor writing. Next, the stabilizer for the adhesive resin particles when preparing the eraser-erasable water-based ink composition for a ballpoint pen will be described. As the ball rotates during writing, the particles tend to aggregate or agglomerate between the adhesive resin particles due to the extreme pressure effect in the vicinity of the ball housing portion.
Therefore, it is preferable to add a stabilizer for the adhesive resin particles to the ink composition. Examples of the stabilizer include anionic surfactants and amphoteric surfactants, preferably amphoteric surfactants or a combination of anionic surfactants and amphoteric surfactants, and adhesive resin particles. It has a remarkable effect of orienting on the body surface and preventing the adhesive resin particles from agglomerating or agglomerating in the vicinity of the ball containing portion.

Examples of the anionic surfactants include alkyl sulfates, polyoxyethylene alkyl ether sulfates, sulfosuccinates, sulfonates, taurine derivatives, sarcosine derivatives and amide ether sulphates.
, Alkyl phosphates, polyoxyethylene alkyl ether phosphates, fatty acid salts, alkyl ether fatty acid salts, etc., sodium lauryl sulfate, triethanolamine lauryl sulfate, sodium myristyl sulfate, sodium polyoxyethylene lauryl ether sulfate, poly Oxyethylene lauryl ether sulfate triethanolamine salt, dioctyl sodium sulfosuccinate, sodium lauryl sulfoacetate, N-lauroylmethyl taurine sodium, N-myristoyl methyl taurine triethanolamine salt, lauroyl sarcosine sodium,
Oleyl sarcosine potassium, myristoyl sarcosine sodium, polyoxy coconut oil fatty acid monoethanolamide sodium sulfate, sodium lauryl phosphate, sodium polyoxyethylene cetyl ether phosphate, polyoxyethylene nonyl phenyl ether phosphate triethanolamine salt, dipolyoxyethylene lauryl ether phosphate triethanol Examples thereof include amine salts, tripolyoxyethylene lauryl ether phosphate triethanolamine salts, coconut oil fatty acid triethanolamine salts, and polyoxyethylene lauryl ether sodium acetate.

Examples of the amphoteric surfactant include alkylbetaine type, alkylaminobetaine type, imidazoline type, glycine type and etheramine oxide type surfactants, and lauryldimethylaminoacetic acid betaine,
Palm oil fatty acid amide propyl dimethylamino acetic acid betaine, lauric acid amide propyl betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, lauryl hydroxysulfobetaine, polyoctyl polyaminoethyl glycine, lauryl dimethyl amine oxide, Examples thereof include polyoxyethylene coconut oil alkyldimethylamine oxide.

The structure and shape of the ball-point pen itself are not particularly limited, and conventional ones can be applied. For example, the ball-point pen has an ink containing tube filled with an ink composition in a barrel, and the ink containing tube is Is a ball-point pen in which a ball is connected to a tip attached to the tip portion, and a backflow prevention liquid stopper is in close contact with the ink end surface.

The ballpoint pen filled with the ink composition will be described in more detail. For the structure of the writing tip (tip), a general-purpose mechanism has been effective in the past, and the vicinity of the tip of the metal pipe is more inward than the outer surface. A chip formed by holding a ball in the ball holding portion that has been deformed by pressing, or a chip formed by holding a ball in a ball holding portion formed by cutting a metal material with a drill or the like, or a metal-made chip. It is possible to apply, for example, a ball or a ball held by a chip formed by cutting a pipe or a metal material, which is biased forward by a spring body. Further, as the balls, those having a diameter of about 0.3 to 1.2 mm, such as cemented carbide, stainless steel, ruby, and ceramic, can be applied.

As the ink containing tube for containing the ink composition, a molded body made of a thermoplastic resin such as polyethylene, polypropylene or polyethylene terephthalate is preferably used in view of low ink evaporation and productivity. Further, the ink containing tube having an inner diameter of 2.5 to 10 mm is preferably used. Furthermore, by using a transparent, colored transparent, or translucent molded body as the ink containing tube, the ink color, the ink remaining amount, etc. can be confirmed. In addition to directly connecting the chip to the ink containing tube, the ink containing tube and the chip may be connected via a connecting member. Incidentally, the ink containing tube may be one in which the refill is housed in the barrel as a form of a refill for a ballpoint pen, or the barrel itself having a tip attached to the tip is used as an ink container in the barrel. The ink may be directly filled. The inner diameter of the refill housed in the barrel is 2.5 to
The inner diameter of the shaft cylinder for directly containing the ink is preferably 4 to 10 mm.

It is preferable that the back end of the ink composition contained in the ink container is filled with an ink backflow preventer. The ink backflow preventer may be liquid or solid, and the liquid ink backflow preventer may be a non-volatile medium such as polybutene or silicone oil, and if desired, silica in the medium, Aluminum silicate or the like can also be added. Further, as the solid ink backflow preventer, a resin molded product can be mentioned. Furthermore, the liquid and solid ink backflow preventives can be used in combination.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION A water-based ink composition for erasing an eraser for writing of the present invention comprises a water and a water-soluble polar solvent in a medium,
A thermosetting colored resin granule containing a basic dye and an adhesive resin granule are added, and when the additive is blended, the additive is appropriately added and prepared by stirring and dispersing.
It is used by filling a writing pen in the form of a ballpoint pen, felt-tip pen, marking pen, fountain pen, brush pen, etc.

[0034]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. Further, the particle size distribution in the examples was measured using a laser diffraction type particle size distribution analyzer [Shimadzu Corporation; SALD 1100]. The compounding numbers in the examples indicate parts by weight.

Example 1 Preparation of Adhesive Resin Granules Water was added to a separable flask (2 liters) equipped with a stirrer.
0 parts were added, and further 0.2 parts of sodium lauryl sulfate and methyl cellulose (trade name: Metroses 90SH-100,
20 parts of Shin-Etsu Chemical Co., Ltd. was dissolved to obtain a dispersion medium. Butyl acrylate 120 parts, methyl methacrylate 10 parts, ethylene glycol dimethacrylate 2 in the dispersion medium
Part, an oil phase solution consisting of 2.0 parts of 2,2′-azobisisobutyronitrile was added, and stirring was continued at 400 rpm so that the average particle size was about 6 μm. Then, the suspension was heated to 70 ° C. under a nitrogen atmosphere and stirring was continued for 6 hours to carry out suspension polymerization. Then, the mixture was cooled to room temperature, diluted with 1000 parts of water, solid-liquid separated by a centrifugal separation method, and the solid content was adjusted to 30% with water to obtain an adhesive resin particle dispersion A.
Got The average particle size of the particles in the adhesive resin particle dispersion A is 7.8 μm, and the particles are 2 μm to 20 μm.
The range was 85% by weight of all the particles.

Preparation of Thermosetting Colored Resin Granules In a reaction vessel, 72 parts of p-toluenesulfonamide, 18 parts of formaldehyde, fluorescent yellow dye [Dialesin Brilliant Yellow 6G, oil-soluble dye, Mitsubishi Chemical Co., Ltd.]
3 parts was added, and the mixture was heated to 150 ° C. and uniformly dissolved, then 18 parts of melamine was added and reacted for 1 hour. Furthermore,
Heat treatment at 150 ° C for 3 hours using a hot air dryer, allow to cool at room temperature, coarsely pulverize with a hammer mill, then finely pulverize with a jet mill, classify with a wind classifier, and heat cure A fluorescent yellow resin granular material A was obtained. The average particle size of the particles in the thermosetting fluorescent yellow resin particles A is 6.
The particle size was 3 μm, and the particles contained 91 wt% of all the particles in the range of 2 μm to 20 μm.

[0037]   Preparation of ink composition   Thermosetting fluorescent yellow resin granular material A 5.0   Adhesive resin particle dispersion A 15.0   Ethylene glycol 10.0   Penetrant 0.3   [Product name: Acetinol EH, Kawaken Fine Chemicals Co., Ltd.]   Silicone defoamer 0.1   Preservative (trade name: Proxel XL-2, manufactured by Zeneca) 0.1   Water 69.5   Total 100.0

The above-mentioned composition was mixed and stirred with a disper until it became homogeneous to obtain an ink composition. The viscosity of the obtained ink composition is 5.8 mPa · s (ELD type viscometer, 2
5 ° C.).

Example 2 Preparation of thermosetting colored resin granules In a reaction vessel, 48 parts of p-toluenesulfonamide, 22 parts of formaldehyde aqueous solution (37%), fluorescent yellow dye [Dialesin Brilliant Yellow 6G, oil-soluble dye, Mitsubishi Chemical Co., Ltd.] 3 parts was added, and the mixture was heated to 150 ° C. and uniformly dissolved, then 41 parts of γ-2,4-diamino-6-triazyl-γ-phenyl-pyroguanamine was added, and the mixture was added for 1 hour. It was made to react. Furthermore, using a hot air dryer, 150
After heat-treating at ℃ for 3 hours and discharging at room temperature, coarsely crushed with a hammer mill, then finely crushed with a jet mill and classified with an air classifier to obtain a thermosetting fluorescent yellow resin granular material B. Got The average particle size of the particles in the thermosetting fluorescent yellow resin particles B was 8.1 μm, and the particles were 2 μm.
88% by weight of all the particles was contained in the range of ˜20 μm.

[0040]   Preparation of ink composition   Thermosetting fluorescent yellow resin granular material B 5.0   Adhesive resin particle dispersion A 15.0   Ethylene glycol 10.0   Penetrant 0.3   [Product name: Acetinol EH, Kawaken Fine Chemicals Co., Ltd.]   Silicone defoamer 0.1   Preservative (trade name: Proxel XL-2, manufactured by Zeneca) 0.1   Water 69.5   Total 100.0

The above composition was mixed and stirred with a disper until it became homogeneous to obtain an ink composition. The viscosity of the obtained ink composition was 6.1 mPa · s (ELD viscometer, 2
5 ° C.).

Example 3 Preparation of Adhesive Resin Granules The oil phase solution of the adhesive resin granules A of Example 1 was 78 parts butyl acrylate, 52 parts ethyl methacrylate, and 1 part t-butyl peroxypivalate. Reacted in the same manner as in Example 6. However, the rotation speed was 500 rpm and the average particle diameter was adjusted to 4 μm. The solid content of the obtained adhesive resin particles was adjusted to 30% with water to obtain an adhesive resin particle dispersion liquid B. The average particle diameter of the particles in the adhesive resin particle dispersion B is 4.8 μm,
90% by weight of all particles in the range of 2 μm to 10 μm
Was included.

Preparation of thermosetting colored resin granules The same composition as in Example 1 except that 3 parts of the fluorescent yellow dye of Example 1 was replaced with 3 parts of fluorescent red dye (Sumiblast Pink B, basic dye). A thermosetting fluorescent red resin granular material C was obtained by the same method. The average particle size of the particles in the thermosetting fluorescent red resin particles C was 6.5 μm, and the particles were 2 μm.
89% by weight of all particles was contained in the range of m to 10 μm.

[0044]   Preparation of ink composition   Thermosetting fluorescent red resin granular material C 10.0   Adhesive resin particle dispersion B 20.0   Ethylene glycol 10.0   Urea 5.0   Silicone defoamer 0.1   Succinoglycan 0.2   (Organic acid modified heteropolysaccharide, average molecular weight of about 1 to 8 million)   Phosphate ester type surfactant 0.5   [Product name: Prysurf M208B, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.]   Water 54.2   Total 100.0

The above-mentioned composition was mixed and stirred with a disper until it became homogeneous to obtain an ink composition. The obtained ink composition has a viscosity (25 ° C., 100 r as measured by an EMD viscometer).
The viscosity in pm) was 48 mPa · s, and the shear thinning index (n) was 0.364.

Example 4 Preparation of thermosetting colored resin granules Benzoguanamine 1 was placed in a separable flask equipped with a stirrer.
20 parts, p-toluenesulfonamide 30 parts, formaldehyde aqueous solution (37%) 118 parts, sodium carbonate aqueous solution (10%) 0.5 parts were added, and the mixture was stirred at 95 ° C.
The reaction was carried out for 2 hours to obtain a meltable resin of benzoguanamine, p-toluenesulfonamide and formaldehyde.
Then, the meltable resin is added to an aqueous solution prepared by dissolving 6 parts of polyvinyl alcohol (trade name: Kuraray Poval 205, manufactured by Kuraray Co., Ltd.) in 600 parts of water, and stirring is performed at 500 rpm so that the average particle diameter becomes about 5 μm. After that, 5 parts of fluorescent red dye (Sumiblast Pink B, basic dye) was added, and the mixture was further stirred at room temperature for 30 minutes for dyeing. Then, 40 parts of 1N sulfuric acid was added to 40 ° C, 50 ° C, 60 ° C, 70
Stir for 2 hours at each temperature of ℃, 80 ℃, 90 ℃,
A suspension of the cured product was obtained. The cured product is filtered off from the suspension, and 1
After being dried at 00 ° C. and further heat-treated at 150 ° C. for 3 hours using a hot air dryer, a thermosetting fluorescent red resin granular material D was obtained through a 500 mesh wire mesh sieve. The average particle size of the particles in the thermosetting fluorescent red resin particles D was 5.8 μm, and the particles contained 87% by weight of all particles in the range of 2 μm to 10 μm.

[0047]   Preparation of ink composition   Thermosetting fluorescent red resin granules D 10.0   Adhesive resin particle dispersion B 20.0   Ethylene glycol 10.0   Urea 5.0   Silicone defoamer 0.1   Succinoglycan 0.2   (Organic acid modified heteropolysaccharide, average molecular weight of about 1 to 8 million)   Phosphate ester type surfactant 0.5   [Product name: Prysurf M208B, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.]   Water 54.2   Total 100.0

The above composition was mixed and stirred with a disper until it became homogeneous to obtain an ink composition. The obtained ink composition has a viscosity (25 ° C., 100 r as measured by an EMD viscometer).
The viscosity in pm) was 48 mPa · s, and the shear thinning index (n) was 0.365.

Preparation of Sample Marking Pens The ink compositions of Examples 1 and 2 each had a valve mechanism in an aluminum barrel, and a tip formed by binding a fiber bundle provided at the writing tip with a resin. At the time of writing, it was pressed against the paper surface to open the valve, and the ink in the barrel was filled in a marking pen of the type to be used as a sample marking pen.

Preparation of Sample Ballpoint Pens The ink compositions of Examples 3 and 4 were filled in a ballpoint pen in which a stainless steel chip holding a 0.7 mm diameter cemented carbide ball was fitted to one end of a polypropylene barrel. Further, the ink backflow preventive body (silicone grease type) was filled in close contact with the rear end surface of the ink and subjected to a centrifugal treatment, and then filled into a ballpoint pen of a type in which a tail plug was fitted to obtain a sample ballpoint pen.

Erasability Test and Light Scratch Resistance Test Using each of the above sample pens, report paper (manufactured by KOKUYO, product number
116AN), a circle with a diameter of about 2 cm is continuously drawn, and the resulting handwriting is erased [Seed Rubber Industry Co., Ltd.
Manufactured, trade name: STAR Radar], and the difficulty of erasability was determined by rubbing 5 seconds and 1 day after writing. For light scratch resistance, filter paper (No. 2 filter paper made by ADVANTEC) was placed on the handwriting one hour after writing, with the smooth surface facing the handwriting side, and 45.5 from above.
A light scratch resistance was evaluated by sliding the handwriting 10 times with a load of g / square centimeter applied.

The following table shows the test results of the color tone of the handwriting, erasability and light scratch resistance.

[0053]

[Table 1]

The judgment symbols for the results of the erasability and light scratch resistance tests in the table are as follows. Erasability: Very easy to erase. ◯: Can be easily erased. Light scratch resistance ◯: Almost no handwriting is peeled off.

[0055]

INDUSTRIAL APPLICABILITY The present invention has a particle distribution of 2 μm to
An ink composition in which a thermosetting colored resin granule and a sticky resin granule containing a dye in an amount of 20 μm in an amount of 70% by weight or more are dispersed in a medium, and the applied granule penetrates into the paper. Since it has extremely low resistance and satisfies both eraser erasability and light scratch resistance, the handwriting obtained by writing on paper can be easily erased with an eraser, and the handwriting is normal fingers or paper-to-paper It is possible to provide an eraser-erasable water-based ink composition for writing and a writing instrument containing the same, which both satisfy the handwriting retention which is not erased by the rubbing process degree.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C350 GA03 GA04 NA19                 4J039 AD08 AD10 AE02 AE03 AE04                       AE05 AE06 AE08 AE11 BA04                       BA12 BA23 BA32 BA35 BC10                       BC11 BC15 BC35 BC36 BC39                       BC60 BE01 BE02 BE03 BE04                       BE05 BE07 BE12 CA03 EA28                       EA37 EA39 GA27

Claims (10)

[Claims] 1. A thermosetting colored resin granule containing a dye,
It is composed of at least an adhesive resin particle, water, and a water-soluble polar solvent, and the particle distribution of each of the thermosetting colored resin particle and the adhesive resin particle is 70% by weight or more in the range of 2 μm to 20 μm. Erasable water-based ink composition for writing. 2. The eraser-erasable water-based ink composition for writing according to claim 1, wherein the dye is a basic dye. 3. The water-based ink composition for erasing with an eraser according to claim 1, wherein the weight ratio of the dye contained in the thermosetting colored resin granules is 0.1 to 20% by weight. 4. The writing eraser according to claim 1, wherein the thermosetting resin contained in the thermosetting colored resin particles is a guanamine resin and / or a melamine resin. Erasable water-based ink composition. 5. A thermosetting colored resin granule and an adhesive resin granule comprising 5 to 30% by weight of a thermosetting colored resin granule and 0.5 to 15% by weight of an adhesive resin granule. The weight ratio of the body is 100: 2-200.
An eraser-erasable water-based ink composition for writing according to any one of 1. 6. The sticky resin particles are present in a point-adhered state between particles and between particles and the paper surface in a handwriting after drying formed on the paper surface. An eraser-erasable water-based ink composition for writing according to any one of items. 7. A marking pen comprising the writing eraser-erasable water-based ink composition according to any one of claims 1 to 6. 8. An ink composition comprising a shear thinning agent and having a viscosity at 100 rpm of 25 to 160 mPas.
The eraser erasability for ball-point pens according to any one of claims 1 to 6, which is s (value of EMD type viscometer at 25 ° C) and has a shear thinning index of 0.1 to 0.7. Aqueous ink composition. 9. The particle distribution of the thermosetting colored resin particles and the adhesive resin particles contained in the ink composition is from 2 μm to.
The eraser-erasable water-based ink composition for a ballpoint pen according to claim 8, which is contained in an amount of 80% by weight or more in the range of 10 μm. 10. A ballpoint pen comprising the eraser-erasable water-based ink composition for a ballpoint pen according to claim 8 or 9.