JP6002011B2 - Ballpoint pen - Google Patents

Description

  The present invention relates to a ballpoint pen. Furthermore, it is related with the ball-point pen which is excellent in the anti-corrosion performance of a ball | bowl and can maintain high writing performance.

Conventional balls for ballpoint pens are mainly composed of silicon carbide, zirconia oxide, tungsten carbide, etc., but they are inexpensive and have high writing performance. Cemented carbide balls containing materials are widely used.
However, since metals such as cobalt, chromium, titanium, and nickel are mainly used as the binder, when used in water-based ballpoint pens, the binder may deteriorate over time due to corrosive components such as dissolved oxygen in the ink. When the binder is lost from the ball, the crystalline particles of tungsten carbide, the main component, drop off, or the eluted binder becomes a metal oxide and insolubilizes and adheres to the ball surface again. , So-called corrosion may occur. Since the corrugation on the ball surface becomes large due to the corrosion, the rotation of the ball is obstructed and the writing feel becomes heavy, or the ball seat is worn, and the smooth outflow of ink is obstructed and the handwriting is blurred. There was a thing.
In particular, although cemented carbide balls using cobalt or nickel as a metal binder are highly versatile, they have the drawback of being susceptible to corrosion over time in aqueous ballpoint pens due to the high metal binder content. .
Therefore, as a method for preventing the above-mentioned corrosion over time, a method of adding a sulfide compound or an amino derivative of benzotriazole into the ink is disclosed (for example, see Patent Documents 1 and 2).

JP 2004-115684 A Japanese Patent Publication No. 1-223512

However, the addition of the sulfide compound may cause problems such as generating an odor depending on the structure of the compound or precipitation due to long-term aging, making it difficult to obtain a sufficient corrosion-inhibiting effect. In addition, the amino derivatives of benzotriazole have low solubility in aqueous media, so they lack solubility stability in ink and are effective against copper-based metals, but are sufficient for carbide. The effect is not obtained.
Therefore, both of them are insufficient to prevent problems during writing, such as poor writing quality and faint writing.

  The present invention provides a ballpoint pen incorporating a water-based ink composition for ballpoint pens that can suppress the corrosion of cemented carbide balls over time and maintain excellent writing performance for a long period of time.

〔式中のｎは０又は１である〕
更に、前記水性インキ組成物のｐＨが７〜１２であること、水溶性有機溶剤がインキ組成物全量中５〜３０重量％の範囲で添加されることを要件とする。 The ballpoint pen of the present invention contains a water-based ink composition for ballpoint pens containing a colorant, water, and a benzotriazole derivative represented by the following general formula (1) or a salt thereof , with tungsten carbide as a main component and cobalt as a binder. It is required to use a cemented carbide ball including the tip of the writing .

[Wherein n is 0 or 1]
Furthermore, it is required that the pH of the water-based ink composition is 7 to 12, and that the water-soluble organic solvent is added in the range of 5 to 30% by weight in the total amount of the ink composition.

  By the present invention, elution of metallic materials such as cobalt constituting the carbide ball, and ball corrosion phenomenon such as adhesion of insoluble matter to the ball surface along with it can be suppressed for a long time, and the initial writing performance can be maintained. It is possible to provide a ballpoint pen incorporating a water-based ballpoint pen ink composition that can maintain a smooth writing feeling for a long period of time without causing blurring or line skipping in the handwriting.

The benzotriazole derivative represented by the general formula (1) or a salt thereof has a carboxyl group, thereby preventing a corrosive component in the ink from directly acting on the ball surface and effectively suppressing the metal elution described above. It is speculated that it is possible. Therefore, the corrosion phenomenon on the surface of the carbide ball can be suppressed for a long time.
Examples of the salt include alkali metal salts such as lithium, sodium and potassium, and amine salts such as alkanolamine and ammonia.
The benzotriazole derivative and its salt can be added in an amount of 0.05 to 5% by weight, preferably 0.1 to 4% by weight, based on the total amount of the ink composition.
If it is less than 0.05% by weight, it is difficult to obtain the desired effect, and even if it is added in excess of 5% by weight, no improvement in corrosion inhibition effect is observed, so no further addition is required.

As the colorant, all dyes and pigments that can be dissolved or dispersed in an aqueous medium can be used, and specific examples thereof will be exemplified below.
As the dye, an acid dye, a basic dye, a direct dye, or the like can be used.
Examples of the acid dye include New Coxin (CI. 16255), Tartrazine (CI. 19140), Acid Blue Black 10B (CI. 20470), Guinea Green (CI. 42085), Brilliant Blue FCF. (CI.42090), Acid Violet 6B (C.I.42640), Soluble Blue (C.I.42755), Naphthalene Green (C.I.44025), Eosin (C.I.45380), Phloxin (C.I. 45410), erythrosine (C.I. 45430), nigrosine (C.I. 50420), acid flavin (C.I. 56205) and the like are used.
Examples of basic dyes include chrysoidine (C.I. 11270), methyl violet FN (C.I. 42535), crystal violet (C.I. 42555), malachite green (C.I. 42000), Victoria blue FB ( CI 44045), rhodamine B (C.I. 45170), acridine orange NS (C.I. 46005), methylene blue B (C.I. 52015) and the like are used.
As direct dyes, Congo Red (C.I. 22120), Direct Sky Blue 5B (C.I. 24400), Violet BB (C.I. 27905), Direct Deep Black EX (C.I. 30235), Kaya Las Black G Conch (C.I. 35225), Direct Fast Black G (C.I. 35255), Phthalocyanine Blue (C.I. 74180) and the like are used.

Examples of the pigment include inorganic pigments such as carbon black and ultramarine blue, and organic pigments such as copper phthalocyanine blue and benzidine yellow, as well as water-dispersed pigments that are finely and stably dispersed in an aqueous medium in advance using a surfactant or the like. For example, C.I. I. Pigment Blue 15: 3B [Product Name: S.P. S. Blue GLL, pigment content 22%, manufactured by Sanyo Color Co., Ltd.], C.I. I. Pigment Red 146 [Product Name: S.P. S. Pink FBL, pigment content 21.5%, manufactured by Sanyo Dye Co., Ltd.], C.I. I. Pigment Yellow 81 [Product name: TC Yellow FG, pigment content about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.], C.I. I. Pigment Red220 / 166 [Product name: TC Red FG, pigment content: about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.].
As the fluorescent pigment, a fluorescent pigment in the form of fine particles of a synthetic resin in which various fluorescent dyes are formed into a solid solution in a resin matrix can be used.
In addition, pearl pigments, gold and silver metallic pigments, luminous pigments, white pigments such as titanium dioxide used in correction pens, metal powders such as aluminum, thermochromic compositions, photochromic compositions, and fragrances Examples thereof include capsule pigments directly or microencapsulated.

The thermochromic composition includes (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reversible thermochromic composition comprising a reaction medium that determines the temperature at which the color reaction occurs. The composition is suitable and is encapsulated in microcapsules and applied as a reversible thermochromic microcapsule pigment.
Examples of the reversible thermochromic composition include those described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-29398, etc., at a predetermined temperature (discoloration point). Discolored before and after, decolored state in the temperature range above the high temperature side discoloration point, color development state in the temperature range below the low temperature side discoloration point, only one specific state exists in the normal temperature range among the two states, The other state is maintained as long as the heat or cold required to develop the state is applied, but when the heat or cold is no longer applied, the hysteresis width returns to the state exhibited in the normal temperature range. A heat decolorable microcapsule pigment in which a reversible thermochromic composition having relatively small characteristics (ΔH = 1 to 7 ° C.) is encapsulated in a microcapsule can be applied.

Furthermore, large hysteresis characteristics (ΔH _B = 8 to 50 ° C.) described in JP- _B -4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, and the like. ), That is, when the shape of the curve plotting the change in the color density due to the temperature change is lowering the temperature from the lower temperature side than the color changing temperature range, as opposed to increasing the temperature from the lower temperature side. Reversible heat with color memory in a specific temperature range when the color changes in a low temperature range below the complete color development temperature or in a high temperature range above the complete color erase temperature. A heat-decolorable microcapsule pigment in which the color-changing composition is encapsulated in microcapsules is also applicable.
Specifically, as the reversible thermochromic composition having color memory, a complete color development temperature can be obtained only in a freezing room, a cold district, etc., that is, −50 to 0 ° C., preferably −40 to − 5 ° C., more preferably −30 to −10 ° C., and complete decoloring temperature obtained from a frictional heat generated by a friction body, a heating body such as a hair dryer, that is, 50 to 95 ° C., preferably 50 to 90 ° C. More preferably, by specifying the range of 60 to 80 ° C. and specifying the ΔH value of 40 to 100 ° C., it is possible to effectively function to maintain the color exhibited in the normal state (daily life temperature range).

The colorant may be used alone or in combination of two or more, and is used in the range of 1 to 25% by weight, preferably 2 to 15% by weight in the ink composition.

If necessary, a water-soluble organic solvent compatible with water can be used. This is used for improving the dissolution stability of the benzotriazole derivative, in addition to the conventional purpose of adjusting the handwriting drying property of the ink. Specifically, ethanol, propanol, butanol, glycerin, sorbitol, Triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl Ether acetate, sulfolane, 2-pyrrolidone, N-methyl-2-pyrrolidone, etc. It is below.
In addition, the said water-soluble organic solvent can be used 1 type or in combination of 2 or more types, and is used in 2-40 weight%, Preferably it is 5-30 weight%.

  Furthermore, a water-soluble resin can be added in order to impart adhesion and viscosity to the paper surface. Examples of the water-soluble resin include alkyd resins, acrylic resins, styrene maleic acid copolymers, cellulose derivatives, polyvinyl pyrrolidone, polyvinyl alcohol, and dextrin. The water-soluble resin can be used alone or in combination of two or more, and is used in the range of 1 to 30% by weight in the ink composition.

In addition, if necessary, pH adjusters such as inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, organic basic compounds such as water-soluble amine compounds, rust preventives such as benzotriazole, tolyltriazole and saponin , Carboxylic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) Preservatives or antifungal agents such as pyridine, urea, sorbit, mannitol, sucrose, glucose, reduced starch hydrolysates, wetting agents such as sodium pyrophosphate, antifoaming agents, fluorine-based interfaces that improve ink permeability An activator or a nonionic surfactant may be used.
Further, a lubricant can be added, such as metal soap, polyalkylene glycol fatty acid ester, ethylene oxide addition type cationic surfactant, phosphate ester type surfactant, N-acyl amino acid type surfactant, dicarboxylic acid type surfactant. , Β-alanine type surfactant, 2,5-dimercapto-1,3,4-thiadiazole and its salts and oligomers, 3-amino-5-mercapto-1,2,4-triazole, thiocarbamate, dimethyl A dithiocarbamate, α-lipoic acid, a condensate of N-acyl-L-glutamic acid and L-lysine, a salt thereof, or the like is used.
Further, oligomers of N-vinyl-2-pyrrolidone, oligomers of N-vinyl-2-piperidone, N-vinyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, ε-caprolactam, N-vinyl-ε-caprolactam By adding a thickening inhibitor such as an oligomer, it is possible to enhance the function in the intruding form.

Furthermore, a shear thinning agent can be added to the ink composition.
As the shear thinning agent, a water-soluble or dispersible substance is effective, and xanthan gum, welan gum, and succinoglycan whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose (average molecular weight) About 1,000 to 8 million), guar gum, locust bean gum and derivatives thereof, hydroxyethyl cellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000 based on alkyl esters of methacrylic acid, glucomannan, agar and carrageenan Carbohydrates having gelling ability extracted from seaweed such as benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymers, inorganic fine particles, nonionic surfactants having an HLB value of 8 to 12, and dialkylsulfosuccinic acid Metal salts and nets Can be exemplified a salt, further, be added in combination in the ink composition N- alkyl-2-pyrrolidone and anionic surfactant can have stable shear thinning.

The ink composition is adjusted to a pH applicable to a general-purpose water-based ballpoint pen, but is preferably adjusted to a neutral to alkaline region of pH 7 to 12, preferably a weak alkaline region of pH 7.1 to 10.
By adjusting to the pH, the benzotriazole derivative can exist more stably in the ink, so that ball corrosion can be more efficiently suppressed.

Furthermore, when the ink composition is filled in the shaft cylinder (ink storage tube), an ink backflow prevention body (liquid stopper) can be disposed at the rear end of the ink.
As the ink backflow preventer, either liquid or solid can be used, and examples of the liquid ink backflow preventer include non-volatile media such as polybutene, α-olefin co-oligomer, silicone oil, and refined mineral oil. If desired, silica, aluminum silicate, swellable mica, fatty acid amide and the like can be added to the medium. Moreover, a resin molding is mentioned as a solid ink backflow prevention body. The liquid and solid ink backflow preventers can be used in combination.

  The structure of the tip end (tip) of the ballpoint pen filled with the water-based ink composition for the ballpoint pen has conventionally used a general-purpose mechanism. For example, a ball in which the vicinity of the tip end of a metal pipe is pressed and deformed inward from the outer surface. A chip formed by holding a ball in the holding part, a chip formed by holding a ball in a ball holding part formed by cutting a metal material with a drill or the like, or a metal pipe or metal material A ball or the like held by a chip formed by cutting can be applied forward by a spring body.

For the balls, general-purpose metal balls obtained by sintering 4a, 5a, 6a group metals or their carbides together with a metal such as cobalt or nickel as a binder are used. A hard alloy ball is preferably used. Further, among the metals of the groups 4a, 5a, and 6a or carbides thereof, a cemented carbide ball using tungsten carbide (tungsten carbide) that is chemically stable and has high hardness as a main component is particularly preferably used. . In addition, titanium, vanadium, chromium, tantalum, and their carbides may be included as the metals of 4a, 5a, and 6a.
In general, in the case of using cobalt or nickel as the binder, since these metals are easily eluted in water-based ink, the ball surface becomes rough, and further, tungsten carbide is dropped due to the binder elution. The surface becomes rough. As a result, if the ball rotates while in contact with the ball seat, the wear of the seat becomes severe, so the writing feeling is impaired, and the gap between the ball and the ball holding portion in the axial direction (clearance) increases, causing ink outflow. Increasing the amount tends to cause problems such as thick handwriting and line skipping. However, when the water-based ink of the present invention is applied, the elution of the metal material (binding material) into the ink is suppressed, and the above-described problems are hardly caused.
In particular, the water-based ink composition applied in the present invention is extremely useful because it exhibits a very high effect with respect to a cemented carbide ball using cobalt as a binder, which easily causes ball corrosion.
The balls having a diameter in the range of 0.1 mm to 2.0 mm are preferably used.

The shaft cylinder to which the writing tip is connected directly or via a connecting member is a form capable of containing the water-based ink composition directly or impregnated in an impregnating material (filling), for example, polyethylene, A molded body made of a thermoplastic resin such as polypropylene or polyethylene terephthalate is preferably used in terms of low ink evaporation and productivity, but a metal processed body can also be used. Further, by using a transparent, colored transparent, or translucent molded body, the resin shaft can confirm the ink color, the remaining amount of ink, and the like.
When the ink composition is low in viscosity, the ink composition accommodated in the shaft cylinder includes a method of mounting an ink retaining member at the front of the shaft cylinder and storing the ink composition directly in the shaft cylinder, Examples of the method include impregnating the ink composition into a material body or a fiber processed body.
In addition, the said shaft cylinder may accommodate this refill in an outer shaft as a form of the refill for ball-point pens.

The ballpoint pen using the shaft tube can be applied to either a cap type or a retractable type. The retractable ballpoint pen is stored in the outer shaft with the writing tip provided on the ballpoint pen refill exposed to the outside air, and the writing tip protrudes from the opening of the outer shaft by the operation of the retracting mechanism. Anything can be used.
Examples of the operation method of the retracting mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the outer shaft rear end portion or the outer shaft side surface, and by pressing the knock portion, the writing pen tip portion of the ballpoint pen refill is caused to protrude or retract from the outer shaft front end opening portion, or on the outer shaft. By pressing the provided clip portion, a configuration in which the writing tip portion of the ballpoint pen refill is projected and retracted from the outer shaft front end opening portion can be exemplified.
The rotary type has a rotating part at the rear part of the outer shaft, and can be exemplified by a configuration in which the writing tip part of the ballpoint pen refill is projected and retracted from the outer shaft front end opening by turning the rotating part.
The slide type has a slide portion on the side surface of the shaft cylinder, and a configuration in which the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the outer shaft by operating the slide portion, or a clip portion provided on the outer shaft is provided. By sliding, the structure which makes the writing tip part of a ball-point pen refill appear and disappear from the outer-axis front-end opening part can be illustrated.
The retractable ballpoint pen may be a composite retractable ballpoint pen (refill exchange type) in which a plurality of ballpoint pen refills are accommodated in an outer shaft.

Examples will be described below, but the present invention is not limited to these examples.
The composition of the water-based ink for ballpoint pens of Examples and Comparative Examples is shown in the following table. In addition, the numerical value of a composition in a table | surface shows a weight part.

The contents of the raw materials in the table will be described along the note numbers.
(1) Product name: Water Pink 2 manufactured by Orient Chemical Industry Co., Ltd.
(2) Product name: Water Blue 105, manufactured by Orient Chemical Co., Ltd.
(3) Sanyo Color Co., Ltd., trade name: SS Blue GLL-E, solid content 22%
(4) 4.5 parts of 2- (2-chloroanilino) -6-di-n-butylaminofluorane as component (a), 1,1-bis (4'-hydroxyphenyl) n- as component (b) Reversible thermochromic composition comprising 4.5 parts of decane, 7.5 parts of 2,2-bis (4'-hydroxyphenyl) hexafluoropropane, and 50.0 parts of 4-benzyloxyphenylethyl caprate as the component (c) Microcapsule pigment encapsulating a product (T ₁ : −20 ° C., T ₂ : −9 ° C., T ₃ : 40 ° C., T ₄ : 57 ° C., ΔH: 63 ° C., average particle size: 2.5 μm, black to colorless Change color)
(5) Product name: Prisurf AL, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
(6) Arch Chemicals Japan, trade name: Proxel XL-2
(7) Product of Sanki Co., Ltd., trade name: Leozan (8) 1- (1 ′, 2′-dicarboxyethyl) benzotriazole [compound in which n in the general formula is 0]
(9) 1- (2,3-dicarboxypropyl) benzotriazole [a compound in which n in the general formula is 1]
(10) Thiazolidine (11) 2,2 ′-[[(Methyl-1H-benzotriazol-1-yl) methyl] imino] bisethanol

Preparation of Ink A In Examples 1 to 3 and Comparative Examples 1 to 3, each component was added to water, mixed and stirred, and then stirred at 400 ° C. for 1 hour with a disper at 20 ° C. and filtered to obtain each ink. Prepared.

Preparation of Ink B In Example 4 and Comparative Example 4, components other than the shear thinning agent were added to water, mixed and stirred, then the shear thinning agent was added, and at 20 ° C., 400 rpm with a disper, Each ink was prepared by stirring for 1 hour and filtering.

Preparation of Ink Backflow Preventing Body After adding 1.5 parts of fatty acid amide as a thickener to 98.5 parts of polybutene as a base oil, the mixture was kneaded with three rolls to obtain an ink backflow preventing body.

Production of Ballpoint Pen A The ink compositions of Examples 1 to 3 and Comparative Examples 1 to 3 were accommodated in an ink cartridge. In addition, a stainless steel chip that holds a ball (WC-Co cemented carbide ball) mainly composed of tungsten carbide with a diameter of 0.5 mm is attached to the comb-like ink retaining member (pen core) as a writing tip. Then, after the removable ink cartridge was fitted to the rear of the ink storage member, a sample ballpoint pen A was produced by screwing an outer shaft that covers and protects the ink tank. A detachable cap is fitted on the writing tip portion side.

Production of ballpoint pen B Stainless steel tip (henceforth a ball B (WC-Co cemented carbide ball)) containing the ink composition of Example 4 and Comparative Example 4 whose main component is tungsten carbide having a diameter of 0.4 mm. The ballpoint spring is housed in a ballpoint pen refill fitted to one end of a polypropylene pipe, and the ink backflow prevention body is disposed at the rear end, and then the ballpoint pen refill is incorporated into the outer shaft (protruding type). Sample ballpoint pen B was prepared.

The following tests were conducted using the ink composition and the sample ballpoint pen.
Ball Corrosion Test 5 g of each ink prepared was transferred to a sample bottle, covered with a cemented carbide ball (WC-Co system) having the same composition as that used for the sample ballpoint pen, and then placed in a 70 ° C. environment. Left for 30 days. Then, the state of each ball | bowl surface was confirmed with the optical microscope (1000-times multiplication factor) at room temperature.

Ink Stability Test After 5 g of each prepared ink was transferred to a sample bottle, covered, and allowed to stand in an environment of 50 ° C. for 30 days. Thereafter, the state of the ink inside was visually confirmed at room temperature.

Written test Each sample ballpoint pen that was confirmed to be writable was left in a 50 ° C environment for 60 days in a horizontal position, and then handwritten spiral circles were continuously written on the old JIS P3201 writing paper A. The writing feeling and the state of the handwriting were confirmed visually.
The results of the test are shown in the following table.

The evaluation of the test results is as follows.
Ball corrosion test ○: No change from the initial stage.
X: The surface is rough compared with the initial stage, or there is precipitation or deposits.
Ink stability test ○: No abnormality.
X: Sedimentation of particulate matter is observed.
Writing test ○: Writing was smooth and good handwriting was shown.
X: Written feeling is poor, many blurs and line jumps are seen in the handwriting, and seat wear is large and cannot be written.

Claims (3)

A cemented carbide ball containing a water-based ink composition for ballpoint pens containing a colorant, water, and a benzotriazole derivative represented by the following general formula (1) or a salt thereof, containing tungsten carbide as a main component and cobalt as a binder. A ballpoint pen used for writing tips.

[Wherein n is 0 or 1]   The ballpoint pen according to claim 1, wherein the pH of the water-based ink composition is 7 to 12. The ballpoint pen according to claim 1 or 2, wherein the water-soluble organic solvent is added in an amount of 5 to 30% by weight based on the total amount of the ink composition.