JP2006206738A - Oil-based gel ink composition and coating device using the ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil-based gel ink composition suppressed in titanium oxide precipitation and securing fluidity and leveling property after a long term of ≥2 months, and to provide a coating device using the composition. <P>SOLUTION: The oil-based gel ink composition comprising at least titanium oxide, a resin and an organic solvent contains different two kinds or more structural viscosity-imparting agents. The coating device A has a ball-point pen tip 12 at the front end and an ink containing pipe 10 at the rear side, wherein, spring pressure is given to the back side of the front end ball so that the front end ball contacts to the internal boundary of a ball-enveloping part at the chip front end and the oil-based gel ink is filled in the ink container pipe 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an oil-based gel ink composition having shear thinning viscosity, in particular, an oil-based gel ink composition mainly composed of an organic solvent, which is used for writing tools, correction tools, adhesives, cosmetics and the like including sign pens and ballpoint pens. About.

  In general, an ink composition containing titanium oxide has a problem that it settles and separates over time due to its high specific gravity. For this reason, means for using the ink composition after sufficiently re-stirring before use or means for imparting shear thinning viscosity to the ink composition and suppressing sedimentation of titanium oxide have been conventionally employed.

  As means for imparting shear thinning to an ink composition, it has been conventionally known to add a thickener or a gelling agent. These additives have been studied with materials having various chemical structures. However, as compared with materials added to an ink composition containing water as a main component (so-called aqueous ink composition), an ink composition containing an organic solvent as a main component (so-called oil-based ink composition), At present, there are few material types examined.

  Examples of the thickener and gelling agent added to the oil-based ink composition include use of montmorillonite clay mineral (for example, see Patent Document 1), use of fluorophlogopite (for example, see Patent Document 2), dextrin. Use of fatty acid esters (for example, see Patent Document 3), fatty acid amides (for example, see Patent Document 4), use of aluminum 2-ethylhexanoate (for example, see Patent Document 5), and the like are known.

When these materials were added to the target ink composition, the formation of a hard cake due to the precipitation of titanium oxide could be suppressed as much as possible for about 2 months. However, when stored for a long period of two months or more, there is a problem that a sedimentation layer is gradually formed at the bottom of the ink. In addition, the gel structure became stronger as a whole or partly with the standing time, and the fluidity and leveling property of the ink composition were reduced due to the decrease in shear thinning.
It goes without saying that quality maintenance for a period longer than two months is required in consideration of providing products to the market. Accordingly, it is desired to provide an oil-based gel ink composition whose quality can be maintained for a longer period of time.

In addition, a material composed of at least one N-acyl amino acid derivative of N-acyl amino acid amide or N-acyl amino acid ester, which is an additive studied in the present invention, is also an oil gelling agent (for example, This is known as Patent Document 6).
However, as described in this document and the like, the additive comprising these N-acylamino acid derivatives is hardly soluble in an organic solvent, and therefore requires a special method such as coexisting an inorganic metal salt as a solubilizing agent. Become. In addition, these additives have a strong action as an oil coagulant, and form a three-dimensional network in a state where the oil is embraced in each network, so that a gel having poor fluidity may be formed. Are known.

  As an ink composition containing an additive having such characteristics, for example, means for adding 0.5 parts by weight of N-lauroyl-L-glutamic acid-α, γ-di-n-butyramide (for example, Patent Document 7), or means for adding 5 parts by weight of N-lauroyl-L-glutamic acid-α, γ-di-n-butyramide (see, for example, Patent Document 8), and 1-10 parts by weight ( For example, a means for adding a patent document 9) is known.

However, in the ink composition to which the gelling agent was added in an amount of 0.5 parts by weight or less, the fluidity was not significantly lowered due to the small content of the gelling agent, and the writing property was good. There is a problem in that sedimentation of titanium oxide cannot be suppressed for a long period of more than a month, and sedimentation separation occurs with the passage of time.
In addition, in the ink composition to which 5 parts by weight or more of the gelling agent is added, the gel network structure is sufficiently formed due to the large amount of the gelling agent, and the precipitation of titanium oxide is suppressed for a long period of 2 months or more. I was able to do it. However, due to the strength of the gel network structure, the fluidity of the ink composition is slightly poor, and the gel strength further increases with the passage of time. A problem that caused a decrease in the beling ability was recognized.
Furthermore, even in an ink composition to which a gelling agent is appropriately added in the range of 1 to 10 parts by weight, particularly in the range of 1 to 5 parts by weight, oxidation occurs when two or more months have elapsed. Either the sedimentation of titanium occurs or the fluidity and leveling properties of the ink composition decrease due to the increase in gel strength. It was not reached.
Japanese Patent Laid-Open No. 6-264012 (Claims, Examples, etc.) JP-A-7-173417 (Claims, Examples, etc.) JP-A-7-324177 (Claims, Examples, etc.) JP 2001-279183 A (Claims, Examples, etc.) JP 2001-158869 A (Claims, Examples, etc.) JP-A-52-68102 (Claims, Examples, etc.) JP 2000-343875 A (Claims, Examples, etc.) JP 2000-343879 A (Claims, Examples, etc.) JP-A-9-53034 (Claims, Examples, etc.) JP 2002-200190 A (claims, examples, etc.)

  The present invention is to solve this problem in view of the above-described conventional problems, and suppresses the precipitation of titanium oxide and improves the fluidity and leveling properties of the ink composition even for a long period of two months or longer. An object of the present invention is to provide an oil-based gel ink composition and an applicator using the ink composition.

  As a result of intensive studies on the above-described problems of the prior art, the present inventor contains at least two types of specific structural viscosity-imparting agents in an ink composition containing at least titanium oxide, a resin, and an organic solvent. The inventors have found that an objective oil-based gel ink composition and an applicator using the ink composition can be obtained, and have completed the present invention.

（１５） 先端にボールペンのチップと後方にインキ収容管を備え、先端ボールがチップ先端のボール抱持部の内縁に密接するように先端ボールの背面にバネ圧が付与されており、インキ収容管に上記（１）〜（１４）の何れか一つに記載の油性系ゲルインキ組成物が充填され、後端部のインキ端面はインキより比重が小さく且つインキと相溶しないゲル状物で厚みが１ｍｍ以上１０ｍｍ以下に封止されていることを特徴とする塗布具。 That is, the present invention resides in the following (1) to (15).
(1) An oil-based gel ink composition containing at least two different structural viscosity imparting agents in an ink composition containing at least titanium oxide, a resin, and an organic solvent.
(2) The oil-based gel ink composition according to the above (1), wherein two or more different structural viscosity imparting agents are any of the following a) to d).
B) Two or more types of structural viscosity imparting agents composed of organic substances and structural viscosity imparting agents composed of inorganic substances.
B) Two or more types of structural viscosity imparting agents composed of organic substances and structural viscosity imparting agents composed of organic / inorganic composite systems.
C) Two or more types of structural viscosity imparting agents composed of inorganic substances and structural viscosity imparting agents composed of organic / inorganic composite systems. D) Two or more types of structural viscosity imparting agents composed of organic / inorganic composite systems.
(3) The total content of two or more different structural viscosity-imparting agents is 0.5 to 11 parts by weight with respect to the total amount (100 parts by weight) of the ink composition, and the total of the above structural viscosity-imparting agents The oil-based gel ink composition according to (1) or (2), wherein the content of the resin is 1.5 to 11 parts by weight with respect to 1 part by weight of the content.
(4) The oil-based gel ink composition according to (2) or (3), wherein the structural viscosity imparting agent comprising an organic substance has at least one hydrophilic functional group capable of hydrogen bonding in the molecular skeleton.
(5) Any of the above (2) to (4), wherein the basic skeleton of the structural viscosity-imparting agent comprising an organic substance is composed of at least one N-acyl amino acid derivative of N-acyl amino acid amide or N-acyl amino acid ester. The oil-based gel ink composition according to one.
(6) The oil-based gel ink according to any one of the above (2) to (5), wherein the structural viscosity imparting agent comprising an organic substance is N-lauroyl-L-glutamic acid-α, γ-di-n-butyramide. Composition.
(7) The oiliness according to any one of the above (2) to (6), wherein the structural viscosity imparting agent comprising an inorganic substance is at least one selected from amorphous silicon dioxide, natural clay mineral, and synthetic clay mineral. -Based gel ink composition.
(8) The oil-based gel ink composition according to the above (7), wherein the amorphous silicon dioxide is produced by a high-temperature hydrolysis process obtained by hydrolyzing a volatile silane compound as a raw material in an oxyhydrogen flame. object.
(9) The above (7) or (8), wherein the amorphous silicon dioxide has a specific surface area of 100 to 400 m ² / g by BET method, the average primary particle diameter is 6 to 20 nm, or the average particle diameter is 5 μm or less. The oil-based gel ink composition described.
(10) Any one of the above (2) to (9), wherein the organic / inorganic composite structural viscosity imparting agent is made hydrophobic by chemically covering the amorphous silicon dioxide surface with a methyl group. The oil-based gel ink composition described in 1.
(11) The oil-based gel ink composition according to the above (10), wherein the coverage of the methyl group on the amorphous silicon dioxide surface hydrophobized with a methyl group is 60% to 100%.
(12) The oil-based gel ink composition according to any one of (7) to (11), wherein the natural clay mineral and the synthetic clay mineral are in the form of flakes in which long-chain organic substances are bonded to the surface.
(13) The oil-based gel ink composition according to any one of the above (1) to (12), wherein the resin is an acrylic resin and the weight average molecular weight is 10,000 to 200,000.
(14) The acrylic resin is 0.4 to part by weight of 93 to 99% by weight of a (meth) acrylic acid ester represented by the following general formula (I) and a basic nitrogen-containing monomer represented by the following general formula (II). The oil-based gel ink composition according to the above (13), which is an acrylic synthetic resin that is obtained by copolymerization and contained in an amount of less than 2 parts by weight.

(15) A tip of a ballpoint pen and an ink containing tube at the back are provided, and a spring pressure is applied to the back of the tip ball so that the tip ball is in close contact with the inner edge of the ball holding portion at the tip of the tip. Are filled with the oil-based gel ink composition according to any one of the above (1) to (14), and the ink end surface of the rear end portion is a gel-like material having a specific gravity smaller than that of the ink and incompatible with the ink. An applicator characterized by being sealed to 1 mm or more and 10 mm or less.

  According to the present invention, the oil-based gel ink composition and the ink composition that suppress the precipitation of titanium oxide and ensure the fluidity and leveling property of the ink composition even for a long period of two months or more are used. An applicator is provided.

Hereinafter, embodiments of the present invention will be described in detail.
The oil-based gel ink composition of the present invention is characterized in that it contains at least two different structural viscosity imparting agents in an ink composition containing at least titanium oxide, a resin and an organic solvent.

In the present invention, the structural viscosity imparting agent to be used must be two or more different structural viscosity imparting agents, that is, two or more types of structural viscosity imparting agents having different physical properties. The use of the imparting agent cannot exhibit the effects of the present invention. Preferably, a structural viscosity imparting agent composed of anisotropic shaped particles whose primary particle shape is needle-like, rod-like, plate-like or layer-like, and whose aspect ratio, a-axis b-axis ratio, etc. is 10 or more, and spherical particle shape What is the structural viscosity imparting agent consisting of is desirable.
Examples of the two or more different structural viscosity imparting agents include those constituted by any one of the following a) to d).
B) Two or more types of structural viscosity imparting agents composed of organic substances and structural viscosity imparting agents composed of inorganic substances.
B) Two or more types of structural viscosity imparting agents composed of organic substances and structural viscosity imparting agents composed of organic / inorganic composite systems.
C) Two or more types of structural viscosity imparting agents composed of inorganic substances and structural viscosity imparting agents composed of organic / inorganic composite systems. D) Two or more types of structural viscosity imparting agents composed of organic / inorganic composite systems.

  The structural viscosity-imparting agent consisting of these a) to d) imparts shear thinning to the entire ink composition by being incorporated in the ink composition, and titanium oxide even for a long period of 2 months or longer. In addition, the fluidity and leveling property of the ink composition can be secured.

The structural viscosity-imparting agent comprising an organic substance used in the present invention has at least one hydrophilic functional group capable of hydrogen bonding in the molecular skeleton, for example, the basic skeleton is an N-acyl amino acid amide or an N-acyl amino acid ester. And those consisting of at least one N-acylamino acid derivative.
Specific examples of structural viscosity-imparting agents that can be used include N-oleoylglycine-n-octylamide, N-cocoylalanine cyclohexylamide, N-lauroylvaline-n-butyramide, N-cured tallow fatty acid acyl. Leucinamide, N-palmitoyl-ε-aminocaproic acid ethylamide, N-caproylmethionine stearylamide, N-decanoylphenylalanine oleylamide, N-myristoylaspartic acid-α, β-diethanolamide, N-acetylglutamic acid-α, γ - dilauryl ^amide, N α, N ε - dicapryloyl lysine ^{dimethylamide,} N α, N ε - dicapryloyl lysine isostearyl ^ester, N α, N ε - dilauroyl lysine octyl ^ester, N α, N δ - Dicapryloyl ornithine Lauryl ^ester, N α, N δ - distearoyl ornithine oleyl ester, N- myristoyl isoleucine ethylamide, N- decanoyl threonine octyl amide, N- stearoyl serine propyl amide, N- butyryl glutamic acid-.alpha., .gamma. dioctyl amide, N- palmitoyl -β- alanyl-octyl amide, N- lauroyl glutamate-.alpha., .gamma. diethylamide, N- lauroyl -L- glutamic acid-.alpha., .gamma. di -n- ^butylamide, N α, N ε - dilauroyl lysine diethylamide N ^α , N ^δ -didecanoyl ornithine myristyl ester, N-2 ethylhexanoyl aspartic acid α, β-dioctylamide stearoyl ornithine oleyl ester, and the like. In addition to these, stearic acid, 12-hydroxystearic acid, hydrogenated castor oil, semi-cured castor oil, sorbitan monostearate, dextrin palmitate (Leopearl KL, KE, TL manufactured by Chiba Flour Mills), 12-hydroxystearic acid monoglyceride (Sarasco) 121, manufactured by Nisshin Oil Co., Ltd.), N-hydroxyethyl-12-hydroxystearylamide (ITOHWAX J-420, manufactured by Ito Oil Co., Ltd.), N, N′-ethylenebisoleylamide (ITOHWAX J-500, manufactured by Ito Oil Co., Ltd.) ), Fatty acid amide wax (Tarren VA-800, 6200-20, 5200-25, 5400-25, 8900-25, manufactured by Kyoeisha Chemical Co., Ltd.), paraffin wax, 12-hydroxyaluminum stearate (Rick Soap RC, Ito Oil Co., Ltd.) ), At least one aluminum stearate (aluminum stearate # 900) (each alone or in combination, the same applies hereinafter) and the like.
In the structural viscosity imparting agent comprising these organic substances, N-lauroyl-L-glutamic acid-α, γ-di-n-butylamide is preferably used from the viewpoint of network structure formation and swelling gelation.

Examples of the structural viscosity imparting agent made of an inorganic material used in the present invention include at least one selected from amorphous silicon dioxide, natural clay mineral, and synthetic clay mineral.
Examples of amorphous silicon dioxide that can be used include those produced by a high-temperature hydrolysis process obtained by hydrolyzing a volatile silane compound as a raw material in an oxyhydrogen flame. Specifically, AEROSIL130 200, 200V, 200CF, 200FAD, 300, 300CF, 380, TT600, MOX170 including aluminum oxide, COK84 (above, Nippon Aerosil Co., Ltd.), P-526, Examples thereof include at least one of P801, P526N, P801N, NP-8, P802, and P-73 (manufactured by Mizusawa Chemical Industry Co., Ltd.).
These amorphous silicon dioxides have a specific surface area of 100 to 400 m ² / g according to the BET method and an average primary particle diameter of 6 to 20 nm or an average particle diameter of 5 μm or less from the viewpoint of network structure formation. Some are preferred. As those having these characteristics, the AEROSIL 200 (specific surface area: 200 m ² / g, average primary particle diameter: 12 nm), the AEROSIL 300 (specific surface area: 300 m ² / g, average primary particle diameter: 7 nm), the P -801 (specific surface area: 140 m ² / g, average primary particle diameter: 2.8 nm). The average particle size was measured by a Coulter counter method.

Examples of natural clay minerals and synthetic clay minerals that can be used include clay minerals having a natural or synthetic thin layer structure, such as smectite, bentonite, laponite, mica, and aluminum silicate. At least one of the above can be used.
Preferably, from the viewpoint of dispersion stability, at least one selected from smectite, bentonite, and laponite is desirable.

The organic / inorganic composite structural viscosity imparting agent used in the present invention includes a dimethylsilyl group on the surface by reacting silanol groups present on the surface of silicon dioxide produced by a high-temperature flame hydrolysis method with silanes and silazanes. And AEROSIL R972, R972S, R972V, R972CF, R974, R974S, R976, R976S, R9765, R202, R805, and the like. , R812, R812S (manufactured by Nippon Aerosil Co., Ltd.).
In these organic / inorganic structural viscosity-imparting agents, the above-mentioned amorphous silicon dioxide surface is chemically coated with a methyl group (dimethylsilyl group or trimethylsilyl group, the same shall apply hereinafter) to make it hydrophobic. It is excellent in the affinity with organic solvents such as, and more preferably, the coverage of methyl group (dimethylsilyl group or trimethylsilyl group) on the amorphous silicon dioxide surface hydrophobized with methyl group However, what is 60 to 100% is desirable. Examples of those having this characteristic include the above-mentioned AEROSILR 974 (coverage: 70%), the above-mentioned AEROSILR 9765 (coverage 80%), and the like.

In addition, as the organic / inorganic composite structural viscosity imparting agent to be used, the above-mentioned clay mineral surface is in the form of flakes in which long-chain organic substances are bonded, or the layer between the layered clay minerals is an organic quaternary ammonium salt. Provided with cation exchange capacity by ion exchange, or organically treated with organic monomers or oligomers having various reactive functional groups such as silane coupling agents, titanium coupling agents, aluminum chelating agents, metal alkoxides, etc. Is mentioned.
As structural viscosity imparting agents comprising these organic and inorganic substances, organic bentonite, specifically, BENTONE14, BENTONE27, BENTONE34, BENTONE38, BENTONESA-38, BENTONEGel OMS, M-P-A MS, M-P-A X , M-P-A 60MS, M-P-A 60X, M-P-A 60T, M-P-A 1078X, M-P-A 2000X, M-P-A 2000T, THIXCIN R, THIXCIN GR, THIXAROL ST, THIXATROL GST, RHEOX-1, RHEOX-53MS, RHEOX-53X, POST-4, THIXSEAL 1084, BENTONE SD-1 (above, manufactured by NLC Chemicals), Sven, Sven WX, Arganite T, S Ben N-400, Esben NZ (manufactured by Hayashi Kasei Co., Ltd.) and the like. Also, Somasifu ME-100 (synthetic mica, manufactured by Coop Chemical Co.), Laponite XLG (synthetic laponite, manufactured by Hojun Co.), Optigel WM (hydrophilic synthetic smectite, manufactured by Sud Chemie), Bengel W-100 (organic modified purified bentonite, Hojun Co., Ltd.), SWN, SAN, STN, SEN, SPN (Smectite, manufactured by Corp Chemical Co.), bentonite (manufactured by Toyoshun Mining Co., Ltd.), thixogel (manufactured by Zud Chemie), and the like.

  These structural viscosity imparting agents use two or more types of structural viscosity imparting agents, specifically, two or more types of organic matter structural viscosity imparting agent and inorganic structural viscosity imparting agent, organic matter structural viscosity imparting agent and organic Two or more types of inorganic composite structural viscosity imparting agents, two or more types of inorganic structural viscosity imparting agents combined with organic / inorganic composite structural viscosity imparting agents, two or more types of organic / inorganic composite structural viscosity imparting agents By using it, the effects of the present invention will be exhibited, and the effects of the present invention will not be exhibited in forms other than those described above, for example, the use of one type of structural viscosity imparting agent.

In the present invention, the total content of these structural viscosity-imparting agents not only ensures a concentration for imparting shear thinning to the ink, but also suppresses titanium oxide sedimentation as much as possible over a long period of two months or more. In addition, in order to ensure the fluidity and leveling properties of the ink composition, the necessary amount must be ensured.
The specific content is preferably selected from the range of 0.5 to 11 parts by weight, more preferably 1 to 8 parts by weight with respect to the total amount of the ink composition (100 parts by weight).
When the content is less than 0.5 parts by weight, no significant decrease in fluidity was observed due to the low content of the gelling agent, and the writing characteristics were good. The sedimentation cannot be suppressed, and there is a problem that sedimentation separation occurs with the passage of time. On the other hand, in the ink composition containing more than 11 parts by weight, the gel network structure is sufficiently formed due to the large amount of the gelling agent, and the precipitation of titanium oxide is suppressed for a long period of 2 months or more. I was able to. However, due to the strength of the gel network structure, the fluidity of the ink composition is slightly poor, and the gel strength is further increased with the passage of time. There was a problem that deterioration of the belling property occurred.

  More preferably, the content ratio of two or more kinds of structural viscosity-imparting agents needs to be set as appropriate from the viewpoint of easy destruction of the network structure of the gel. In the case of the viscosity imparting agent (B), (A) / (B) is 0.1 to 10, and the organic structural viscosity imparting agent (A) and the organic / inorganic composite structural viscosity imparting agent (C). In the case of (A) / (C) being 0.05 to 20, and in the case of the inorganic structural viscosity imparting agent (B) and the organic / inorganic composite structural viscosity imparting agent (D), (B) / ( It is desirable that D) be 0.05 to 1.

As resin used for this invention, at least 1 sort (s), such as an acrylic resin, an alkyd resin, an alkylphenol resin, a polyester resin, a vinyl acetate acrylic resin, can be used, for example.
Preferably, an acrylic synthetic resin is desirable, and the resin is a homopolymer of (meth) acrylic acid ester, a copolymer of two or more types of (meth) acrylic acid esters, or one or more types of (meth) acrylic acid esters. And styrene copolymers are desirable.

このようなアクリル系合成樹脂としては、例えば、ＬＰ−１８９（メチルシクロへキサンアクリル系合成樹脂４０％溶液、重量平均分子量約１０万、藤倉化成社製）などが挙げられる。 Further, preferred resins include 93 to 99 parts by weight of (meth) acrylic acid ester represented by the following general formula (I) and 0.4 parts by weight of a basic nitrogen-containing monomer represented by the following general formula (II). As described above, an acrylic synthetic resin obtained by copolymerization containing less than 2% by weight is desirable.

Examples of such an acrylic synthetic resin include LP-189 (methylcyclohexane acrylic synthetic resin 40% solution, weight average molecular weight of about 100,000, manufactured by Fujikura Kasei Co., Ltd.).

  As said (meth) acrylic acid ester, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, n-butyl (meth) acrylate, 2 -Methacrylates such as ethylhexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, citearyl (meth) acrylate, cyclohexyl (meth) acrylate, and acrylates.

  The (meth) acrylic acid ester represented by the general formula (I) is required to be contained in an amount of 93 to 99 parts by weight as a copolymer component of the acrylic resin. There is a possibility that the solubility in a kind will deteriorate and the writing line becomes brittle. On the other hand, when it exceeds 99 parts by weight, the dispersion stability for pigments such as titanium oxide is adversely affected.

Further, as the basic nitrogen-containing monomer represented by the general formula (II), N, N-dimethylaminoethyl (meth) acrylate, N, N dimethylethylaminoethyl (meth) acrylate, or the like is used.
The basic nitrogen-containing monomer represented by the above formula (II) must be contained in a range of 0.4 parts by weight or more and less than 2.0 parts by weight as a copolymer component of the acrylic resin. When the amount is less than parts by weight, the amount of the resin adsorbed to the titanium oxide pigment decreases, and the dispersion stability particularly tends to deteriorate for a long period of time. On the other hand, if it is 2.0 parts by weight or more, the solubility of the acrylic resin itself in an organic solvent tends to be poor, and the acrylic resin varnish itself is liable to cause phase separation during storage. Become. As a result, it is easy to separate the resin and the solvent over time, resulting in poor storage stability due to poor pigment dispersion (increased viscosity, pigment sedimentation phenomenon), poor writing lines (drawing lines, cracks in drawing lines), etc. This is likely to occur, and there is a possibility that there will be a considerable problem for the purpose of ensuring the fluidity and leveling properties of the ink composition, as well as suppressing the precipitation of titanium oxide by the gel structure. This is because the basic nitrogen-containing monomer is originally a strongly hydrophilic monomer, and inevitably the solubility of the acrylic resin itself in an organic solvent deteriorates as the monomer content increases. Inferred.

In the acrylic synthetic resin preferably used in the oil-based gel ink composition of the present invention, if necessary, less than 5 parts by weight of a styrene monomer may be mixed as a copolymer component. By copolymerizing this styrene monomer, the surface layer of the writing line can be made denser and a flexible line can be obtained. However, if the amount is 5 parts by weight or more, the solubility in an organic solvent may be deteriorated, and the writing line may be brittle.

In the present invention, the resin used is dissolved in an organic solvent and has a performance as a dispersion resin for titanium oxide and other fillers to be used as appropriate, and the amount used is solid relative to the total amount of the ink composition. In terms of minutes, it is 0.9 parts by weight or more, preferably 9 to 22 parts by weight.
When the resin content is less than 0.9 parts by weight, poor dispersion of the pigment occurs or the writing line becomes very brittle. On the other hand, if it exceeds 22 parts by weight, tackiness will be manifested in the drawn paint film, which is not preferred.

In the present invention, preferably used acrylic resins and the like are compatible with, for example, a structural viscosity-imparting agent composed of at least one N-acyl amino acid derivative of N-acyl amino acid amide or N-acyl amino acid ester, A three-dimensional network structure is formed. The amount of the resin used is preferably 1.5 to 11 parts by weight, more preferably 3 to 9.5 parts by weight with respect to 1 part by weight of the structural viscosity-imparting agent in the composition. It is desirable to use parts by weight.
When this amount is less than 1.5 parts by weight, a network structure in which the amount of the additive is prioritized is formed, so that the action specific to the oil coagulant acts strongly and a gel having poor fluidity is formed. On the other hand, when the amount exceeds 11 parts by weight, the resin component is dominant in the formed three-dimensional network structure, and the fluidity of the ink composition is maintained, but the strength of the gel structure in a stationary state is reduced, The function of suppressing the sedimentation of the pigment, which is the original purpose, cannot be exhibited with the passage of time.

The manufacturing method of the above-mentioned acrylic resin used in the present invention can be manufactured by a conventionally known solution polymerization method. Further, it should be noted that the acrylic resin used in the present invention has a weight average molecular weight of 10,000 to 200,000, and at least one N-acyl amino acid derivative of N-acyl amino acid amide or N-acyl amino acid ester. The content of the additive consisting of 1 to 11 parts by weight, preferably 1.5 to 11 parts by weight, preferably 3 to 9.5 parts by weight. Due to the phenomenon that a part of the dispersion medium contained in the gap of the gel structure is detached by shrinking in the process of aging of the structure, the problem of generating a translucent or transparent liquid from the gel ink composition) Can be greatly reduced.
The acrylic resin has a molecular weight of less than 10,000, and an acrylic resin content of 1 part by weight of an additive comprising at least one N-acylamino acid derivative of N-acylamino acid amide or N-acylamino acid ester. When the amount of the system resin is less than 1.5 parts by weight, the shrinkage of the gel structure accompanying the aging of the gel structure cannot be suppressed. On the other hand, the molecular weight of the acrylic resin is 200,000 or more, and the content of the additive consisting of at least one N-acylamino acid derivative of N-acylamino acid amide or N-acylamino acid ester is 1 part by weight, If the amount of the acrylic resin exceeds 11 parts by weight, it is possible to suppress the shrinkage of the gel structure accompanying the aging of the gel structure, but the physical steric hindrance of the acrylic resin acts on the gel structure. Reduce the overall strength. For this reason, the sedimentation of the pigment cannot be suppressed, and as a result, a supernatant liquid is generated, and a translucent or transparent liquid is generated in appearance as in the case of separation.

  Examples of the titanium oxide used in the present invention include rutile type or anatase type titanium dioxide. Commercially available titanium dioxides that can be used include TITANIX JR-301, JR-701, JR-600, JR-801 (above, manufactured by Teica), Taipure R-900, R-931, R -960 (above, manufactured by DuPont), TITON SR-1, KA-10, KA-20 (above, manufactured by Sakai Chemical Industry), Kronos KR-310, KR-380, KR-380N, KR-460 (above, manufactured by Titanium Industry Co., Ltd.), R-780, R-820, CR-50, CR-93 (above, made by Ishihara Sangyo Co., Ltd.) can be mentioned.

The content of these titanium dioxides is in the range of 5 to 60 parts by weight, preferably 10 to 50 parts by weight, based on the intended use of the oil-based gel ink composition, with respect to the ink composition dye.
When the content of titanium oxide is less than 5 parts by weight, the titanium dioxide is not fully concealed. On the other hand, if the amount exceeds 60 parts by weight, the strength of the gel structure must be increased in order to make it difficult to precipitate all the titanium oxide, and the fluidity as ink cannot be ensured. Also, there is no limitation on the particle size of titanium dioxide that can be used.

  The organic solvent used for this invention will not be limited at all, if it is normally used for a writing instrument, a correction tool, an adhesive agent, a cosmetics, etc. Specific examples of the organic solvent include nonpolar aliphatic hydrocarbons and naphthenic hydrocarbons such as n-hexane, isohexane, n-heptane, n-octane, isooctane, cyclohexane, methylcyclohexane, and ethylcyclohexane. And at least one selected from aromatic hydrocarbons such as toluene and xylene, and halogenated hydrocarbons such as 1,2,1-trichloroethane and tetrachloroethane.

Preferably, from the viewpoints of drying time and viscosity adjustment of a coating film having good hiding properties, the vapor pressure at 20 ° C. is 1 mmHg or more, and the solubility parameter δ is low polarity and relatively volatile corresponding to 10 or less. Specific examples include high organic solvents, and specifically, at least one selected from n-hexane, isohexane, n-heptane, n-octane, isooctane, cyclohexane, methylcyclohexane, ethylcyclohexane, toluene, and xylene. Species are mentioned.
The content of these organic solvents is 20 to 80 parts by weight, preferably 35 to 60 parts by weight with respect to the total amount of the ink composition. However, depending on the type of organic solvent, it may be difficult to dissolve an additive or other resin composed of at least one N-acylamino acid derivative of N-acylamino acid amide or N-acylamino acid ester, and easily There is a possibility that it cannot be used in a gel ink composition. However, the additive and other resins used in the present invention can be dissolved by heating. If the melting temperature of the additive or resin is higher than the boiling point of the organic solvent to be used, the boiling point of the organic solvent is temporarily increased to the melting temperature of the additive or resin under a pressure environment. Can be dissolved.

In the present invention, the titanium oxide, the resin, the organic solvent, and two or more different structural viscosity-imparting agents are contained. A dispersant for dispersion stability such as a colorant and a titanium oxide used as a masking agent, and various other additives can be appropriately contained as required.
In the present invention, the viscosity of the oil-based gel-based ink composition can be adjusted to be 250 mPa · s or less at a shear rate of 400 s ⁻¹ at 25 ° C. and 3000 mPa · s or less at a shear rate of 5 s ⁻¹ . preferable.

The oil-based gel ink composition of the present invention configured as described above is one that suppresses the precipitation of titanium oxide and ensures the fluidity and leveling property of the ink composition even for a long period of 2 months or more. Will be.
In particular, as one type of structural viscosity imparting agent, the basic skeleton is an organic structural viscosity imparting agent from at least one N-acyl amino acid derivative of N-acyl amino acid amide or N-acyl amino acid ester, and other structural viscosities. When two or more kinds of imparting agents (inorganic matter structural viscosity imparting agent, organic / inorganic composite structural viscosity imparting agent) are used, the total amount of the ink composition is 0.5 to 11 parts by weight. In addition, the content of the acrylic resin is 1.5 to 11 parts by weight and the weight average molecular weight is 10000 to 200000 with respect to 1 part by weight of the structural viscosity imparting agent. It is possible to provide an oil-based gel ink composition that suppresses the precipitation of titanium oxide and further secures the fluidity and leveling property of the ink composition even in the above-mentioned long period of time. Also significantly inhibited the syneresis phenomena in the composition became possible.

  The oil-based gel-based ink composition of the present invention can be suitably used for fluid applicators such as writing tools, correction tools, adhesive applicators, and cosmetic tools including sign pens and ballpoint pens. It is accommodated in a storage tube of an applicator provided with a material outflow suppression mechanism. In addition, you may accommodate the end part movable stopper (backflow prevention body) which is not compatible with this fluid composition in the contact state at the end of the fluid composition accommodated in the accommodation tube of the applicator. Components other than these, which are used in ordinary ink compositions, can be arbitrarily used depending on the application.

  As described above, the applicator of the present invention includes a tip of a ball pen at the tip and an ink storage tube at the rear, and the tip end is in close contact with the inner edge of the ball holding portion at the tip end. A spring pressure is applied to the back surface of the ball, and the ink containing tube is filled with the oil-based gel ink composition having the above-described configuration. For example, a knock type ballpoint pen type fluid applicator provided with a pressure pumping mechanism described in Japanese Patent Application Laid-Open No. 2000-335173 by the applicant of the present application, and a main body having a pressure mechanism as shown in FIGS. And a pressure type knock type fluid applicator (correcting pen) A which can be freely attached to and detached from the part.

  The configuration and the like of the pressure type knock type fluid applicator A shown in FIG. 1 and FIG. 2 will be briefly described. A ball-point pen tip (example of application unit) 12 is provided at the tip, and an ink containing tube (refill) 10 is provided at the rear. The refill unit 14 is loaded into the shaft main body 18 in a state in which the refill unit 14 is ejected rearward by the first spring 16, and the ballpoint pen tip 12 of the refill unit 14 is placed on the rear end side of the shaft main body 18. A fluid applicator that can be projected and retracted from the tip opening 18a in conjunction with the push-out operation and push-out release operation of the provided knock mechanism 20, and the rear portion 10r in the fluid housing tube 10 of the refill unit 14 is opened, In the shaft body 18, a pressurizing mechanism 22 for increasing the pressure inside the refill 10 is provided between the rear portion 10 r and the knock mechanism 20. And a second spring 28 that repels the seal portion 24 and the cylindrical portion 26 in a direction to separate them, and after the push-out operation of the knock mechanism 20 is completed, the shaft main body 18 is provided. When the refill unit 14 is retracted by pressing the tip of the ball-point pen tip 12 protruding from the pressure mechanism 22, the seal portion 24 is retracted and the cylinder portion 26 is relatively advanced so that the internal pressure chamber 40 is moved forward. The internal air is compressed, the check valve 29 is opened by the compressed internal air, and the inside of the refill 10 is pressurized through the seal portion 24. The pressurization mechanism 22 releases the pressurization state in the refill 10 when the pen point of the ballpoint pen tip 12 of the refill unit 14 is immersed in the shaft body 18 when the knock mechanism 20 is pushed out. . Further, the refill unit 14 includes an oil-based gel ink composition (correction liquid) 30, a refill 10 having a trailing end filled with a follower 32 that follows the oil-based gel ink composition 30, and a ballpoint pen press-fitted in front of the refill 10. The ball that is configured to include the tip 12 and is loosely fitted in the tip of the ballpoint pen tip 12 is urged toward the front by a spring (spring pressure) 11b through the push rod 11a, and the back pressure is applied. The tip of the ball-point pen tip 12 is closed when not applied. The rear portion of the oil-based gel ink composition 30 in the refill 10 is filled with a follower 32 for the purpose of preventing volatilization of the solvent content of the oil-based gel ink composition 30.

In this fluid applicator, when the flow rate of the oil-based gel ink composition is necessary, the refill 10 is further pushed into the pressurizing mechanism by pressing the tip of the application part 12 protruding from the shaft body 18 against the application surface. A larger pressing force can be applied in the refill 10. Thus, since it can pressurize only at the time of use, the leakage of the oil-based gel ink composition (correction liquid) when not in use can be prevented. Furthermore, the ink containing tube (refill) 10 itself is made of a single layer or a composite layer of nylon resin (polyamide), EVOH, or the like having visibility, so that it has excellent visibility and clear drainability, and is particularly advantageous. Since parts for pressure are not necessary, the cost of refilling can be kept low, and the running cost due to refilling replacement can be reduced. The shaft body 18 also has a visibility resin such as polypropylene (PP), polyethylene (PE), cyclic polyolefin, polymethylpentene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polycarbonate. If (PC) or the like is used, the remaining amount of the oil-based gel ink composition 30 filled in the ink containing tube 14 having visibility can be easily visually confirmed.
Further, the follower 32 that follows is a gel-like material having a specific gravity smaller than that of the ink and incompatible with the ink, and preferably has a thickness of 1 mm or more and 10 mm or less.

  In the applicator of the present invention constructed as described above, a tip of a ball-point pen and an ink storage tube are provided at the back, so that the tip ball is in close contact with the inner edge of the ball holding portion at the tip of the tip. Since the spring pressure is applied to the back surface of the tip ball and the oil-based gel ink composition having the above-described configuration is filled in the ink containing tube, the oil-based gel ink composition filled in the ink containing tube is About 3 months or longer, sedimentation of titanium oxide in the ink composition is suppressed and fluidity and leveling of the ink composition can be secured. As a result, a fluid applicator that can be significantly suppressed is obtained.

  Next, the oil-based gel ink composition of the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition, all the compounding quantity of the Example was shown by the weight part.

[Examples 1 to 9 and Comparative Examples 1 to 4]
The blending compositions shown in Tables 1 and 2 below were mixed and dispersed for 6 hours in a bead mill or heated and mixed and dispersed in a pressure cooker (autoclave) with a stirrer to obtain each oil-based gel ink composition.
About the obtained oil-based gel ink composition of an Example and a comparative example, the following evaluation method evaluated the presence or absence of formation of a sedimentation layer, ink fluidity | liquidity, leveling property, and release property.
These results are shown in Tables 1 and 2 below.

(Evaluation method of sedimentation layer formation)
Fill a container with an inner diameter of 30 mm with a height of 50 mm, leave it at room temperature of 25 ° C. for 2 months, and use a disk adapter with a diameter of 20 mm with a rheometer NRM-2010J-CW (manufactured by Fudo Kogyo Co., Ltd.). The ink load was measured at a gantry speed (speed at which the disk pushes the ink) at 2 cm / min. In addition, the confirmation of whether a sedimentation layer was formed was obtained by calculating the rate of change in excess according to the following formula and evaluating it according to the following evaluation criteria.
Overload change rate (%) = [(overload 2−overload 1) ÷ overload 2] × 100
Overload 1: Overload at a height of 45 mm from the bottom of the ink Overload 2: Overload at a height of 5 mm from the bottom of the ink Evaluation criteria:
A: No formation of sedimentation layer (overweight change rate is less than 1%)
○: Almost no sedimentation layer is formed (overweight change rate is 1% or more and less than 5%)
Δ: Slightly formed sedimentation layer (overweight change rate is 5% or more and less than 10%)
×: Sedimentation layer is formed (overweight change rate is 10% or more)

(Evaluation method of ink fluidity)
A tip of a ball-point pen and an ink storage tube are provided at the tip, and spring pressure is applied to the back of the tip ball so that the tip ball (ball diameter 1.0 mm) is in close contact with the inner edge of the ball holding portion at the tip of the tip. Ink was filled in a container (Mitsubishi Pencil Co., Ltd., CLB-200EW, conforming to FIGS. 1 and 2), and the amount of ink spilled when the tip end was opened for 10 seconds with knocking applied was measured. It was evaluated with.
Evaluation criteria:
A: Large fluidity (flow rate> 25 mg / 10s)
○: Good fluidity (25 mg / 10 s ≧ flow rate> 20 mg / 10 s)
Δ: Poor fluidity (20 mg / 10 s ≧ flow rate> 10 mg / 10 s)
×: No fluidity (10 mg / 10 s ≧ outflow amount)

(Leveling evaluation method)
Using the applicator used in the ink fluidity evaluation method, the inside of a 3.0 cm square was filled and evaluated according to the following evaluation criteria.
Evaluation criteria:
A: High leveling property (area of smooth portion in square is 90 to 100%)
○: Leveling property is good (the area of the smooth part in the square is 80 to 90%)
Δ: Leveling property is poor (the area of the smooth part in the square is 50 to 80%)
X: No leveling (the area of the smooth part in the square is 0 to 50%)

(Evaluation method of syneresis)
An apparatus-dedicated container having an inner diameter of 16 mm and a height of 145 mm was filled with ink to a height of 80 mm, and left in a sealed state using a dedicated lid with high sealing properties. And using the dispersion | distribution solution evaluation apparatus TURBISCAN-MA2000 (made by Formal Action Co., Ltd.), the range in which the permeation | transmission intensity | strength becomes 50% or more in the ink upper part was measured, and the following evaluation criteria evaluated. The measured distance was set to zero as the reference value on the top surface of the ink (height 80 mm from the bottom of the container).
Evaluation criteria:
A: No separation (measurement distance is 0 to 2 mm)
○: Almost no separation (measurement distance is 2 to 4 mm)
Δ: There is some separation (measurement distance is 4-10mm)
×: There is a separation (measurement distance is 10 mm or more)

* 1 to * 7 in Table 1 are as follows.
* 1: Chronos KR-380N (manufactured by Titanium Industry Co., Ltd.)
* 2: LP-189 (40% MCH acrylic synthetic resin solution, manufactured by Fujikura Kasei Co., Ltd.)
* 3: Methylcyclohexane * 4: GP-1 (Organic structure viscosity-imparting agent, N-lauroyl-L-glutamic acid-α, γ-di-n-butyramide, property: needle shape, manufactured by Ajinomoto Co., Inc.)
* 5: P-801 (inorganic structural viscosity imparting agent, amorphous silicon dioxide, property: spherical, manufactured by Mizusawa Chemical Industry Co., Ltd.)
* 6: R976S (organic / inorganic composite structural viscosity imparting agent, amorphous silicon dioxide with 80% surface coating with methyl group, property: spherical, manufactured by Nippon Aerosil Co., Ltd.)
* 7: BENTON 38 (organic / inorganic composite structural viscosity imparting agent, organic clay, properties: flake, manufactured by NL Chemicals)

  As is clear from the results of Tables 1 and 2, Examples 1 to 9 that are within the scope of the present invention are not formed with a sedimented layer as compared with Comparative Examples 1 to 4 that are outside the scope of the present invention. It was found that the ink fluidity and leveling properties were excellent and there was no separation.

It is a partial longitudinal cross-sectional view which shows an example of the applicator of this invention. (A) is the fragmentary longitudinal cross-sectional view of the ink storage tube of FIG. 1, (b) is the fragmentary longitudinal cross-sectional view which shows the principal part of a nib.

Explanation of symbols

A Applicator 10 Ink receiving tube 12 Ballpoint pen tip 14 Refill unit

Claims (15)

  An oil-based gel ink composition comprising at least two different structural viscosity imparting agents in an ink composition containing at least titanium oxide, a resin, and an organic solvent. The oil-based gel ink composition according to claim 1, wherein the two or more different structural viscosity imparting agents are any of the following (a) to (d).
B) Two or more types of structural viscosity imparting agents composed of organic substances and structural viscosity imparting agents composed of inorganic substances.
B) Two or more types of structural viscosity imparting agents composed of organic substances and structural viscosity imparting agents composed of organic / inorganic composite systems.
C) Two or more types of structural viscosity imparting agents composed of inorganic substances and structural viscosity imparting agents composed of organic / inorganic composite systems. D) Two or more types of structural viscosity imparting agents composed of organic / inorganic composite systems.   The total content of two or more different structural viscosity-imparting agents is 0.5 to 11 parts by weight relative to the total amount (100 parts by weight) of the ink composition, and the total content 1 of the structural viscosity-imparting agent is 1 The oil-based gel ink composition according to claim 1 or 2, wherein the content of the resin is 1.5 to 11 parts by weight with respect to parts by weight.   The oil-based gel ink composition according to claim 2 or 3, wherein the structural viscosity imparting agent comprising an organic substance has at least one hydrophilic functional group capable of hydrogen bonding in the molecular skeleton.   The oily substance according to any one of claims 2 to 4, wherein the basic skeleton of the structural viscosity-imparting agent comprising an organic substance is composed of at least one N-acyl amino acid derivative of N-acyl amino acid amide or N-acyl amino acid ester. -Based gel ink composition.   The oil-based gel ink composition according to any one of claims 2 to 5, wherein the structural viscosity imparting agent comprising an organic substance is N-lauroyl-L-glutamic acid-α, γ-di-n-butyramide.   The oil-based gel ink composition according to any one of claims 2 to 6, wherein the structural viscosity imparting agent comprising an inorganic substance is at least one selected from amorphous silicon dioxide, natural clay mineral, and synthetic clay mineral.   The oil-based gel ink composition according to claim 7, wherein the amorphous silicon dioxide is produced by a high-temperature hydrolysis process obtained by hydrolyzing a volatile silane compound as a raw material in an oxyhydrogen flame. The oil-based gel ink composition according to claim 7 or 8, wherein the amorphous silicon dioxide has a specific surface area of 100 to 400 m ² / g by BET method, an average primary particle diameter of 6 to 20 nm, or an average particle diameter of 5 µm or less. object.   10. The oily system according to any one of claims 2 to 9, wherein the organic / inorganic composite structural viscosity imparting agent is obtained by hydrophobically covering the amorphous silicon dioxide surface with a methyl group group. Gel ink composition.   The oil-based gel ink composition according to claim 10, wherein the coverage of methyl group on the surface of amorphous silicon dioxide hydrophobized with methyl group is 60% to 100%.   The oil-based gel ink composition according to any one of claims 7 to 11, wherein the natural clay mineral and the synthetic clay mineral are in the form of flakes in which long-chain organic substances are bonded to the surface.   The oil-based gel ink composition according to any one of claims 1 to 12, wherein the resin is an acrylic resin and has a weight average molecular weight of 10,000 to 200,000. Acrylic resin contains at least 0.4 parts by weight of 93 to 99% by weight of (meth) acrylic acid ester represented by the following general formula (I) and a basic nitrogen-containing monomer represented by the following general formula (II): The oil-based gel ink composition according to claim 13, which is an acrylic synthetic resin which is contained in a range of less than parts by weight and obtained by copolymerization.

  A tip of a ballpoint pen and an ink storage tube at the back are provided, and spring pressure is applied to the back surface of the tip ball so that the tip ball is in close contact with the inner edge of the ball holding portion at the tip of the tip. The applicator characterized by being filled with the oil-based gel ink composition as described in any one of 1-14.

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