JP2003128975A - Photochromic ink composition for marking pen and marking pen including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photochromic ink composition for a marking pen, which is a photochromic ink composition useful for a marking pen equipped with a pen body having a capillary gap and an ink absorbent body, has properties of neither separation nor settling of photochromic microcapsule pigment in the ink absorbent body and excellent ink discharge properties from the ink body and the marking pen including the composition. SOLUTION: This photochromic ink composition for a marking pen comprises a photochromic composition-containing photochromic capsule pigment which is suspended in a mild flocculating state by a mild crosslinking action by a water-soluble polymer flocculant. This marking pen includes the photochromic ink composition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photochromic ink composition for a marking pen and a marking pen incorporating the same. Specifically, a low-viscosity photochromic ink composition applied to a marking pen provided with an ink drawing means having a capillary gap, and a marking provided with a pen body made of a fiber material and an ink storage body to which the ink composition is applied. Regarding the pen.

[0002]

2. Description of the Related Art Heretofore, proposals have been made to use microcapsules containing a photochromic composition as a colorant for a water-based ink for writing instruments (Japanese Patent Laid-Open No. 2-11).
No. 0174, JP-A-8-156479). The above proposal is an attempt to permanently develop the color change function of the photochromic composition by making it difficult to be affected by a gas such as a specific oxygen gas, a light beam, or a vehicle containing various additives in the ink, and It satisfies the sex. However, the ink composition for a writing instrument using the microcapsules generally has a specific gravity of 1 or less, so that the microcapsules are easily separated in an aqueous ink, and when written, the microcapsules do not transfer to the paper surface and the handwriting is thin. Become
Alternatively, there is a risk that the ink flow will be obstructed and the handwriting will be faint, or writing will be impossible. In order to solve the above-mentioned problems, it is necessary to enhance the dispersion stability of the capsule in the ink, and one example is the absorption of ink into a fiber bundle in which a capillary gap is formed between fibers in the barrel of a writing instrument. House the body,
A method of impregnating the ink composition into the ink storage body can be considered, but it is separated in the ink storage body over time and the writing tool is left in a standing state (the pen body side is facing upward, downward, or,
(Sideways) gives a handwriting with a marked difference in shade,
It is not possible to sufficiently solve problems such as clogging in the pen body and making ink outflow impossible.

[0003]

The present applicant further pursues an ink using microcapsules containing a photochromic composition, and further embodies the above proposal,
It is an object of the present invention to provide a photochromic ink composition that further improves ink outflow from a pen body having a capillary gap and provides handwriting with high concentration and excellent durability, and a convenient marking pen that satisfies the practical use using the same. It is what

[0004]

The present invention provides a photochromic microcapsule pigment containing a photochromic composition,
A photochromic ink composition for a marking pen, which contains at least a water-soluble polymer flocculant and water and has an ink viscosity in the range of 2 to 30 mPa · s is required. Further, it is required that the water-soluble polymer flocculant is a nonionic water-soluble polymer compound. Further, a plurality of fibers are arranged in close contact with each other, and a fiber processed body in which a capillary gap is formed between adjacent fibers is used as a pen body, and a fiber bundle body in which a capillary gap is formed between adjacent fibers is used. An ink occlusion body, a rear end of the pen body is assembled to the front end of the ink occlusion body in a connected state, and a marking pen obtained by impregnating the ink occlusion body with a photochromic ink composition for a marking pen is required. .

The photochromic microcapsule pigment is a pigment containing a conventionally known organic photochromic compound and a photochromic composition comprising a nonvolatile high boiling point organic compound or a low melting point organic compound which is liquid or solid at room temperature. As the organic photochromic compound,
Benzopyran compounds such as 6-methoxy-2,2-diphenyl-2H-1-benzopyran, naphthopyran compounds such as 3,3-diphenyl-3H-naphtho [2,1-b] pyran, 1,3,3- Trimethyl-indolino-6 '
-Spiropyran compounds such as nitrobenzospiropyran, 1,3-dihydro-1,3,3-trimethyl-6 '
-(1-Piperidinyl) -spiro [2H-indole-
2,3 '-[3H] naphtho [2,1-b] [1,4] oxazine], 1,3-dihydro-1,3,3,4,5-
Pentamethyl-spiro [2H-indole-2,3'-
[3H] naphtho [2,1-b] [1,4] oxazine], 1- (2,4-dichlorobenzyl) -3,3-dimethyl-5,6-dichlorospiro [indoline-2,
Examples thereof include spirooxazine compounds such as 3 '-[3H] naphtho [2,1-b] [1,4] oxazine].
Examples of the nonvolatile high boiling point organic compound or low melting point organic compound which is liquid or solid at room temperature include hydrocarbons such as aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons and halogenated hydrocarbons, and aliphatic alcohols. Examples thereof include compounds selected from alcohols such as aromatic alcohols, esters, ethers, glycol ethers, ketones, and acid amides. The erasing time can be adjusted by a combination of the non-volatile high-boiling point organic compound or the low-melting point organic compound included together with the organic photochromic compound.

Microencapsulation of the photochromic composition is carried out by interfacial polymerization, interfacial polycondensation, in situ.
Known means such as the u polymerization method and the coacervate method can be applied. The particle size of the microcapsule pigment is 0.5 to 5
The range of μm, preferably 1 to 3 μm satisfies the practicality.

The photochromic microcapsule pigment applied to the present invention preferably has a non-circular cross-sectional shape, particularly a cross-sectional shape having a depression. In the process of passing through the capillary gap, the pigment having the above-described shape has the major axis side (maximum outer diameter side) oriented along the capillary gap and smoothly flows in the writing tip direction. Satisfies the ink outflow characteristics of. In particular, it is excellent in ink outflow from a pen having a large number of fine gaps formed between fibers, allowing the ink to flow out satisfactorily,
Gives a high concentration of handwriting. Here, the non-circular cross-sectional shape of the capsule pigment has an average maximum outer diameter of 0.5 to 5.0 μm.
m range and photochromic composition / wall film =
It is preferable to satisfy the range of 7/1 to 1/1 (weight ratio). The above-mentioned capsule pigment has a decrease in the outflow property from the capillary gap in a system having an average maximum outer diameter of more than 5.0 μm, while the average maximum outer diameter is 0.5 μm.
In the following system, it is difficult to exhibit high-concentration color developability, preferably,
It is preferable that the average value of the maximum outer diameter is in the range of 1 to 4 μm, and the average particle diameter [(maximum outer diameter + minimum outer diameter of the central part) / 2] of the microcapsules is in the range of 1 to 3 μm. When the ratio of the photochromic composition to the wall film is larger than the above range, the thickness of the wall film becomes too thin and the durability is deteriorated. Conversely, when the ratio of the wall film to the photochromic composition is larger than the range. It is unavoidable that the color density and the sharpness at the time of color development are lowered, and preferably the photochromic composition / wall film = 6/1 to 1/1 (weight ratio). In order to obtain a microcapsule pigment having a non-circular cross-sectional shape in the above particle size range, it is effective to apply an interfacial polymerization method or an interfacial polycondensation method in which aggregation and coalescence hardly occur.

The photochromic microcapsule pigment may be added in an amount of 0.5 to 40% by weight, preferably 1 to 20% by weight, based on the total amount of the ink composition. 0.5% by weight
If it is less than 40% by weight, the color density is insufficient, and if it exceeds 40% by weight, the ink outflow is deteriorated and the writing property is impaired. Incidentally, a non-photochromic dye or pigment may be mixed in the ink to make the color change various.

The water-soluble polymer flocculant used in the present invention is such that, due to the water-soluble polymer flocculant, a pigment suspension in a flocculated state due to a loose bridging action between pigment particles separates the pigment in the capillary tube. It is based on the finding that it is difficult to cause, and even when applied to a marking pen having a pen body having a capillary gap and an ink occlusion body having a capillary gap in which fibers are bundled, separation of microcapsules occurs in the capillary gap. This problem is solved by the fact that the writing instrument is left in a neglected state to give a handwriting with a marked difference in shade, and clogging in the pen body makes the ink outflow impossible. A nonionic water-soluble polymer compound is preferably used as the water-soluble polymer flocculant that gives a loose bridging action between the microcapsule pigment particles. Specific examples include polyvinylpyrrolidone, polyethylene oxide, water-soluble polysaccharides and nonionic water-soluble cellulose derivatives. Among these, specific examples of the water-soluble polysaccharides include tragacanth gum, guar gum, pullulan, and cyclodextrin, and specific examples of the nonionic water-soluble cellulose derivative include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose, Hydroxypropyl methylcellulose and the like can be mentioned. In the photochromic water-based ink composition of the present invention, any water-soluble polymer exhibiting a loose bridging action between microcapsule pigment particles can be applied, but among them, the above-mentioned nonionic water-soluble cellulose derivative. Is preferably used. The polymer flocculant, relative to the total amount of the ink composition,
It can be blended in an amount of 0.05 to 20% by weight.

In addition to the above components, various additives can be added. As a moisturizing agent that suppresses drying with a nib, glycerin, propylene glycol, ethylene glycol, diethylene glycol, glycols such as low molecular weight polyethylene glycol and lower alkyl ethers thereof, 2-pyrrolidone, N-vinylpyrrolidone, urea and the like. It can be illustrated. The moisturizer can be added in an amount of 5 to 40% by weight based on the total amount of the ink.

Examples of the binder resin added for adjusting the stickiness of the handwriting and adjusting the viscosity include a resin emulsion, an alkali-soluble resin and a water-soluble resin. Examples of the resin emulsion include polyacrylic acid ester and styrene-acrylic acid. Copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer, methacrylic acid-maleic acid copolymer, ethylene-methacrylic acid copolymer, α-olefin-maleic acid copolymer , Polyester, an aqueous dispersion of polyurethane can be exemplified, as the alkali-soluble resin, styrene-maleic acid copolymer, ethylene-maleic acid copolymer, styrene-acrylic acid copolymer can be exemplified, as the water-soluble resin , Polyvinyl alcohol, polyvinyl butyral, etc. can be exemplified,
One kind or a mixture of two or more kinds can be used. Further, a surfactant, a pH adjusting agent, an antiseptic agent and an antifungal agent can be added. Examples of the pH adjusting agent include inorganic salts such as ammonia, sodium carbonate, sodium phosphate, sodium hydroxide and sodium acetate, and organic basic compounds such as water-soluble amine compounds such as triethanolamine and diethanolamine. Examples of the preservative or antifungal agent include carboxylic acid, 1,2-benzisothiazoline-
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 mentioned.

The ink composition of the present invention has a viscosity at 20 ° C. of 2 to 30 mPa · s, preferably 3 to 15 mPas.
・ Adjusted to the range of s. If it is less than 2 mPa · s, it is substantially difficult to prepare an ink composition having a sufficient photochromic property. If it exceeds 30 mPa · s, the ink outflow from the pen is deteriorated to obtain a desired handwriting density. It will be difficult.

Next, a marking pen incorporating the photochromic ink composition for a marking pen will be described. The marking pen is a fiber bundle in which a large number of fibers are arranged in close contact with each other, and a pen is made of a fiber processed body in which a capillary gap is formed between adjacent fibers, and a fiber bundle in which a capillary gap is formed between adjacent fibers. The body is used as an ink occlusion body, and the rear end of the pen body is assembled to the front end of the ink occlusion body in a connected state, and the ink occlusion body is impregnated with the photochromic aqueous ink composition. The fiber processed body,
A porous member having open pores selected from the conventional general-purpose porosity range of about 30 to 70%, such as a resin processed product of fibers, a fusion-bonded product of heat-fusible fibers, and a felt body. One end is processed into a shape according to the purpose, such as a bullet shape, a rectangular shape, or a chisel shape, and is used as a pen body for practical use. The chisel-shaped pen has versatility in that it can be used for thin writing or thick writing by changing the contact position with the writing surface, and can form a mark with a constant line width. You can form a nice handwriting. The fiber bundle is formed by bundling crimped fibers in the longitudinal direction, and is incorporated into a covering such as a plastic cylinder or a film to adjust the porosity in the range of 40 to 90% to absorb ink. The body is composed. Incidentally, the fiber bundle is processed by resin or heat fusion,
It may be welded with a plasticizer or the like. The marking pen may be a double-headed marking pen in which pen bodies of different shapes are attached to both ends of the ink occlusion body.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION If necessary, other components such as a moisturizer are added to an aqueous medium in which a photochromic microcapsule pigment containing a photochromic composition is dispersed, and a predetermined concentration prepared separately. The photochromic ink composition in a suspension state in which a predetermined amount of the aqueous polymer flocculant solution is gradually added, and the microcapsule pigment is in a bridging flocculation state between pigment particles in the aqueous medium by the polymer flocculant. To prepare. The photochromic ink composition is impregnated into an ink occluding body composed of a fiber bundle and is housed in a shaft cylinder equipped with a fiber processed body as a pen body to form a marking pen for practical use.

[0015]

EXAMPLES Examples will be shown below, but the present invention is not limited to the examples. The parts in the examples are parts by weight.

Example 1 Preparation of photochromic microcapsule pigment Organic photochromic compound [spironaphthoxazoline compound, trade name: PHOTOROME 12,
(Yes) Made by Nippon Chemix] 1.5 parts was added to 50 parts of diisononyl adipate (trade name: Sanso Sizer DINA, manufactured by Shin Nippon Rika Co., Ltd.) to form a uniform solution, and an aromatic isocyanate was used as a wall film material. A solution in which 20 parts of a prepolymer / ethyl acetate solution (prepolymer concentration: 75% by weight) was further added and uniformly dissolved was heated to 70 ° C. 1
It was put into 100 parts of a 5% gelatin aqueous solution while stirring and emulsified into fine droplets. Further, react at 80 ° C for 5 hours,
From the obtained microcapsule pigment dispersion liquid, a photochromic microcapsule pigment (average particle diameter 2.0 μ
m) was isolated and obtained.

Preparation of Photochromic Ink Composition for Marking Pen 20 parts of the above photochromic microcapsule pigment, 5 parts of glycerin, 1 part of antifungal agent [trade name: Proxel XL-2, manufactured by Zeneca Co., Ltd.], silicone type Defoaming agent [Product name: SN
Deformer 381, manufactured by San Nopco Ltd.] 0.1
Parts and 65.9 parts of water and then uniformly dispersed in an aqueous medium, and then hydroxyethyl cellulose [trade name: Cellosize WP-09L, manufactured by Union Carbide Japan Co., Ltd.]
Was added with stirring to an aqueous solution containing 5% by weight to obtain a photochromic ink composition for a marking pen.
When the viscosity of the ink composition is measured, it is 4.8 mPa.
It was s [BL by viscometer manufactured by Tokyo Keiki Co., Ltd.
Applying an adapter, measuring at 60 rpm, measuring temperature 20
° C].

Example 2 Preparation of Photochromic Ink Composition for Marking Pen 5% by weight of hydroxyethyl cellulose used in Example 1
10 parts of an aqueous solution containing 5% by weight of methyl cellulose [trade name: Marporose M-25, manufactured by Matsumoto Yushi Co., Ltd.] instead of 8 parts of an aqueous solution containing 6 parts, and 63.9 parts of water. Similarly, a photochromic ink composition for a marking pen was prepared. When the viscosity of the ink composition was measured, it was 5.8 mPa · s [BL adapter was applied using a B-type viscometer manufactured by Tokyo Keiki Co., Ltd., 6
Measurement at 0 rpm, measurement temperature 20 ° C].

Example 3 Preparation of Photochromic Ink Composition for Marking Pen 5% by weight of hydroxyethyl cellulose used in Example 1
Example 1 except that 14 parts of an aqueous solution containing 5% by weight of hydroxypropyl cellulose [trade name: HPC-L, manufactured by Nippon Soda Co., Ltd.] was used instead of 8 parts of an aqueous solution containing 5%, and water was 59.9 parts. A photochromic ink composition for a marking pen was prepared in the same manner as in. The viscosity of the ink composition was measured and found to be 5.7 mPa · s [using a BL type viscometer manufactured by Tokyo Keiki Co., Ltd.,
Measurement at 60 rpm, measurement temperature 20 ° C].

Example 4 Preparation of Photochromic Ink Composition for Marking Pen 5% by weight of hydroxyethyl cellulose used in Example 1
In place of 8 parts of an aqueous solution containing 5 parts by weight of hydroxypropylmethylcellulose [trade name: Metroze 60SH-50, manufactured by Shin-Etsu Chemical Co., Ltd.], 7 parts of an aqueous solution containing 5% by weight,
A photochromic ink composition for a marking pen was prepared in the same manner as in Example 1 except that 66.9 parts of water was used. When the viscosity of the ink composition is measured, it is 7.0 mP.
It was a ・ s [by a B-type viscometer manufactured by Tokyo Keiki Co., Ltd.
Apply a BL adapter and measure at 60 rpm, measurement temperature 20 ° C].

Preparation of Marking Pen [0021] The photochromic ink composition prepared in Examples 1 to 4 was impregnated into an ink occlusion body in which a polyester sliver was coated with a synthetic resin film, immediately after being uniformly stirred, and then housed in a shaft cylinder. Then, a marking pen was produced by assembling the resin-processed pen body made of polyester fiber attached to the tip of the barrel into a connected state. When written on the paper surface with the marking pen, the ink outflow properties are all appropriate, the handwriting is colorless under normal room light, and when exposed to sunlight, it develops a bluish purple color, and when left indoors again, it becomes 1 It turned colorless within minutes. In addition, when the handwriting is irradiated with a UV lamp [Handy UV Lamp LUV-4, ultraviolet wavelength 365 nm, manufactured by Kyonai Seieido Co., Ltd.] in the room, it develops a blue-violet color, and if the irradiation is stopped and left for one minute, it will reappear again. It became colorless. The change in the appearance of the handwriting could be repeated by light irradiation.

Confirmation of cohesiveness When each of the ink compositions of Examples 1 to 4 was observed with a microscope, it was confirmed that all the microcapsule pigments were in an aggregated state. Further, each of the ink compositions of Examples 1 to 4 was uniformly stirred and then allowed to stand at room temperature for 3 days, and both were separated into a transparent vehicle layer (lower layer) and a layer containing a microcapsule pigment (upper layer). However, it could be easily redispersed by stirring.

Confirmation of Writing Performance over Time of Marking Pens The marking pens filled with the ink compositions of Examples 1 to 4 were erected (upward on the pen body side) at 50 ° C. and room temperature (20 ° C.). After leaving each for 30 days in an inverted state (downward from the pen body), the writing performance was confirmed. In all cases, the ink leakage from the pen body was proper, and the color development of the handwriting when left standing in the upright or inverted state There was no change from the beginning.

Comparative Examples 1 to 4 Ink compositions of Comparative Examples 1 to 4 were prepared by substituting water for the water-soluble polymer flocculants in the ink compositions of Examples 1 to 4, respectively.

Confirmation of cohesiveness When the ink compositions of Comparative Examples 1 to 4 were observed under a microscope, the photochromic microcapsule pigments of any of the compositions were in a dispersed state at the initial stage, and no agglomerated state was confirmed. . When each of the ink compositions was allowed to stand for 3 days, in each of the ink compositions, a part of the microcapsule pigment floated on the ink surface as a solid cake, and the other part was dispersed in the aqueous medium. A marking pen constituted by impregnating an ink occlusion body with the ink composition of Comparative Examples 1 to 4 in the same manner as in Example 1 was used at 50 ° C. and room temperature (20 ° C.).
After standing for 30 days in an upright state and an inverted state under each condition, the writing performance was confirmed, and no writing was possible in any upright state due to clogging of the pen body with the microcapsule pigment, In the inverted state, only the aqueous medium is ejected from the pen, exposing the handwriting to sunlight,
No color was developed when irradiated with a V lamp.

[0026]

EFFECT OF THE INVENTION The photochromic ink composition for a marking pen according to the present invention is a photochromic ink composition in which a water-soluble polymer flocculant is loosely crosslinked to form a liquid in a suspended state of a photochromic microcapsule pigment in a loose flocculation state. In a member having a gap, the suspension state is not broken and is stably retained for a long period of time, and the liquid in that state can be led out from the capillary gap. When applied to a marking pen equipped with a pen body and an ink occlusion body,
It is possible to form a uniform and clear handwriting on the writing surface, which shows a proper ink outflow property regardless of the standing state of the pen, and which contains uniformly dispersed photochromic microcapsule pigments.

Claims (3)

[Claims] 1. A photochromic microcapsule pigment containing a photochromic composition, a water-soluble polymer flocculant, and at least water, and has an ink viscosity of 2 to 30 mPas.
・ Photochromic ink composition for marking pen in the range of s. 2. The photochromic ink composition for a marking pen according to claim 1, wherein the water-soluble polymer flocculant is a nonionic water-soluble polymer compound. 3. A fiber bundle in which a large number of fibers are arranged in close contact with each other, and a fibrous body having a gap between adjacent fibers is used as a pen, and a fiber bundle having a gap between adjacent fibers is formed. The body is an ink occlusion body, and the rear end of the pen body is assembled to the front end of the ink occlusion body in a connected state.
A marking pen obtained by impregnating the ink storage body with the photochromic ink composition for a marking pen according to claim 1 or 2.