JP4578080B2 - Follower with good fluidity and ballpoint pen having the same - Google Patents

Description

The present invention relates to a follower that is used at the rear end of ballpoint pen ink that is directly accommodated in an ink accommodating tube and has a good fluidity with a shear thinning index of 0.95 or more, and a ballpoint pen that uses the follower .

  When the inner diameter of the ink containing tube exceeds 2.8mm, the tube resistance is weak, so when the pen tip is left facing upward, a follower is required as a backflow prevention body to prevent ink from leaking out from the rear end of the refill. It becomes.

  Also, a follower is required to prevent ink scattering from the rear end of the refill when the pen is dropped.

  For this reason, the follower when using an ink containing tube having an inner diameter exceeding 2.8 mm requires a gel-like or paste-like one having poor fluidity in order to prevent backflow and ink scattering.

  On the other hand, if the inner diameter of the ink containing tube is 2.8 mm or less, the tube resistance is strong even when the pen tip is left facing upward, the ink does not leak from the rear end due to the effect of surface tension, and the pen drops. Ink is not easily scattered even when it is used.

  In addition, when the follower is used for an ink containing tube having an inner diameter of 2.8 mm or less, the tube resistance becomes strong, and there is a problem that the follower of the follower is less likely to occur at a low temperature or in a fast writing. .

  Therefore, the follower is not necessarily required when the ink containing tube has an inner diameter of 2.8 mm or less.

  However, the present inventor has developed a ballpoint pen that uses a volatile solvent, unlike a conventional oil-based ballpoint pen, but when using an ink that uses such a solvent having a high vapor pressure, It became clear that a follower was required at the rear end of the refill in order to suppress volatilization of the ink solvent from the end.

  When ink using a solvent with a high vapor pressure is used for a refill with an inner diameter of the ink containing tube of 2.8 mm or less, it is desirable to use a follower with good fluidity, contrary to the case where the diameter exceeds 2.8 mm. It is.

  Conventionally, as general followers, there are Patent Documents 1 to 11 and the like, and all of them have a function of preventing volatilization of a solvent from the rear end, prevention of backflow, and scattering of ink.

Japanese Patent Publication No. 6-33024 Japanese Patent No. 2859068 Japanese Patent No. 3016749 JP 7-216285 A JP-A-8-183286 JP 9-76687 A JP 11-42882 A JP 2001-63272 A JP-A-6-336588 JP 2000-177288 A JP-A-7-266780

  The follower disclosed above is assumed to be filled in an ink containing tube having an inner diameter of 2.8 mm or more. For this reason, a gelling agent that imparts shear thinning viscosity is an essential component.

  Further, there is no disclosure of a follower with good fluidity that does not impart a gelling agent that imparts shear thinning for the purpose of using an inner diameter of 2.8 mm or less.

Even when using an ink containing tube with a diameter of 2.8 mm or less, the present inventor satisfies the characteristics required for a follower such as drop resistance, upward reversal, and drooping, while the follower does not follow at low temperature or speed writing. It has been found that prevention of scumming can be achieved by using a follower with good fluidity and an appropriate viscosity range. The first object of the present invention is to provide a follower with good fluidity having this appropriate viscosity range.

  However, as we continue to develop using followers with good fluidity that balance the follower's followability, drop resistance, upward reversal, and drooping in this way, it will occur in conventional followers with poor fluidity. A new problem that couldn't have occurred. That is, there is a case in which the follower flows out from the rear end portion in winter especially for unknown reasons.

  Therefore, as a result of eagerly pursuing the cause of the follower flow-out, the inventor was affected by static electricity from the outside of the refill such as the outer shaft of the pen when using a follower with good fluidity. I found out that it was flowing out from the rear end.

In view of the circumstances as described above, the present invention solves the above problems, and even when a follower with good fluidity is used, the follower is affected by static electricity from the outside of the refill such as the outer shaft of the pen. A second object is to provide a ballpoint pen that does not flow out from the rear end.

As a result of further intensive studies to achieve the above-mentioned problems, the present inventor has found that the problems can be solved by characterizing the following points and completed the present invention.
(1) Containing one or more poly-α-olefins, which are synthetic oils having a viscosity at 40 ° C. of 200 mPa · s or more, the total amount of which is 80% by mass or more of all components, and the viscosity at 25 ° C. 1000~40000mPa · s, a shear thinning index at a shear rate of 1 to 10 / s is not less than 0.95, ballpoint pen follower, characterized in that does not contain a shear thinning imparting agent.
(2) In the above (1), one or more poly-α-olefins, which are synthetic oils having a viscosity at 40 ° C. of 200 mPa · s or more, are contained, and the total amount is 98% by mass or more of all components. The ballpoint pen follower.
(3) The above-mentioned (1) or containing at least one poly-α-olefin, which is a synthetic oil having a viscosity at 40 ° C. of 5000 mPa · s or more, the total amount of which is 50% by mass or more of all components The ballpoint pen follower according to any one of (2).
(4) The ballpoint pen follower according to any one of (1) to (3), wherein the poly-α-olefin is a polymer of an α-olefin mainly having 8 to 20 carbon atoms.

(5) An ink containing tube using a follower having a viscosity of 1000 to 40000 mPa · s at 25 ° C., a shear thinning index at a shear rate of 1 to 10 / s of 0.95 or more, and containing no shear thinning agent. A ballpoint pen having an inner diameter of 2.0 to 2.8 mm and a follower filling length of 10 mm or more.

( 6 ) The ballpoint pen according to ( 5 ), wherein the follower has a filling length of 12 mm or more.
( 7 ) A ballpoint pen using the follower according to ( 5 ) or ( 6 ) above, wherein the follower has a surface tension of 32.0 mN / m or more at 25 ° C.

(8) follower contain viscosity poly -α- olefin is more synthetic oils 200 mPa · s 1 or 2 or more at 40 ° C., the total amount thereof is not less than 80% by weight of the total components (5) The ball-point pen as described in-( 7 ).

( 9 ) The above ( 5 ) to ( 5 ) to ( 5 ) to ( 5 ) to ( 5 ) to ( 5 ) to ( 5 ) to ( 5 ) to ( 5 ) to ( 5 ) being used are non-aqueous ballpoint pen inks in which the solvent composed of alcohols and glycol monoethers. The ballpoint pen described in 8 ).
(10) Ballpoint pen ink in which a solvent composed of alcohols and glycol monoethers having a vapor pressure at 20 ° C. of 0.2 to 50 mmHg occupies 10 to 100% by mass of the ink solvent, and any one of claims 1 to 4 A ballpoint pen with an ink storage tube having an inner diameter of 2.0 to 2.8 mm.
(11) The ballpoint pen according to the above (10), wherein the ballpoint pen ink occupies 50 to 100% by mass of a solvent consisting of alcohol and glycol monoether of 0.2 to 50 mmHg.

According to the present invention, a follower with good fluidity is provided, and when using a follower with good fluidity mounted with the follower, the follower is affected by static electricity from the outside of the refill such as the outer shaft of the pen. It has become possible to provide a ballpoint pen that is prevented from flowing out from the rear end.

  The follower used in the ballpoint pen of the present invention does not cause a problem in follower followability at low temperatures or in quick writing even when the follower is mounted on an ink containing tube having an inner diameter of 2.8 mm or less and a strong tube resistance. In order to use a follower with good fluidity, those which basically do not contain a shear thinning agent are preferred.

  Even when a follower is mounted on an ink containing tube with an inner diameter of 2.8 mm or less, which has a strong resistance, the follower has an appropriate viscosity at 25 ° C. so as not to cause a problem in follower followability at low temperatures and fast writing. Is 1000 to 40000 mPa · s, preferably 3000 to 35000 mPa · s, more preferably 10,000 to 25000.

  A follower with a viscosity of less than 1000 mPa · s at 25 ° C., even if the ink containing tube has an inner diameter of 2.8 mm or less and has a strong tube resistance, the resistance to the drop impact of dropping the pen at room temperature is weakened and the follower dropped. Sometimes followers are scattered.

  A follower whose viscosity at 25 ° C. exceeds 40,000 mPa · s causes blurring due to poor follow-up of the follower when writing at a low speed of 5 ° C. or less.

  Even when a follower is mounted on an ink containing tube with an inner diameter of 2.8 mm or less and a strong resistance, the follower's appropriate shear-thinning index to prevent problems with follower followability at low temperatures and fast writing is It is 0.95 or more at a speed of 1 to 10 / s, preferably 0.97 or more.

  When the shear thinning index is 0.95 or less, the follower's followability at low temperatures and fast writing properties also deteriorates, causing blurring.

  In addition, although the degree of difference greatly depends on the viscosity of the follower, the amount of the follower that adheres to the wall surface when the ink is consumed increases, and a problem that the amount of the follower existing at the trailing edge of the ink decreases as the ink is consumed starts to occur.

The shear thinning index here refers to the degree of change in apparent viscosity when the shear rate is changed. When the shear thinning index n, shear stress τ, shear rate D, and apparent viscosity η are used, A relationship like the equation is obtained.
τ = ηD ⁿ −formula

  Examples of the base oil used in the follower used in the present invention include poly-α-olefin, mineral oil, polybutene and other hydrocarbons, silicone oil, and the like.

  The poly-α-olefin is a synthetic oil obtained by polymerizing an α-olefin, and typical α-olefins that are reaction starting materials include 1-octene, 1-decene, 1-dodecene, and the like. Industrially, 1-decene polymers are mainly used. The reaction starting material of poly-α-olefin used in the present invention is not particularly limited. However, if the carbon number of the α-olefin is small, the properties when left upward at high temperatures are not excellent. 8 or more are preferable, More preferably, it mainly has 8 to 20 carbon atoms.

  The viscosity of the poly-α-olefin used as the base oil for the follower of the present invention is preferably 200 mPa · s or more at 40 ° C., more preferably 500 mPa · s or more, and preferably 1000 to 50000 mPa · s. s is more preferable, and 1500 to 20000 mPa · s is still more preferable. Even when poly-α-olefins having a viscosity at 40 ° C. of less than 200 mPa · s are used in a certain amount or more, inversion tends to occur when left at high temperature.

  As the molecular weight of the poly-α-olefin increases, the affinity with the raw material decreases even at high temperatures, and reversal hardly occurs when left upward at high temperatures. For example, the total amount of the poly-α-olefin having a viscosity at 40 ° C. of 5000 mPa · s or more is preferably 50% by mass or more of all components, and further the poly-α- having a viscosity at 40 ° C. of 5000 mPa · s or more. More preferably, the total amount of olefins is 60% by mass or more, more preferably 70% by mass or more of the total components.

  The follower of the present invention is usually and desirably composed of one or more poly-α-olefins, which are synthetic oils having a viscosity at 40 ° C. of 200 mPa · s or more, and the total amount is 100% by mass. However, as a follower of this invention, the total amount should just be contained 80 mass% or more. More preferably, the poly-α-olefin having a viscosity at 40 ° C. of 200 mPa · s or more is 90% by mass or more, more preferably 98% by mass or more, most preferably more than 99.5% by mass, particularly 100% by mass. is there.

  Examples of the poly-α-olefin include Barrel Process Oil P-380 (Matsumura Oil Co., Ltd.), Barrel Process Oil P-1500 (Matsumura Oil Co., Ltd.), Barrel Process Oil P-2200 (Matsumura Oil Co., Ltd.), Barrel Process Oil P-10000 (manufactured by Matsumura Oil), Barrel Process Oil P-37500 (manufactured by Matsumura Oil), ExxonMobil SHF-403 (manufactured by ExxonMobil Chemical), ExxonMobil SHF-1003 (manufactured by ExxonMobil Chemical), SuperSyn 2150 (ExxonMobil Chemical), SuperSyn 2300 (ExxonMobil Chemical), SuperSyn 21000 (ExxonMobil Chemical), SuperSyn 23000 (ExxonMobil Chemical), and the like. Many of these commercially available poly-α-olefins are primarily 1-decene polymers.

  As the thickener used in the follower used in the present invention, a long chain hydrocarbon such as polybutene or polyisobutylene, a terpene resin or the like that does not impart shear thinning when mixed with a base oil can be used. .

  The follower of the present invention is preferably basically composed of a base oil and a mixture or thickener mixture.

  The inner diameter of the ink containing tube used in the ballpoint pen of the present invention is 2.0 to 2.8 mm, preferably 2.2 to 2.6 mm.

The ballpoint pen of the present invention has a phenomenon in which a follower flows out due to the influence of static electricity when a follower with good fluidity is used even in an ink containing tube having a strong tube resistance of 2.8 mm or less in order to obtain good followability. Solve .

  In addition, when the inner diameter of the ink containing tube is less than 2.0 mm, the tube resistance becomes too strong, so that even when the follower having the above viscosity range is used, no flow-out due to the influence of static electricity occurs.

  The material of the ink containing tube used in the ballpoint pen of the present invention does not significantly deteriorate the quality of the ballpoint pen due to the influence of the ink solvent or the follower solvent, or the quality of the ballpoint pen due to the impact from the outside or the moisture in the air. If it is not a thing, it will not specifically limit.

  Polypropylene or polyethylene is used as the material of the ink storage tube that comes into contact with the ink solvent or the follower solvent.

However, when the ink containing tube is made of a resin generally used for the above ballpoint pen ink containing tube (inner diameter 2.0 to 2.8 mm) , since these materials are very poor in conductivity, static electricity is generated due to friction or the like. When a follower that is easy to take on and has good fluidity is used, if the predetermined condition as in the present invention is not satisfied, there is a problem that the follower flows out from the rear end due to the influence of static electricity.

The filling length of the follower in the ballpoint pen (ink containing tube inner diameter 2.0 to 2.8 mm) of the present invention is 10 mm or more, preferably 12 to 30 mm, more preferably 14 to 25 mm.

  When the follower filling length is less than 10 mm, the follower flows from the rear end due to the influence of static electricity from the outside of the refill such as the outer shaft of the pen.

  The upper limit of the follower filling length is not particularly limited in terms of function. However, when a transparent resin is used for the ink containing tube, if it exceeds 30 mm, it is not preferable because the design looks worse.

  The follower filling length is the length from the liquid-liquid interface between the ink and the follower to the rear end of the follower in the refill.

  When the surface tension of the follower used in the present invention is 32.0 mN / m or more, the tube resistance becomes strong and the discharge due to static electricity is less likely to occur.

  The follower's surface tension is easily influenced by the substance having the lowest surface tension among the constituent components of the follower. Therefore, the follower raw material used in the ballpoint pen of the present invention uses a hydrocarbon having a high surface tension as a main component. It is preferable to use as all components.

  The surface tension was measured with a Wilnermy type (CBVP type) surface tension meter CBVP-A3 type (manufactured by Kyowa Interface Chemical Co., Ltd.).

  Specifically, hydrocarbons having a surface tension of 32.0 mN / m or more include Diana process oil PW-380 (manufactured by Idemitsu Kosan Co., Ltd.), barrel process oil P-1500 (manufactured by Matsumura Oil Co., Ltd.), and barrel process oil P-2200. (Matsumura Oil Co., Ltd.), Barrel Process Oil P-10000 (Matsumura Oil Co., Ltd.), Barrel Process Oil P-37500 (Matsumura Oil Co., Ltd.) and the like.

  A fluid follower having a viscosity of 1000 to 40000 mPa · s at 25 ° C. and a shear thinning index of 0.95 or more at a shear rate of 1 to 10 / s has an inner diameter of the ink containing tube of 2.0 to 2.8 mm. When the ballpoint pen refill is used, the follower does not flow out from the rear end of the ink containing tube due to the influence of gravity or a drop impact.

  However, when inserting the refill into the outer shaft with static electricity or when the outer shaft of the pen body consisting of the outer shaft and the refill is rubbed with a cloth etc. When the length is less than 10 mm, the follower flows from the rear end due to the influence of static electricity.

  This phenomenon did not occur when a general follower with poor fluidity having a shear thinning index of 0.8 or less was filled.

As a result of detailed verification of this phenomenon, it is presumed to be due to the following action.
The ink and the follower in the ink storage tube both form an electric double layer at the ink storage tube interface. For this reason, one charge is adsorbed on the surface of the solid, and the other charge balances the effect of the Coulomb attractive force with the charge adsorbed on the surface of the solid and the effect of the thermal diffusion motion of the liquid molecules and the charge itself. It has a distribution that does not leave the solid surface. In such an environment, when an electric field due to static electricity is applied from the outside, the balance of the arranged charges is lost, and the phenomenon of electroosmosis in which the liquid moves due to the influence appears.

  However, even in the case of a refill filled with only ink or only a follower inserted into an electrostatically charged outer shaft in an ink containing tube having an inner diameter of 2.0 to 2.8 mm and a strong tube resistance, each liquid does not flow out. It was a phenomenon that could not occur with ink alone and follower alone.

  In other words, when both the ink and the fluid follower are present in the ballpoint pen refill, it is a phenomenon that can occur extremely specially, and the presence of the liquid-liquid interface between the ink and the follower is an essential element.

  When observing a series of phenomena where flow-out occurs, immediately before the flow-out occurs due to the application of an electric field, the liquid moves due to electroosmosis, or the liquid-liquid interface between the ink and the follower deforms and the ink enters the follower. Is seen. It is presumed that the meniscus balance at the rear end of the follower is lost due to the intruding force and the flow starts.

  In addition, the liquid-liquid interface between the ink and the follower may be deformed because an electric double layer is also formed at the liquid-liquid interface and the liquid in this part moves directly by applying an electric field from the outside. .

  As the follower fill length increases due to the above action, the distance from the ink-follower liquid-liquid interface to the trailing edge of the follower increases, making it less susceptible to changes that occur at the ink-follower liquid-liquid interface. It is presumed that the outflow is less likely to occur.

When the follower with good fluidity provided by the present invention is used, if the follower filling length is 10 mm or more, the follower flow-out due to the influence of static electricity from the outside hardly occurs and it is almost a problem in actual use of the pen. Disappears.

  However, the follower filling length is more preferably 12 mm or more, and even more preferably 14 mm or more, in order to prevent outflow even when receiving an unexpectedly strong static electricity.

  When the outer shaft of the ballpoint pen is rubbed, the outer shaft is charged with static electricity. The strength of the static electricity is expressed by the surface potential and varies greatly depending on the material of the outer shaft, the frictional material, or the environment (particularly humidity) where the friction is performed.

  When the outer shaft made of acrylonitrile / styrene resin (AS) was rubbed with a cotton cloth in a relatively static electricity-friendly environment of about 30% humidity, the surface potential was 6-8 KV.

  The surface potential was measured with Statilon-DS3 (manufactured by Cicid Electrostatics).

  Further, as the follower surface tension increases, the balance of the meniscus at the rear end of the follower is less likely to be lost, so that it is presumed that the outflow is less likely to occur.

  Further, it is presumed that as the viscosity of the follower (especially in the low shear region) increases, the resistance to the force of the ink entering the follower increases, so that the outflow hardly occurs.

  Since this resistance is large, it is presumed that no outflow occurred when a conventional follower with poor fluidity including a gelling agent was used.

  When a follower with good fluidity is used for an ink containing tube having an inner diameter of 2.0 to 2.8 mm, it is affected by external static electricity regardless of whether it is a water-based ballpoint pen or an oil-based ballpoint pen.

  As described above, the present invention solves the problems caused in developing a ballpoint pen using a non-aqueous ink using a solvent having a high vapor pressure. Therefore, the follower of the present invention is a non-aqueous ballpoint pen ink. In particular, it is used together with a non-aqueous ball-point pen ink formed with a ball-point pen ink solvent in which a solvent composed of an alcohol or glycol monoether having a vapor pressure of 0.2 to 50 mmHg at 20 ° C. accounts for 10 to 100% by mass of the ink solvent. Sometimes it is particularly suitable.

  Solvents having a vapor pressure of 0.2 to 50 mmHg at 20 ° C. include alcohols such as ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tertbutyl alcohol, and 1-pen. Tanol, 2-pentanol, 3-pentanol, isopentyl alcohol, tert pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2 -Pentanol, 2-ethyl-1-butanol, n-heptanol, 2-heptanol, 3-heptanol and the like.

  As glycol monoethers, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether , Propylene glycol tertiary butyl ether, 3-methoxybutanol, 3-methyl-3-methoxybutanol and the like.

  Also, glycol monoesters can be used in the same manner as glycol monoether.

  When the solvent as mentioned above occupies 10 to 100% by mass of the ink solvent, further 30 to 100% by mass, especially 50 to 100% by mass, the volatilization of the ink solvent from the rear end occurs, and the ink A follower is required to prevent the quality from changing over time. For this purpose, the configuration of the follower of the present invention can be preferably used.

  The ballpoint pen ink composition suitable for using the follower of the present invention includes a color material and a resin in addition to the above solvent. The color material is adjusted by a pigment or dye or a combination thereof, and the resin can exhibit ball-point pen performance, and may be any material as long as it is not an unstable element in the ink.

  Moreover, various additives can also be used according to performance. The viscosity of the ink is desirably 20000 mPa · s or less at 25 ° C.

As described above, the case where the follower provided by the present invention is mainly used for a ballpoint pen having an inner diameter of the ink containing tube of 2.0 to 2.8 mm has been described. However, as described above, Is provided for the first time and constitutes the present invention.
The configuration of the follower of the present invention does not preclude the use of the ink for other inks such as water-based inks for water-based ballpoint pens that directly store ink in the ink storage tube in addition to non-water-based ballpoint pens.

  The structure of one example of the ball-point pen refill of FIG. 1 is shown typically. A ball-point pen tip 1 made of metal is liquid-tightly connected to one end of a transparent plastic ink containing tube 2. The structure of the chip 1 is various, but there are metal or ceramic balls (not shown) at the forefront, and the ink 3 in the ink containing tube 2 passes through the inside of the chip 1 and is the most advanced ball. Written. A follower 4 is mounted behind the ink 3 in the ink containing tube 2. When the ink 3 decreases, the follower 4 follows the movement of the rear end portion of the ink 3.

EXAMPLES Next, although an Example demonstrates this invention in detail, this invention is not limited by this Example.
The raw materials used in the examples and comparative examples will be described below.
(i) ExxonMobil SHF-403:
Poly-α-olefin. 25 ° C. viscosity 830 mPa · s (shear rate 3.8 / s),
25 ° C surface tension 31.4 mN / m.
(ii) Idemitsu polybutene 2000H: polybutene.
(iii) Tetrax 6T: polyisobutylene.

(iv) Barrel process oil P2200:
Poly-α-olefin. 25 ° C. viscosity 5300 mPa · s (shear rate 3.8 / s),
25 degreeC surface tension 33.2mN / m.
(v) Barrel process oil P10000:
Poly-α-olefin. 25 ° C. viscosity 24600 mPa · s (shear rate 3.8 / s),
25 ° C. surface tension 34.1 mN / m.
(vi) Barrel process oil P37500:
Poly-α-olefin. 25 ° C. viscosity 97800 mPa · s (shear rate 3.8 / s),
25 ° C surface tension cannot be measured.

(vii) Barrel process oil P1500:
Poly-α-olefin. 25 ° C. viscosity 2800 mPa · s (shear rate 3.8 / s)
(viii) Diana Process Oil PW-90:
mineral oil. 25 ° C. viscosity 180 mPa · s (shear rate 3.8 / s)
(ix) Diana Process Oil PW-8:
mineral oil. 25 ° C. viscosity 12 mPa · s (shear rate 3.8 / s)

In the examples of the present invention, the following ink was used.
<Ink>
Spiron violet C-RH (Hodogaya Chemical Co., Ltd.) 18.0% by mass
Polypinyl butyral BM-1 (manufactured by Sekisui Chemical Co., Ltd.) 1.0 mass%
SK resin (manufactured by Huls) 1.0% by mass
Activator 9.0% by mass
3-methoxy, 3-methyl, 1-butanol 64.0% by mass

Example 1
ExxonMobil SHF-403 (ExxonMobil Chemical) 85.0% by mass
Idemitsu Polybutene 2000H (made by Idemitsu Petrochemical Co., Ltd.) 15.0% by mass
These materials were heated and stirred at 90 ° C. for 30 minutes and then allowed to cool to room temperature to obtain 50 g of followers.

  The viscosity of the obtained follower at 25 ° C. was 2100 mPa · s (shear rate 3.8 / s), and the shear thinning index at a shear rate of 1 to 10 / s was 0.99. Moreover, the surface tension of the obtained follower was 31.4 mN / m.

  The ink, the follower, and an ink containing tube having an inner diameter of 2.4 mm were used, and a pen tip composed of a joint and a tip was used as a refill. The follower filling length at this time was 18 mm.

Example 2
ExxonMobil SHF-403 (manufactured by ExxonMobil Chemical) 83.5% by mass
Tetrax 6T (Nippon Petrochemical Co., Ltd.) 16.5% by mass
These materials were heated and stirred at 90 ° C. for 30 minutes and then allowed to cool to room temperature to obtain 50 g of followers.

  The viscosity of the obtained follower at 25 ° C. was 16000 mPa · s (shear rate 3.8 / s), and the shear thinning index at a shear rate of 1 to 10 / s was 0.98. Moreover, the surface tension of the obtained follower was 31.5 mN / m.

  The ink, the follower, and an ink containing tube having an inner diameter of 2.4 mm were used, and a pen tip composed of a joint and a tip was used as a refill. The follower filling length at this time was 12 mm.

Example 3
Barrel Process Oil P-2200 (Matsumura Oil Co., Ltd.) 80.0% by mass
Barrel Process Oil P-10000 (Matsumura Oil Co., Ltd.) 20.0% by mass
These materials were heated and stirred at 90 ° C. for 30 minutes and then allowed to cool to room temperature to obtain 50 g of followers.

  The viscosity of the obtained follower at 25 ° C. was 7500 mPa · s (shear rate 3.8 / s), and the shear thinning index at a shear rate of 1 to 10 / s was 1.00.

Moreover, the surface tension of the obtained follower was 33.2 mN / m.
The ink, the follower, and an ink storage tube having an inner diameter of 2.4 mm were used to form a refill in combination with a pen tip composed of a joint and a tip. The follower filling length at this time was 12 mm.

Example 4
Barrel Process Oil P-2200 (Matsumura Oil Co., Ltd.) 67.0% by mass
Barrel process oil P-37500 (Matsumura Oil Co., Ltd.) 33.0% by mass
These materials were heated and stirred at 90 ° C. for 30 minutes and then allowed to cool to room temperature to obtain 50 g of followers.

  The viscosity of the obtained follower at 25 ° C. was 16000 mPa · s (shear rate 3.8 / s), and the shear thinning index at a shear rate of 1 to 10 / s was 0.99. Moreover, the surface tension of the obtained follower was 33.2 mN / m.

  The ink, the follower, and an ink containing tube having an inner diameter of 2.4 mm were used, and a pen tip composed of a joint and a tip was used as a refill. The follower filling length at this time was 12 mm.

Example 5
Barrel Process Oil P-2200 (Matsumura Oil Co., Ltd.) 67.0% by mass
Barrel process oil P-37500 (Matsumura Oil Co., Ltd.) 33.0% by mass
These materials were heated and stirred at 90 ° C. for 30 minutes and then allowed to cool to room temperature to obtain 50 g of followers.

  The viscosity of the obtained follower at 25 ° C. was 16000 mPa · s (shear rate 3.8 / s), and the shear thinning index at a shear rate of 1 to 10 / s was 0.99. Moreover, the surface tension of the obtained follower was 33.2 mN / m.

The ink, the follower, and an ink storage tube having an inner diameter of 2.4 mm were used to form a refill in combination with a pen tip composed of a joint and a tip. The follower filling length at this time was 18 mm.
Comparative Example 1
Barrel process oil P-1500 (Matsumura Oil Co., Ltd.) 70.0 mass%
Diana Process Oil PW-8 (Idemitsu Kosan Co., Ltd.) 30.0% by mass
These materials were heated and stirred at 90 ° C. for 30 minutes and then allowed to cool to room temperature to obtain 50 g of followers.
The viscosity of the obtained follower at 25 ° C. was 630 mPa · s (shear rate 3.8 / s), and the shear thinning index at a shear rate of 1 to 10 / s was 1.00.

Comparative Example 2
Barrel process oil P-37500 (Matsumura Oil Co., Ltd.) 91.0% by mass
Idemitsu Polybutene 2000H (Idemitsu Petrochemical Co., Ltd.) 9.0% by mass
These materials were heated and stirred at 90 ° C. for 30 minutes and then allowed to cool to room temperature to obtain 50 g of followers. The viscosity of the obtained follower at 25 ° C. was 117,000 mPa · s (shear rate 3.8 / s), and the shear thinning index at a shear rate of 1 to 10 / s was 0.98.

Comparative Example 3
Barrel Process Oil P-2200 (Matsumura Oil Co., Ltd.) 70.0% by mass
Barrel process oil P-10000 (Matsumura Oil Co., Ltd.) 18.0% by mass
Aerosil R-972 (Nippon Aerosil Co., Ltd.) 8.0% by mass
Clearon P-105 (made by Idemitsu Kosan Co., Ltd.) 4.0% by mass
These materials were heated and stirred at 90 ° C. for 30 minutes and then allowed to cool to room temperature to obtain 50 g of a stirring solution. The stirring liquid was kneaded with a three-roll mill to obtain a follower. The viscosity of the obtained follower at 25 ° C. was 37,000 mPa · s (shear rate 3.8 / s), and the shear thinning index at a shear rate of 1 to 10 / s was 0.56.

(Evaluation methods and results)
The follower obtained by the blending and adjusting method as described above was combined with the non-aqueous ink shown below and evaluated by the following evaluation test, and the results shown in Table 1 were obtained.
After filling with ink and follower, use a centrifuge H-103N type centrifuge manufactured by Kokusan Centrifuge Co., Ltd. for 5 minutes at 2000 rpm so that centrifugal force is applied from the tail end of the pen toward the pen tip. Centrifugation was applied.

In Examples and Comparative Examples, an ink containing tube having an inner diameter of 2.4 mm and an inner wall of polypropylene was used, and a refill was obtained by combining with a pen tip composed of a joint and a tip. This refill was put on the shaft of UM-151 manufactured by Mitsubishi Pencil Co., Ltd. to make a pen body.
As a pen body combining non-aqueous ink and a follower, a tip having a ball diameter of 1.0 mm was used.

<Evaluation test>
1) Upward reversibility:
In a 50 ° C. environment, the pen tip was left facing for 1 month, and the presence or absence of reversal of ink and follower was observed. Evaluation was made according to the following criteria.
What did not reverse; ○
1 part reversed; △
Most reversed: ×

2) Dripping property In a 50 ° C. environment, ink was not filled, and only the follower was filled, and the pen tip was left facing for 1 month, and the degree of follower dripping (flowing along) the tube wall surface was observed. Evaluation was made according to the following criteria.
There was no dripping; ○
Some followers drooped and accumulated at the bottom, then integrated and blocked the entire ink reservoir again. △
A considerable number of followers drooped and moved downward. X

3) Quick writing:
Spiral writing (diameter: about 5 cm) was made on PPC paper, and the degree of blur was observed. Evaluation was made according to the following criteria.
There is almost no blur; ○
Some faintness; △
Slightly faint; ×

4) Diffusivity (i)
In a 50 ° C. environment, the pen tip was left facing for 1 month, and the state at the interface between the ink and the follower was observed. Evaluation was made according to the following criteria.
The interface is clear; ○
Difficult to understand interface boundaries; △
The boundary of the interface is extremely difficult to understand; ×

5) Diffusivity (ii)
In a 50 ° C. environment, the pen tip was left facing for 1 month, and the diffusion of the dye into the follower was observed. Evaluation was made according to the following criteria.
There is almost no diffusion of dyes in the followers: ○
Some diffusion of the dye in the followers: △
Dye diffusion to followers is remarkable: ×

6) Stickiness to wall surface A pen body was written for 300 m at a speed of 4.5 m / min, and the amount of follower at the trailing edge of the ink before and after writing was observed. Evaluation was made according to the following criteria.
No change in follower amount; ○
The amount of followers has changed slightly;
The amount of followers has changed significantly. ×

7) Resistance to drop impact The pen body was dropped 5 times continuously from a height of about 1 m, and the state of the rear end of the follower was observed. Evaluation was made according to the following criteria.
No change; ○
The interface at the rear end of the follower was disturbed, and the follower was scattered on the tube wall; ×

In Examples 1 to 6, no problem occurred.
Comparative Example 1 is a follower having a viscosity at 25 ° C. of 1000 mPa · s or less.
A paraffinic mineral oil having a low viscosity was used as a raw material other than poly-α-olefin. Because the viscosity of the follower is low and molecular motion occurs violently, the influence of substances with low molecular weight appears remarkably, the affinity with the ink raw material becomes strong, or the reverse occurs when left upward at high temperature became.

In addition, the phenomenon that the follower hangs down over the wall of the ink containing tube over time occurred because the cohesive force of the molecules was weakened and the surface tension was lowered.
Furthermore, due to the influence of low molecular weight substances or due to low viscosity and easy diffusion, the affinity with the ink raw material also increased, and the diffusion of ink dye into the follower was observed, and the ink and follower It was difficult to see the interface.
Moreover, the result that a follower scattered by a drop impact was obtained.

Comparative Example 2 is a follower having a viscosity at 25 ° C. of 40000 mPa · s or more.
The result of blurring due to poor follower tracking was obtained when writing in the speed writing. Further, although the shear thinning index was 0.95 or more, the amount of followers attached to the wall surface during ink consumption increased, and the amount of followers present at the trailing edge of the ink significantly decreased with ink consumption.

Comparative Example 3 is a follower having a shear thinning index of 0.95 or less at a shear rate of 1 to 10 / s.
The amount of follower adhering to the wall surface during ink consumption increased, resulting in a problem that the amount of follower present at the trailing edge of the ink decreased with ink consumption.
Because the shear thinning index is relatively low and the viscosity is relatively high, the amount of adhesion to the wall surface increases, and there is a problem that the amount of followers existing at the rear end portion of the ink is remarkably reduced as the ink is consumed.
In addition, a result of blurring due to poor follower tracking was obtained when writing in the speed writing.

Furthermore, the result was that a part of the follower was reversed because Aerosil R972, which is fine particle silica, and P105, which is a terpene resin, have a strong affinity with the ink raw material.
In addition, a phenomenon in which the interface between the ink and the follower is difficult to see may occur because Aerosil R972, which is fine particle silica, and P105, which is a terpene resin, have a strong affinity with the ink raw material.
As is apparent from the above results, the ballpoint pen followers of Examples 1 to 5 that fall within the scope of the present invention have upward reversal, sagging, quick writing, diffusibility, and ink as compared with the followers of Comparative Examples 1 to 3. It proved to be very excellent in terms of stickiness to the wall surface of the storage tube and resistance to drop impact.

Reference Example 11
The follower filling length of Example 1 was 7 mm.

Reference Example 12
The follower filling length of Example 2 was 7 mm.

Reference Example 13
The follower filling length of Example 3 was 7 mm.

Reference Example 14
The follower filling length of Example 4 was 7 mm.

(Evaluation methods and results)
The refill obtained above was evaluated for electrostatic resistance by the following evaluation test, and the results shown in Table 2 were obtained.
After filling with ink and follower, use a centrifuge H-103N type centrifuge manufactured by Kokusan Centrifuge Co., Ltd. for 5 minutes at 2000 rpm so that centrifugal force is applied from the tail end of the pen toward the pen tip. Centrifugation was applied.

And a pen body put refill of Examples and Reference Examples the axis of Mitsubishi Pencil Co. UM-151. Further, a chip having a ball diameter of 1.0 mm was used.

<Evaluation test a>
Rub it with a cloth so that the surface potential of the outer shaft is 6.0 KV, and insert the refill so that the pen tip faces upward.
The state of the rear end of the follower 3 minutes after insertion was observed.

<Evaluation test b>
Rub with a cloth so that the surface potential of the outer shaft is 8.0 KV, and insert the refill so that the pen tip faces upward.
The state of the rear end of the follower 3 minutes after insertion was observed.

Each test was evaluated according to the following criteria.
No change at the end of the follower: ○
The balance of the rear end of the follower is lost and changes in the meniscus appear: △
What followers flowed out: ×

Regarding the evaluation test a, in Examples 1 to 5, there was no change at the rear end of the follower.
Regarding the evaluation test b, in Examples 2 and 3, the balance of the rear end of the follower was lost, and a change appeared in the meniscus.

  In Example 2 and Example 4, the follower filling length and viscosity are the same, but the follower surface tension is different. Example 2 where the surface tension of the follower is low is somewhat inferior to the result of the evaluation test b compared to Example 4. From this result, it can be said that the higher surface tension is advantageous for the follower flow-out due to static electricity.

  In Example 3 and Example 4, the follower filling length and surface tension are the same, but the follower viscosity is different. Example 3 having a lower viscosity of the follower is somewhat inferior to the result of evaluation test b as compared with Example 4. From this result, it can be said that the higher the viscosity, the more effective the follower flows out due to static electricity.

In Example 1, the follower has the lowest viscosity and surface tension compared to the other examples.
However, since the follower filling length is as large as 18 mm, good results are obtained in the evaluation test b.

In Reference Examples 11 to 14, the follower filling length was as short as 7 mm, and therefore any good results were not obtained.
In Reference Example 14, the follower viscosity and surface tension were higher than those in the other Reference Examples , so somewhat favorable results were obtained in Evaluation Test a.

As is clear from the above results, the ballpoint pen mounted with the refills of Examples 1 to 5 that fall within the scope of the present invention is compared with the ballpoint pen mounted with the refills of Reference Examples 11 to 14 that fall outside the scope of the present invention. It turned out that it was very excellent in the influence of the static electricity from the outside of the refill such as the outer shaft of the.

The schematic diagram of one example of a ball-point pen refill is shown.

1 ... Chip 2 ... Ink receiving tube 3 ... Ink 4 ... Follower

Claims (11)

1 type or 2 types or more of poly-alpha-olefin which is a synthetic oil whose viscosity in 40 degreeC is 200 mPa * s or more is contained, the total amount is 80 mass% or more of all the components, and the viscosity in 25 degreeC is 1000-40000 mPa A ballpoint pen follower characterized by having a shear thinning index of 0.95 or more at s, a shear rate of 1 to 10 / s , and containing no shear thinning imparting agent .   2. The ball-point pen according to claim 1, comprising one or more poly-α-olefins, which are synthetic oils having a viscosity at 40 ° C. of 200 mPa · s or more, the total amount of which is 98% by mass or more of all components. Followers.   The poly-α-olefin, which is a synthetic oil having a viscosity at 40 ° C of 5000 mPa · s or more, is contained in one or more kinds, and the total amount is 50% by mass or more of all components. Ballpoint pen follower.   The follower for ball-point pens in any one of Claims 1-3 whose poly-alpha-olefin is a C8-C20 alpha olefin polymer mainly. Use a follower that has a viscosity of 1000 to 40000 mPa · s at 25 ° C., a shear thinning index of 0.95 or more at a shear rate of 1 to 10 / s , and does not contain a shear thinning agent. A ballpoint pen with a length of 2.0 to 2.8 mm and a follower filling length of 10 mm or more.   The ballpoint pen according to claim 5, wherein the follower has a filling length of 12 mm or more.   The ballpoint pen according to claim 5 or 6, wherein the follower has a surface tension of 32.0 mN / m or more at 25 ° C.   A follower contains 1 type, or 2 or more types of poly-alpha-olefin which is a synthetic oil whose viscosity in 40 degreeC is 200 mPa * s or more, The total amount is 80 mass% or more of all the components. The ballpoint pen according to claim 1.   The non-aqueous ball-point pen ink in which the solvent consisting of alcohols and glycol monoethers having a vapor pressure of 0.2 to 50 mmHg at 20 ° C. accounts for 10 to 100% by mass of the ink solvent is used. The ballpoint pen described in the item.   A ballpoint pen ink according to any one of claims 1 to 4, wherein a solvent comprising an alcohol or glycol monoether having a vapor pressure of 0.2 to 50 mmHg at 20 ° C occupies 10 to 100% by mass of the ink solvent; A ballpoint pen including a follower and having an ink containing tube having an inner diameter of 2.0 to 2.8 mm.   The non-aqueous ball-point pen according to claim 10, wherein the ball-point pen ink occupies 50 to 100% by mass of a solvent composed of 0.2 to 50 mmHg alcohol and glycol monoether.

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