JP7301608B2 - writing instrument set - Google Patents

Description

The present invention relates to a writing instrument set.

A writing instrument set having a plurality of writing instruments and a case capable of accommodating the plurality of writing instruments is known (for example, Patent Document 1). The writing instrument set described in Patent Document 1 has three writing instruments. The case has an elongated opening at one end. The case accommodates the three writing instruments such that the rear ends of the aligned three writing instruments protrude from the open end. A slit extending in the axial direction is formed in each of both ends of the open end of the case. In the case, the two walls arranged facing each other between the two slits are elastically deformable such that the slit widens, ie the opening of the case becomes larger.

A protrusion is formed on a side surface near the rear end of each writing instrument. A small hole is formed in the wall of the case corresponding to each protrusion of the writing instrument when the writing instrument is housed. When the writing instrument is accommodated in the case, as the writing instrument is inserted into the case, the projection of the writing instrument presses the wall, thereby elastically deforming the wall. Elastic deformation of the wall portion is restored by the projection reaching and fitting into the small hole of the case. Similarly, when the writing instrument is taken out of the case, the wall section is elastically deformed, and when the protrusion of the writing instrument exceeds the opening end, the elastic deformation of the wall section is restored.

Japanese Utility Model Laid-Open No. 63-70391

When using the writing instrument, the writing instrument is stored in and taken out of the case, that is, attached and detached. Repeated attachment and detachment wears out the protrusions of the writing instrument due to friction with the surface of the wall. In particular, repeated attachment and detachment may cause the protrusion to be scraped off by the edge of the opening. In addition, repeated attachment and detachment plastically deforms the slit of the case, that is, the wall portion, leaving the opening enlarged. As a result, the fitting force or engagement force between the writing instrument and the case is reduced, and there is a risk that the writing instrument may come off unintentionally from the case. In addition, since the protrusion is provided at a conspicuous position on the side surface of the writing instrument, particularly on the side surface near the rear end, there are restrictions on the shape of the barrel of the writing instrument and restrictions on design such as patterns.

SUMMARY OF THE INVENTION An object of the present invention is to provide a writing instrument set whose engaging force does not decrease despite repeated attachment and detachment.

According to one aspect of the present invention, there is provided a writing instrument set including a plurality of writing instruments and a case capable of accommodating the plurality of writing instruments in an aligned state, wherein a first engaging portion is provided on the writing portion side of the writing instrument. is provided, and a second engaging portion is provided inside the case, and the first engaging portion and the second engaging portion are engaged or disengaged so that the writing instrument is attached to the case. A writing instrument set is provided wherein each is detachable.

The writing instrument further comprises a slide member, wherein the second engaging portion is provided on the slide member, the case has an operation portion, and operation of the operation portion causes the slide member to move rearward to remove the writing instrument. state.

The plurality of writing instruments may include a thermochromic writing instrument and a non-thermochromic writing instrument. In that case, the flexural modulus of the writing instrument main body of the thermochromic writing instrument and the flexural modulus of the writing instrument main body of the non-thermochromic writing instrument may differ by 300 MPa or more, preferably by 2 times or more. good. As a result, the feeling of writing on the main body of the writing instrument during writing is different, so that the difference between the thermochromic writing instrument and the non-thermochromic writing instrument can be recognized. The flexural modulus can be obtained by measurement according to JIS K7171.

Further, the plurality of writing instruments includes at least two writing instruments containing different achromatic inks, and the writing instrument main body of the writing instrument having a higher achromatic ink density is black, and the ink has a higher density of drawing lines. The writing instrument body of the thinner writing instrument may have a color other than black. By setting each color of the body of the writing instrument to black and a color other than black (for example, gray or white, which are achromatic colors with higher lightness than black), even a color blind person can easily recognize the color of the stored ink. .

ADVANTAGE OF THE INVENTION According to the aspect of this invention, there exists a common effect of providing the writing-instrument set which engagement force does not fall even if it attaches and detaches repeatedly.

FIG. 1 is a perspective view of a writing instrument housed in a writing instrument set according to an embodiment of the present invention. 2 is another perspective view of the writing instrument set of FIG. 1; FIG. FIG. 3 is a perspective view of a drawing instrument of the writing instrument set of FIG. 1; FIG. 4 is a perspective view of a writing instrument. 5 is a longitudinal sectional view of the writing instrument set of FIG. 1. FIG. FIG. 6 is a perspective view of a slide member. FIG. 7 is a perspective view of a cover member. 8 is an enlarged longitudinal sectional view of the front end of the writing instrument set of FIG. 1; FIG. FIG. 9 is an enlarged vertical cross-sectional view of the writing instrument set viewed from a different angle than FIG. 10 is an enlarged longitudinal sectional view of the front end of the writing instrument set of FIG. 3; FIG. FIG. 11 is an enlarged vertical cross-sectional view of the writing instrument set viewed from a different angle than FIG. 12 is an enlarged vertical cross-sectional view of the writing instrument set in a position different from that of FIG. 11. FIG. FIG. 13 is a perspective view of another case body. FIG. 14 is a front view of a clip member; FIG. 15 is a side view of the clip member; 16 is a cross-sectional view taken along line XX of FIG. 14. FIG. 17 is a cross-sectional view taken along line YY of FIG. 15. FIG. 18 is an enlarged view of part A of FIG. 16. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Corresponding elements are provided with common reference numerals throughout the drawings.

1 is a perspective view of a writing instrument 40 of a writing instrument set 1 according to an embodiment of the present invention in a stored state, FIG. 2 is another perspective view of the writing instrument set 1 of FIG. 1, and FIG. 4 is a perspective view of the writing instrument 40 of the writing instrument set 1 in a removed state; FIG. 4 is a perspective view of the writing instrument 40. FIG.

The writing instrument set 1 includes a case body 10, a cover member 20, a slide member 30 described later, three writing instruments 40, and a clip member 50. As shown in FIG. The clip member 50 is attached to the side surface of the case body 10 on the open end side by an adhesive or the like.

The cover member 20 is detachably attached to the case body 10 and covers a substantially rectangular opening formed on the side surface of the case body 10 on the closed end side. Thereby, the case main body 10 , the cover member 20 and the slide member 30 constitute the case 2 . The case 2 is open at one end and closed at the other end. The case 2 is configured to accommodate three writing instruments 40 in an aligned state. The case 2 may be configured to accommodate two or four or more writing instruments 40 .

An operating portion 21 is provided on the cover member 20 . As will be described later, the writing instrument set 1 is brought into the removed state of the writing instrument 40 shown in FIG. 3 by operating the operating portion 21 in the accommodation state of the writing instrument 40 shown in FIG. In this state, the user can take out the writing instrument 40 from the case 2 by gripping the protruding end of the writing instrument 40 .

Note that the clip member 50 may be omitted from the case 2 as shown in FIG. In this case, the flat surface 13 in the shallow recess provided in the case body 10 where the clip member 50 should be placed is exposed. Designs such as patterns and characters can be applied to the flat surface 13 . In this case, by transfer-printing a transparent film on which characters are written on the flat surface 13, even if the characters are applied to the flat surface 13, the characters are not easily peeled off. For example, the flat surface 13 may be printed with a company name or the like for distribution as a novelty item. Further, the flat surface 13 may be formed flush with the side surface of the case body 10 instead of inside the recess.

The writing instrument 40 includes a writing instrument main body 41 which is a tubular member formed in a cylindrical shape, a writing part 42 provided at one end of the writing instrument main body 41, and an outer peripheral surface of the writing instrument main body 41 on the writing part 42 side in the axial direction. and an identification portion 44 provided at the other end of the writing instrument main body 41 . A first engaging portion 45, which is an annular projection, is formed on the writing portion 42 side of the writing instrument 40 in the axial direction, more specifically, in the vicinity of the writing portion 42. As shown in FIG. A plurality of writing instruments 40 are housed in the case 2 so that each of the writing parts 42 is housed inside the case 2 .

In this specification, in the axial direction of the writing instrument 40, the writing section 42 side is defined as the "front" side, and the side opposite to the writing section 42 is defined as the "rear" side. In addition, in the axial direction of the case 2 , the side on which the writing part 42 of the writing instrument 40 is arranged in a state in which the writing instrument 40 is accommodated, that is, the closed end side is defined as the “front” side, and is the side opposite to the writing part 42 . , that is, the open end side is defined as the "rear" side.

Any writing instrument and combination of writing instruments may be employed as the writing instrument 40 as long as it has substantially the same outer shape that can be accommodated in the case 2 , particularly an outer shape that can be accommodated in an aligned state. In particular, the writing instrument 40 may adopt any shape as long as the first engaging portions 45 are formed at relatively the same locations. The writing instrument 40 is a thermochromic writing instrument such as a thermochromic ballpoint pen in which a refill, which is a writing body containing thermochromic ink and having a writing part 42 at one end, is accommodated in the writing instrument main body 41. may The writing instrument 40 may also be a non-thermochromic writing instrument such as a ballpoint pen, felt-tip pen, marker pen, mechanical pencil, brush pen, and fountain pen. For example, the plurality of writing instruments 40 housed in the writing instrument set 1 may include at least one thermochromic writing instrument and at least one non-thermochromic writing instrument.

In order to identify the plurality of writing instruments 40 accommodated in the writing instrument set 1, the rear portion of each writing instrument 40 has an identification portion 44 having a shape, pattern, or the like different from each other. For example, as the identification portion 44, each of the writing instruments 40 may be identified by making the number of annular grooves and the colors in the grooves as shown in FIG. 4 different. For example, the writing instrument 40 with one annular groove is a thermochromic ballpoint pen, the writing instrument 40 with two annular grooves is a thermochromic marking pen, and the writing instrument 40 with three annular grooves is a non-thermochromic ballpoint pen. may Similarly, in order to identify the plurality of writing instruments 40 housed in the writing instrument set 1, each of the writing instruments 40 may have a grip portion 43 having a different shape, pattern, or the like.

The plurality of writing instruments 40 housed in the writing instrument set 1 may include at least two writing instruments 40 containing inks of different achromatic colors. The writing instrument body 41 of the writing instrument 40 with the darker ink line density may be black, and the writing instrument body 41 of the writing instrument 40 with the lighter ink line density may be colored other than black, such as gray or white. The black color of the writing instrument main body 41 is determined visually. By making each color of the writing instrument main body 41 black and a color other than black, even a color-blind person can easily recognize the color of the stored ink.

Here, the achromatic inks are black, gray, and white. Specifically, a* and b* in the color space based on the L*a*b* color system are It means a color that is in the range of 5-5. As a method for measuring achromatic ink, the ink in the writing instrument 40 was spread on Clark Kent paper (ream weight 160 kg) using a bar coater (RDS06, Yasuda Seiki Seisakusho Co., Ltd.), and the spread sample was JIS Z 8781-. 4:2013 determine L*, a*, b*. For measurement, a spectrophotometer (SC-T (P), manufactured by Suga Test Instruments Co., Ltd.) is used, optical conditions: diffuse illumination 8° reception d8 method (excluding specular reflection), light source: 12 V 50 W halogen lamp, colorimetry Conditions: D65 light, 2° field of view, measurement temperature: −30° C., measurement area: 5φ (average of three measurements).

The drawn line density of the ink is evaluated by the lightness value, and the Munsell color system is used using a measuring device such as a general-purpose color difference meter (TC-8600A, manufactured by Tokyo Denshoku Co., Ltd.), and the paper surface at -30 ° C. (former JIS P3201: fine paper made from 100% chemical pulp, basis weight range of 40 to 157 g/m ² , whiteness of 75.0% or more); writing speed of 4.5 m/min; Measure on a drawn line drawn at 1 mm. The ink with the higher lightness value is evaluated as the ink with the higher drawn line density.

When the plurality of writing instruments 40 housed in the writing instrument set 1 includes the thermochromic writing instrument 40 and the non-thermochromic writing instrument 40, the bending elastic modulus of the writing instrument body 41 of the thermochromic writing instrument 40 and the thermal discoloration The flexural modulus of the writing instrument main body 41 of the writing instrument 40 which is not flexible may differ by 300 MPa or more, preferably by a factor of 2 or more. As a result, the feeling of writing on the writing instrument main body 41 during writing is different, so that the difference between the thermochromic writing instrument 40 and the non-thermochromic writing instrument 40 can be recognized. The flexural modulus can be obtained by measurement according to JIS K7171.

FIG. 5 is a longitudinal sectional view of the writing instrument set 1 of FIG. 6 is a perspective view of the slide member 30. FIG. The case body 10 has two holding projections 11 formed on the front end surface inside and two guide projections 12 formed on the opposing wall portions. Each holding projection 11 is configured to hold one end of the spring 51 . The guide projection 12 extends along the axial direction and is configured to guide the movement of the writing instrument 40 inserted into the case 2 in the front-rear direction.

A slide member 30 is arranged inside the case body 10 so as to be movable in the front-rear direction. Movement of the slide member 30 in the front-rear direction is restricted within a predetermined range by the cover member 20 attached to the case body 10, as will be described later.

The slide member 30 is formed with three aligned insertion holes 31 facing rearward and extending in the axial direction. Each of the insertion holes 31 is configured to receive the front end of the corresponding writing instrument 40 inserted into the case 2 . The slide member 30 is also formed with two holding holes 32 facing forward and extending in the axial direction at positions corresponding to the insertion holes 31 at both ends. Each holding hole 32 is configured to receive a spring 51 . One end of the spring 51 received in the holding hole 32 is supported by the support surface 33 which is the annular bottom surface of the holding hole 32 . Therefore, the front end of spring 51 is held by holding projection 11 and the other end of spring 51 is supported by support surface 33 . Thereby, the slide member 30 is always urged rearward by the two springs 51 .

The slide member 30 will be further described with reference to FIG. A second engagement portion 34 consisting of four projections evenly arranged along the circumferential direction is formed on the inner peripheral surface near the opening end of each insertion hole 31 . A locking piece 35 is provided on the side surface of the slide member 30 corresponding to the operation portion 21 of the cover member 20 in the case 2 . The locking piece 35 is a beam-like member defined by a penetrating U-shaped groove 36 and extending rearward. A first locking surface 37 is formed on the rear end surface of the locking piece 35 . In addition, an inclined surface 38 inclined rearward is formed on the surface of the locking piece 35 . Furthermore, two second locking surfaces 39 defined by two recesses or two projections are formed on the rear end surface of the slide member 30 .

7 is a perspective view of the cover member 20. FIG. In the perspective view of FIG. 7, the cover member 20 is viewed from inside. The operating portion 21 is provided on the cover member 20 as described above. Specifically, the operating portion 21 is a beam-shaped member defined by a penetrating arcuate groove 22 and extending rearward. An arcuate protrusion 23 is formed on the inner surface of the rear end portion of the operating portion 21 . Two parallel rib projections 24 extending rearward along the axial direction are formed on the inner surface of the cover member 20 behind the projections 23 . A first engaged surface 25 is formed on the front end surface of each rib projection 24 . A concave portion 26 is formed in the intermediate portion of the rib projection 24 . The inner surface of the rear end portion of the cover member 20 corresponding to the second locking surface 39 of the slide member 30 is formed with two second locked surfaces 27 defined by two projections and facing forward. there is

8 is an enlarged longitudinal sectional view of the front end portion of the writing instrument set 1 of FIG. 1, and FIG. 9 is an enlarged longitudinal sectional view of the writing instrument set 1 viewed from a different angle from FIG. 10 is an enlarged longitudinal sectional view of the front end portion of the writing instrument set 1 of FIG. 3, FIG. 11 is an enlarged longitudinal sectional view of the writing instrument set 1 viewed from a different angle from FIG. 10, and FIG. FIG. 12 is an enlarged vertical cross-sectional view of the writing instrument set 1 at a position different from that of FIG. 11;

FIGS. 1, 8 and 9 show the writing instrument set 1 in a state in which three writing instruments 40, which are ballpoint pens, are housed. In the accommodated state, the slide member 30 is at an advanced position within the case 2 . Therefore, the rear end of the writing instrument 40 protrudes slightly from the open end of the case 2 to such an extent that the writing instrument 40 cannot be taken out by the user's grip. At this time, the rear end of the writing instrument 40 does not have to protrude.

Referring particularly to FIG. 9, when the writing instrument 40 is housed, the slide member 30 is locked against the case 2 against the biasing force of the spring 51 . That is, the slide member 30 biased rearward has the first locking surface 37 of the locking piece 35 locked to the first locked surface 25 of the cover member 20 . Thereby, the rearward movement of the slide member 30 is restricted.

By operating the operating portion 21 in the stowed state of the writing instrument 40 , the slide member 30 moves rearward and the writing instrument 40 is taken out. In the present embodiment, the operation of the operation section 21 means pressing the operation section 21 . When the operating portion 21 is pressed, the locking piece 35 pressed by the operating portion 21 bends inward, and the first locking surface 37 of the locking piece 35 and the first locked surface 25 of the cover member 20 are engaged. stop is released. As a result, the sliding member 30 is moved rearward by the biasing force of the spring 51, and the writing instrument 40 is taken out.

3 and 10 to 12 show the writing instrument set 1 with the writing instrument 40 taken out. In the removed state, the slide member 30 is at a retracted position within the case 2 . Therefore, the rear end portion of the writing instrument 40 protrudes from the open end of the case 2, and the user can grasp and take out any writing instrument 40. As shown in FIG.

Referring particularly to FIG. 11, when the writing instrument 40 is taken out, the slide member 30 is locked against the case 2 against the further biasing force of the spring 51. As shown in FIG. That is, the slide member 30 biased rearward is locked by the second locking surface 39 against the second locked surface 27 of the cover member 20 . Further rearward movement of the slide member 30 is thereby restricted. In other words, the rearward movement of the slide member 30 in the transition from the housed state to the taken-out state is achieved by the collision of the second locking surface 39 of the slide member 30 with the second locked surface 27 of the cover member 20. Stop.

The rearward movement of the slide member 30 during the transition from the housed state to the removed state is damped by the frictional resistance between the inclined surface 38 and the protrusions 23 of the cover member 20 . That is, while the slide member 30 is moving rearward, the inclined surface 38 of the slide member 30 and the projection 23 of the cover member 20 are always in contact with each other. Further, since the slide member 30 has the sloped surface 38 that slopes rearward, the more the slide member 30 moves rearward, the more the protrusions 23 of the cover member 20 move relative to the sloped surface 38 . pressed down. As a result, the slide member 30 decelerates as it goes rearward, and the transition to the take-out state is completed. Such a deceleration action prevents the slide member 30 from suddenly stopping due to a collision, thereby preventing damage to parts due to impact and preventing the writing instrument 40 from unintentionally jumping out of the case 2 due to inertial force.

Referring to FIG. 12, when the writing instrument 40 is taken out, the locking piece 35 of the slide member 30 is housed in the recess 26 of the cover member 20 . That is, the inward deflection of the locking piece 35 due to the pressing of the operating portion 21 is restored. That is, no unnecessary force is applied to the locking piece 35 in the stored state and the removed state. Therefore, the locking piece 35 is prevented from being deformed for a long time, and plastic deformation of the locking piece 35 is prevented.

It should be noted that the storage state and the extraction state may be changed by performing other operations instead of pressing as the operation of the operation unit. For example, as the operation of the operating portion, the slide member 30 may be moved forward and backward by sliding the operating portion forward and backward.

Each of the writing instruments 40 can be attached to and detached from the case 2 by engaging or disengaging the first engaging portion 45 of the writing instrument 40 and the second engaging portion 34 of the case 2, that is, the sliding member 30. is. That is, when the writing instrument 40 is inserted into the insertion hole 31 of the slide member 30 , the first engaging portion 45 of the writing instrument 40 climbs over the second engaging section 34 by strongly pushing the writing instrument 40 . As a result, the first engaging portion 45 and the second engaging portion 34 are engaged with each other so as not to come off with a light force. On the other hand, when the writing instrument 40 is removed from the case 2, the writing instrument 40 is strongly pulled so that the first engaging portion 45 of the writing instrument 40 climbs over the second engaging section 34 again. As a result, the first engaging portion 45 and the second engaging portion 34 are disengaged.

In the writing instrument set 1, a first engaging portion 45 is provided on the writing portion 42 side of the writing instrument 40 in the axial direction, particularly near the writing portion 42, and a corresponding second engaging portion 34 is provided inside the case 2. This provides an effect that the engaging force does not decrease even if the writing instrument 40 is repeatedly attached and detached. Further, the first engaging portion 45 and the second engaging portion 34 do not come into contact with other parts or the like when the writing instrument 40 is repeatedly attached and detached. Furthermore, since the first engaging portion 45 is provided on the writing portion 42 side of the writing instrument 40 in the axial direction, particularly in the vicinity of the writing portion 42, restrictions on the shape of the writing instrument main body 41 of the writing instrument 40, patterns, etc. There is also an effect that there is no restriction on the design of

The first engaging portion and the second engaging portion may employ any configuration as long as the effects described above can be achieved and they can be engaged and disengaged with each other. For example, the first engaging portion 45 may be a plurality of projections evenly arranged along the circumferential direction, and the second engaging portion 34 may be an annular projection. Alternatively, one of the first engaging portion and the second engaging portion may be a protrusion, and the other of the first engaging portion and the second engaging portion may be a recess corresponding to the protrusion.

14 is a front view of clip member 50, FIG. 15 is a side view of clip member 50, FIG. 16 is a cross-sectional view taken along line XX of FIG. 14, and FIG. 18 is a cross-sectional view taken along line YY, and FIG. 18 is an enlarged view of part A of FIG. 16. FIG.

The clip member 50 is formed by deforming a single metal plate into a substantially U shape. The clip member 50 has a mounting plate 51 attached to the side surface of the case body 10 and a gripping plate 52 for gripping an article between the mounting plate 51 and the gripping plate 51 . A rear end portion of the gripping plate 52 is formed with a bent portion 52 a that is bent in a direction away from the mounting plate 51 . Since the clip member 50 has the bent portion 52a, insertion of an article such as paper between the mounting plate 51 and the gripping plate 52 is facilitated.

A rectangular opening 53 with rounded corners extending along the center line of the clip member 50 is formed on the front side of the gripping plate 52 . The mounting plate 51 is formed with a protrusion 54 that is exposed from the opening 53 and extends rearward along the center line beyond the rear end of the opening 53 from a position corresponding to the front end of the opening 53 . there is The protrusions 54 are formed by forming minute recesses 51a on the opposite surface of the mounting plate 51, as shown in FIG. By forming the convex portion 54 on the mounting plate 51, the strength against deformation such as warping of the mounting plate 51 can be increased. Therefore, when the clip member 50 is attached to the case body 10, for example, when the clip member 50 is adhered, it is possible to prevent the mounting plate 51 from being deformed due to stress or the like applied to the adhered surface.

As shown in FIG. 18 , the projection 54 of the mounting plate 51 and the gripping plate 52 are separated from each other near the rear end of the opening 53 . Therefore, the convex portion 54 and the grip plate 52 are not in contact with each other and are separated from each other along the length direction of the convex portion 54 . In other words, the opening 53 is formed so that the projection 54 and the gripping plate 52 do not come into contact with each other, that is, so as to prevent contact. Therefore, the mounting plate 51 is designed so that the article can be firmly gripped at places other than the opening 53 and the protrusion 54, for example, at the left and right edges of the protrusion 54 (edges positioned above and below the protrusion 54 in FIG. 14). And the gripping plate 52 can be configured to be in close contact with each other. Furthermore, referring to the cross-sectional view shown in FIG. 17, since the convex portion 54 slightly protrudes into the opening portion 53, when a thin sheet of paper or the like is gripped, the paper or the like will not be shaped like the convex portion 54. It deforms according to the , and can grip paper etc. more firmly.

A plurality of projections 54 may be provided as long as deformation of the mounting plate 51 can be prevented, and the arrangement and shape of the mounting plate 51 can be arbitrarily adopted. Further, the corresponding openings 53 may have any shape as long as they are formed so that the gripping plate 52 and the convex portion 54 do not come into contact with each other and as long as the adhesion between the mounting plate 51 and the gripping plate 52 can be ensured. can be formed with

The material of the case 2, that is, the case main body 10 and the cover member 20 is preferably hard plastic such as ABS and polycarbonate.

The material of the writing instrument main body 41 is a plastic material different from the material of the case 2 and softer than the material of the case 2 . More specifically, the polypropylene resin should be used in an amount of 50% by mass or more, and the tensile modulus (JIS K 7161:2014-1) should be 70 MPa or more. Due to this characteristic, there is little resistance when discoloring or erasing the handwriting formed by thermochromic ink by rubbing it, and sufficient frictional heat can be obtained even with a light force, and furthermore, it is possible to erase fine parts. is also possible.

Polypropylene-based resins that can be used as the base material for the shaft include, for example, propylene homopolymers; propylene and other small amounts of α-olefins (e.g., octene, 4-methyl-1-pentene, etc.) (including block copolymers and random copolymers); and the like. As the polypropylene-based resin, one or a mixture of two or more of these can be used. By using 50% by mass or more of the polypropylene-based resin in the total amount of the shaft, the effect can be exhibited, and if the polypropylene-based resin is less than 50% by mass, the effect cannot be exhibited.

Examples of resins that can be used in addition to the polypropylene-based resins include polyethylene and ionomers. These resins are preferably contained in an amount of 0.5 to 30% by mass in the total amount of the shaft in order to further exert the effect.

Further, it is preferably selected from rosin-based resins, terpene-based resins, petroleum-based resins, phenol-based resins, coal-based resins, and xylene-based resins in terms of adjusting adhesiveness and exerting sufficient frictional heat even with a light force. At least one resin may be included. Among these resins, those with a molecular weight of several hundred to several thousand are selected, and by adding them to the blending system of the polypropylene-based resin, which is the main component, the shaft can be given stickiness and the effect can be further exhibited. can. Specifically, the molecular weight of natural resins such as rosin-based resins and terpene-based resins, petroleum-based resins, phenol-based resins, coal-based resins, and xylene-based resins is preferably 500 to 5,000, more preferably 700 to 4,000. The above various resins can be used.

Rosin-based resins include gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, modified rosin glycerin, pentaerythritol ester, etc. Terpene-based resins include α-pinene, β-pinene-based, dipentene-based terpene resins, aromatic modified terpene resins, terpene phenol resins, hydrogenated terpene resins, and the like. Among these resins, polymerized rosins, terpene resins, hydrogenated terpene resins, aromatic modified hydrogenated terpene resins, and terpene phenol resins are preferred from the viewpoint of further stability.

Petroleum resins are, for example, cracked oil fractions containing unsaturated hydrocarbons such as olefins and diolefins, which are by-produced together with petrochemical basic raw materials such as ethylene and propylene by thermal cracking of naphtha in the petrochemical industry. Obtained by polymerization with a Friedel-Crafts type catalyst. The petroleum-based resins include aliphatic petroleum resins obtained by (co)polymerizing a _C5 fraction obtained by thermal decomposition of naphtha, and (co)polymerizing a _C9 fraction obtained by thermal decomposition of naphtha. Aromatic petroleum resins obtained by the above, copolymer petroleum resins obtained by copolymerizing the _C5 fraction and _C9 fraction, hydrogenated petroleum resins, alicyclic compound petroleum resins such as dicyclopentadiene petroleum resins, Petroleum-based resins such as styrene-based resins such as styrene, substituted styrene, and copolymers of styrene and other monomers can be mentioned. _C5 fractions obtained by pyrolysis of naphtha usually contain olefinic Hydrocarbons, diolefinic hydrocarbons such as 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, and 3-methyl-1,2-butadiene are included. In addition, the aromatic petroleum resin obtained by (co)polymerizing the _C9 fraction is a resin obtained by polymerizing an aromatic having a carbon number of 9 with vinyl toluene and indene as the main monomers, and is a resin obtained by thermal decomposition of naphtha. Specific examples of the C ₉ fraction obtained by the above include styrene homologues such as α-methylstyrene, β-methylstyrene and γ-methylstyrene, and indene homologues such as indene and coumarone. Trade names include Petrogin made by Mitsui Chemicals, Petolite made by Mikuni Chemicals, Neopolymer made by JX Nippon Oil & Energy, Petcol made by Tosoh, and Petrotac.

Further, a modified petroleum resin obtained by modifying a petroleum resin composed of the above-mentioned _C9 fraction is preferably used as a resin that achieves a high level of both adhesiveness and adhesiveness durability. Modified petroleum resins include _C9 petroleum resins modified with unsaturated alicyclic compounds, _C9 petroleum resins modified with compounds having hydroxyl groups, and _C9 petroleum resins modified with unsaturated carboxylic acid compounds. be done. Preferable unsaturated alicyclic compounds include cyclopentadiene and methylcyclopentadiene, and dicyclopentadiene, cyclopentadiene/methylcyclopentadiene co-dimer, tricyclopentadiene and the like as Diels-Alder reaction products of alkylcyclopentadiene. and dicyclopentadiene is particularly preferred. A dicyclopentadiene-modified _C9 petroleum resin can be obtained by thermal polymerization or the like in the presence of both dicyclopentadiene and a _C9 fraction. Examples of the dicyclopentadiene-modified _C9 petroleum resin include Neopolymer 130S manufactured by JX Nikko Nisseki Energy.

Moreover, alcohol compounds and phenol compounds are mentioned as compounds having a hydroxyl group. Specific examples of alcohol compounds include alcohol compounds having double bonds such as allyl alcohol and 2-butene-1,4 diol. As the phenol compound, alkylphenols such as phenol, cresol, xylenol, pt-butylphenol, p-octylphenol, and p-nonylphenol can be used. These hydroxyl group-containing compounds may be used alone or in combination of two or more.

Hydroxyl group-containing _C9 petroleum resins are produced by thermally polymerizing a (meth)acrylic acid alkyl ester or the like together with a petroleum fraction to introduce an ester group into the petroleum resin, and then reducing the ester group. It can also be produced by a method of hydrating the double bond after remaining or introducing the double bond.

As the hydroxyl group-containing _C9 petroleum resin, those obtained by various methods as described above can be used, but from the viewpoint of performance and production, it is preferable to use a phenol-modified petroleum resin. Petroleum resin is obtained by cationic polymerization of _C9 fraction in the presence of phenol, is easy to modify, and is inexpensive. Examples of phenol-modified _C9 petroleum resins include Neopolymer-E-130 manufactured by JX Nikko Nisseki Energy.

Furthermore, as the _C9 -based petroleum resin modified with an unsaturated carboxylic acid compound, a C9 _- based petroleum resin modified with an ethylenically unsaturated carboxylic acid can be used. Representative examples of such ethylenically unsaturated carboxylic acids include (anhydride) maleic acid, fumaric acid, itaconic acid, tetrahydro(anhydride) phthalic acid, (meth)acrylic acid and citraconic acid. The unsaturated carboxylic acid-modified _C9 petroleum resin can be obtained by thermally polymerizing a _C9 petroleum resin and an ethylenically unsaturated carboxylic acid. Maleic acid-modified C9 _- based petroleum resins are preferred here.

Examples of unsaturated carboxylic acid-modified _C9 petroleum resins include Neopolymer 160 manufactured by JX Nikko Nisseki Energy. Also, a copolymer resin of a _C5 fraction and a _C9 fraction obtained by thermal decomposition of naphtha can be preferably used. Here, the _C9 fraction is not particularly limited, but is preferably a _C9 fraction obtained by thermal cracking of naphtha. Specifically, Struktol series TS30, TS30-DL, TS35, TS35-DL and the like manufactured by SCHILL & SEILACHER can be mentioned.

Examples of the phenol-based resin include alkylphenol-formaldehyde-based resins and rosin-modified resins thereof, alkylphenol-acetylene-based resins, modified alkylphenol resins, terpenephenol resins, and the like. (manufactured by Kasei Kogyo Co., Ltd.), pt-butylphenol acetylene resin under the trade name of Colecin (manufactured by BASF), and the like. Coal-based resins include coumarone-indene resins, and xylene-based resins include xylene formaldehyde resins. In addition, polybutene can also be used as a resin having tackifying properties. Among these resins, from the viewpoint of adhesiveness and stickiness persistence, copolymer resins of C5 _fraction and _C9 fraction, aromatic petroleum resins obtained by (co)polymerizing _C9 fraction, Phenolic resins and coumarone-indene resins are preferred.

These resins preferably have a softening point of 200.degree. C. (measurement method: ASTM E28-58-T) or less, more preferably in the range of 80.degree. If the softening point exceeds 200°C, the processability may be deteriorated, and if it is lower than 80°C, the adhesion performance may be deteriorated. From these points of view, the softening point is more preferably in the range of 90 to 120°C. The above resins may be used alone or in combination of two or more.

The blending amount of at least one resin selected from the above rosin-based resins, terpene-based resins, petroleum-based resins, phenol-based resins, coal-based resins, and xylene-based resins used for the purpose of adjusting the adhesiveness further enhances the effect. From the standpoint of exhibiting it, it is preferably 0.05 to 20% by mass, more preferably 0.05 to 10% by mass, based on the total amount of the shaft.

Furthermore, in addition to the above-mentioned polypropylene-based resins and the like, other than the above-mentioned resins used for the purpose of adjusting the adhesiveness, if desired, a heat stabilizer, an antioxidant, a light stabilizer, an ultraviolet absorber, as long as the effect is not impaired. Crystal nucleating agents, anti-blocking agents, sealing improvers, release agents (e.g., stearic acid, silicon oil, etc.), lubricants such as polyethylene wax, coloring agents, pigments, inorganic fillers (e.g., alumina, talc, carbonate calcium, mica, wallastonite, clay, etc.), blowing agents (organic, inorganic), antibacterial agents (e.g. imidazole, phenol, silver, etc.) and flame retardants (e.g. hydrated metal compounds, red phosphorus, Optional components such as ammonium polyphosphate, antimony compounds, silicones, etc.) can be included in appropriate amounts. In addition, the shaft material may further contain alkylsulfonic acid phenyl ester and cyclohexanedicarboxylic acid ester. By including phenyl alkylsulfonate and cyclohexanedicarboxylate in the shaft, handwriting can be erased without damaging the paper surface and without blurring printed characters. Manufacture can be performed, for example, by a method such as extrusion molding or injection molding, using the above-mentioned polypropylene-based resin or the like.

When imparting durability, the tensile modulus (JIS K 7161: 2014-1) should be 70 MPa or more, preferably 80 to 5000 MPa, from the viewpoint of exhibiting the effect. If the tensile elastic modulus is less than 70 MPa, the effect cannot be exhibited, which is not preferable. In order to make the tensile modulus of this shaft 70 MPa or more, it can be adjusted by appropriately combining the type and compounding amount of the polypropylene resin to be used, other resin types, their content, and the like.

More preferably, the permanent elongation of the shaft (JIS K6273:2006) is 50% or more, particularly preferably 50 to 100%, in order to further exhibit the effect and reduce resistance. The “permanent elongation” defined here means that the stress is removed after the test piece is held at 23° C. for 6 hours in a double-stretched state. It refers to the value (%) obtained by dividing the stretched length by the length before stretching.

As described above, the refill 2 may be a refill containing thermochromic ink containing a thermochromic coloring material. In this case, the writing instrument 40 is a thermochromic writing instrument, and the writing instrument main body 41 may be a friction body as an erasing member. Handwriting by the writing instrument 40 can be thermally discolored by frictional heat or the like generated when the writing instrument main body 41, for example, the rear end portion of the writing instrument main body 41 or the tapered portion near the writing portion 42 is rubbed.

Here, the thermochromic ink maintains a predetermined color (first color) at room temperature (e.g., 25°C) and changes to another color (second color) when heated to a predetermined temperature (e.g., 60°C). , and then returns to the original color (first color) when cooled to a predetermined temperature (eg, −5° C.). In the double-headed writing instrument 1 using thermochromic ink, making the second color colorless and heating the drawn line drawn with the first color (for example, red) to make it colorless is referred to as "erasing" here. and Therefore, the writing surface or the like on which the drawn line is written is rubbed by the frictional body to generate frictional heat, thereby making the drawn line colorless, that is, erasing it. It should be noted that, as a matter of course, the second color may be colored other than colorless.

Thermochromic microcapsule pigments to be thermochromic coloring materials are those that change color due to heat such as frictional heat, for example, if they have the function of changing from colored to colorless, from colored to colored, from colorless to colored, etc. There are no particular restrictions, and various types can be used, including microencapsulated thermochromic compositions containing at least a leuco dye, a developer, and a color change temperature adjuster.

The leuco dye that can be used is not particularly limited as long as it is an electron-donating dye and functions as a color former. Specifically, from the viewpoint of obtaining an ink with excellent color development properties, triphenylmethane-based, spiropyran-based, fluoran-based, diphenylmethane-based, rhodamine lactam-based, indolylphthalide-based, leuco auramine-based, etc. ) or a mixture of two or more (hereinafter simply referred to as “at least one”).

Specifically, 6-(dimethylamino)-3,3-bis[4-(dimethylamino)phenyl]-1(3H)-isobenzofuranone, 3,3-bis(p-dimethylaminophenyl)-6 -dimethylaminophthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1 -ethyl-2-methylindol-3-yl)-4-azaphthalide, 1,3-dimethyl-6-diethylaminofluorane, 2-chloro-3-methyl-6-dimethylaminofluorane, 3-dibutylamino-6 -methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-xyridinofluorane, 2-(2-chloroanilino)-6- dibutylaminofluorane, 3,6-dimethoxyfluorane, 3,6-di-n-butoxyfluorane, 1,2-benz-6-diethylaminofluorane, 1,2-benz-6-dibutylaminofluorane, 1,2-benz-6-ethylisoamylaminofluorane, 2-methyl-6-(Np-tolyl-N-ethylamino)fluorane, 2-(N-phenyl-N--methylamino)-6- (Np-tolyl-N-ethylamino)fluorane, 2-(3′-trifluoromethylanilino)-6-diethylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 2-methyl-6- Cyclohexylaminofluorane, 3-di(n-butyl)amino-6-methoxy-7-anilinofluorane, 3,6-bis(diphenylamino)fluorane, methyl-3',6'-bisdiphenylaminofluorane , chloro-3′,6′-bisdiphenylaminofluorane, 3-methoxy-4-dodecoxystyrinoquinoline, and the like.

These leuco dyes have a lactone skeleton, a pyridine skeleton, a quinazoline skeleton, a bisquinazoline skeleton, or the like, and develop color by ring-opening of these skeletons (rings).

The developer that can be used is a component that has the ability to develop the color of the leuco dye. is mentioned.

Specifically, o-cresol, tertiary butyl catechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, hexafluorobisphenol, p -n-butyl hydroxybenzoate, n-octyl p-hydroxybenzoate, resorcinol, dodecyl gallate, 2,2-bis(4'-hydroxyphenyl)propane, 4,4-dihydroxydiphenylsulfone, 1,1-bis (4'-hydroxyphenyl)ethane, 2,2-bis(4'-hydroxy-3-methylphenyl)propane, bis(4-hydroxyphenyl)sulfide, 1-phenyl-1,1-bis(4'-hydroxy phenyl)ethane, 1,1-bis(4'-hydroxyphenyl)-3-methylbutane, 1,1-bis(4'-hydroxyphenyl)-2-methylpropane, 1,1-bis(4'-hydroxyphenyl ) n-hexane, 1,1-bis(4′-hydroxyphenyl)n-heptane, 1,1-bis(4′-hydroxyphenyl)n-octane, 1,1-bis(4′-hydroxyphenyl)n -nonane, 1,1-bis(4′-hydroxyphenyl)n-decane, 1,1-bis(4′-hydroxyphenyl)n-dodecane, 2,2-bis(4′-hydroxyphenyl)butane, 2 , 2-bis(4′-hydroxyphenyl)ethyl propionate, 2,2-bis(4′-hydroxyphenyl)-4-methylpentane, 2,2-bis(4′-hydroxyphenyl)hexafluoropropane, At least one of 2,2-bis(4′-hydroxyphenyl)n-heptane, 2,2-bis(4′-hydroxyphenyl)n-nonane and the like can be mentioned.

The amount of the developer to be used may be arbitrarily selected according to the desired color density, and is not particularly limited. It is preferable to select within the range of about 100 parts by mass.

The discoloration temperature control agent that can be used is a substance that controls the discoloration temperature in the coloration of the leuco dye and developer. Specific examples of discoloration temperature regulators that can be used include alcohols, esters, ketones, ethers, acid amides, azomethines, fatty acids, and hydrocarbons.

More specifically, bis(4-hydroxyphenyl)phenylmethane dicaprylate (C ₇ H ₁₅ ), bis(4-hydroxyphenyl)phenylmethane dilaurate (C ₁₁ H ₂₃ ), bis(4-hydroxyphenyl)phenyl methane dimyristate (C ₁₃ H ₂₇ ), bis(4-hydroxyphenyl)phenylethane dimyristate (C ₁₃ H ₂₇ ), bis(4-hydroxyphenyl)phenylmethane dipalmitate (C ₁₅ H ₃₀ ), bis At least one of (4-hydroxyphenyl)phenylmethane dibehenate (C ₂₁ H ₄₃ ), bis(4-hydroxyphenyl)phenylethylhexylidene dimyristate (C ₁₃ H ₂₇ ) and the like can be mentioned.

The amount of the discoloration temperature adjusting agent to be used may be appropriately selected depending on the desired hysteresis width and color density at the time of color development, and is not particularly limited, but is usually per 1 part by mass of the leuco dye. , about 1 to 100 parts by mass.

The thermochromic microcapsule pigment is obtained by microencapsulating a thermochromic composition containing at least the leuco dye, a developer, and a color change temperature adjuster so that the average particle size is 0.2 to 5 μm. can be manufactured. Microencapsulation methods include, for example, an interfacial polymerization method, an interfacial polycondensation method, an in situ polymerization method, an in-liquid curing coating method, a phase separation method from an aqueous solution, a phase separation method from an organic solvent, a melting dispersion cooling method, an air A suspension coating method, a spray lining method, and the like can be mentioned, and can be appropriately selected according to the application.

For example, in the phase separation method from an aqueous solution, a leuco dye, a developer, and a discoloration temperature adjusting agent are heated and melted, then added to an emulsifier solution, heated and stirred to disperse them in the form of oil droplets, and then, as a capsule film agent, Using a resin raw material, for example, an amino resin solution, an isocyanate resin solution, etc. are gradually added, followed by reaction, and after preparation, the dispersion is filtered to produce the desired thermochromic microcapsule pigment. be able to.

The contents of these leuco dye, color developer, and color change temperature adjuster vary depending on the type of leuco dye, color developer, and color change temperature adjuster used, the microencapsulation method, and the like. The weight ratio of the developer is 0.1 to 100 and the discoloration temperature regulator is 1 to 100. The mass ratio of the capsule film agent to the capsule content is 0.1 to 1.

The thermochromic microcapsule pigment can be obtained by appropriately combining the types and amounts of the leuco dye, developer, and color change temperature adjusting agent, so that the color development temperature of each color (e.g., color development at 0 ° C. or higher), the color disappearance temperature ( For example, it is possible to set a suitable temperature for discoloration at 50° C. or higher, and it is preferable that the color changes from color to colorless by heat such as frictional heat.

In the thermochromic microcapsule pigment, the wall film is preferably made of a urethane resin, a urea/urethane resin, an epoxy resin, or an amino resin in order to further improve drawing density, storage stability, and writability. Examples of urethane resins include compounds of isocyanate and polyol. Epoxy resins include, for example, compounds of epoxy resins and amines. Amino resins include melamine resins, urea resins, benzoguanamine resins, and the like. The thickness of the wall film of the microcapsule colorant is appropriately determined according to the required wall film strength and drawing density.

The average particle size of the thermochromic microcapsule pigment is good for colorability, color development, easy decolorization, stability, fluidity in ink, and suppresses adverse effects on writing, and photodiscoloration, which will be described later. From the viewpoint of compatibility with the microcapsule pigment, it is preferably 0.2 to 5 μm, more preferably 0.3 to 3 μm. The "average particle diameter" defined here is the value obtained by measuring the average particle diameter (50% diameter) with a particle size analyzer [Microtrac HRA9320-X100 (manufactured by Nikkiso Co., Ltd.)] (refractive index 1.8). is.

If the average particle size is less than 0.2 μm, a sufficient drawn line density cannot be obtained. Backing tends to occur, which is not preferable. Furthermore, the 90% diameter is 8 μm or less, preferably 6 μm or less. When particles having a large diameter are present in a certain proportion or more, the above-mentioned influence tends to become more pronounced. The microcapsule pigment having the average particle size range (0.2 to 5 μm) described above varies depending on the microencapsulation method. It can be prepared by appropriately combining conditions.

The specific gravity of the thermochromic microcapsule pigment ranges from 0.9 to 1.3, preferably from 1.0 to 1.2. If the specific gravity is outside this range, the dispersion stability of the microcapsule pigment tends to decrease. In addition, microcapsule pigments having a specific gravity exceeding 1.3 tend to cause ink back due to vibration.

In the water-based ink composition for writing instruments, in addition to the thermochromic microcapsule pigment, the balance is water as a solvent (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.), and for each writing instrument (ballpoint pen (for marking pens, etc.), water-soluble organic solvents, thickeners, lubricants, rust inhibitors, antiseptics, antibacterial agents, etc. can.

Examples of water-soluble organic solvents that can be used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, 3-butylene glycol, thiodiethylene glycol, and glycerin, ethylene glycol monomethyl ether, and diethylene glycol monomethyl. Ethers can be used singly or in combination.

Among these, it is preferable to use glycerin for the purpose of suppressing ink solidification in the writing area due to ink back, and the amount added is preferably 1 to 10% by mass based on the total amount of ink. It is presumed to have the effect of reducing the cohesive force with the ink component.

As a thickener that can be used, for example, at least one selected from the group consisting of synthetic polymers, cellulose and polysaccharides is preferable. Specifically, gum arabic, tragacanth gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, welan gum, succinoglycan, diutan gum, dextran, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, starch glycolic acid and its salt, propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, polyacrylic acid and its salt, carboxyvinyl polymer, polyethylene oxide, copolymer of vinyl acetate and polyvinylpyrrolidone, crosslinked acrylic acid polymer and Examples thereof include salts thereof, non-crosslinked acrylic acid polymers and salts thereof, styrene-acrylic acid copolymers and salts thereof.

Among these, it is preferable to use polysaccharides. Due to their rheological properties, polysaccharides tend to be less susceptible to fluidity due to vibration, and problems such as poor writing due to ink back are less likely to occur. Xanthan gum is particularly preferred because it has an excellent balance with other properties required for writing inks.

Examples of lubricants include fatty acid esters of polyhydric alcohols, sugar higher fatty acid esters, polyoxyalkylene higher fatty acid esters, alkyl phosphates, alkyl sulfonates of higher fatty acid amides, and alkyl allyl sulfones, which are also used as surface treatment agents for pigments. Acid salts, derivatives of polyalkylene glycol, fluorosurfactants, polyether-modified silicones, and the like. Examples of rust preventives include benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, saponins and the like. Examples of antiseptics or antibacterial agents include phenol, sodium omadine, sodium benzoate, and benzimidazole compounds.

Conventionally known methods can be employed for producing this water-based ink composition for writing instruments. It is obtained by blending and stirring and mixing with a stirrer such as a homomixer or a disper. Further, if necessary, coarse particles in the ink composition may be removed by filtration or centrifugation.

The viscosity of the water-based ink composition for writing instruments is preferably 500 to 2000 mPa·s at 25° C. and a shear rate of 3.83/s, and preferably 20 to 100 mPa·s at a shear rate of 383/s. By setting the viscosity within the above range, it is possible to obtain an ink having excellent writing properties and stability over time. Further, S = αD ⁿ (where 1>n>0) (S is shear stress (dyn/cm ² ), D is shear rate (s ^-1 ), α is non-Newtonian viscosity coefficient) The desired non-Newtonian viscosity index n is preferably 0.2 to 0.6. By setting the non-Newtonian viscosity index n to the above range in addition to the above viscosity range, it becomes possible to appropriately set the fluidity of the ink against vibration, and it becomes possible to prevent the occurrence of ink back.

The surface tension of the water-based ink composition for writing instruments is preferably 25-45 mN/m, more preferably 30-40 mN/m. Within this range, the wettability balance between the inside of the pen tip and the ink becomes appropriate, and it is possible to prevent the occurrence of ink back.

An ink follower may be positioned immediately behind the ink in the refill. The material constituting the follower can be composed of at least a non-volatile or hardly volatile organic solvent and a thickening agent. The nonvolatile or hardly volatile organic solvent used in the ink follower is used as the base oil of the ink follower, and for example, liquid paraffin is used. Mineral oil and chemical synthetic oil are used as liquid paraffin, and polybutene, poly α-olefin, ethylene α-olefin oligomer and the like can be used as chemical synthetic oil.

Specific mineral oils that can be used include, for example, commercially available Diana Process Oils NS-100, PW-32, PW-90, NR-68, and AH-58 (manufactured by Idemitsu Kosan Co., Ltd.).

Specific polybutenes that can be used include, for example, commercially available Nissan polybutene 200N, polybutene 30N, polybutene 10N, polybutene 5N, polybutene 3N, polybutene 015N, polybutene 06N, polybutene 0N (manufactured by NOF CORPORATION), and polybutene. HV-15 (manufactured by Nippon Petrochemical Co., Ltd.), 35R (manufactured by Idemitsu Kosan Co., Ltd.), and the like.

Specific polyα-olefins that can be used include, for example, commercially available barrel process oils P-26, P-46, P-56, P-150, P-350, P-1500, P-2200, (P-10000, P-37500) (manufactured by Matsumura Oil Co., Ltd.) and the like.

Specific ethylene α-olefin oligomers that can be used include, for example, commercially available Lucant HC-10, HC-20, HC-100, HC-150, (HC-600, HC-2000) (the above, Mitsui chemical company) and the like.

These nonvolatile or hardly volatile organic solvents can be used singly or in combination of two or more.

Examples of thickening agents used in ink followers include calcium salts of phosphoric acid esters, fine silica particles, block copolymers of polystyrene-polyethylene/butylene rubber-polystyrene, block copolymers of polystyrene-polyethylene/propylene rubber-polystyrene, and hydrogenated styrene. -butadiene rubber, styrene-ethylenebutylene-olefin crystal block copolymer, olefin crystal-ethylenebutylene-olefin crystal block copolymer, acetoalkoxyaluminum dialkylate, and the like, and one or more of these may be used.

Preferable commercial products of calcium salts of phosphoric acid esters that can be used include Crodax DP-301LA (manufactured by Croda Japan). Fine particle silica that can be used includes hydrophilic fine particle silica and hydrophobic fine particle silica, and preferred commercial products of hydrophilic silica include AEROSIL-300 and AEROSIL-380 (manufactured by Nippon Aerosil Co., Ltd.). Preferred commercial products of hydrophobic silica include AEROSIL-974D and AEROSIL-972 (manufactured by Nippon Aerosil Co., Ltd.).

Preferred commercial products of block copolymers of polystyrene-polyethylene/butylene rubber-polystyrene include Kraton GFG-1901X, Kraton GG-1650 (manufactured by Shell Japan Co., Ltd.), Septon 8007, Septon 8004 (manufactured by Kuraray Co., Ltd.), and the like. are mentioned. Preferred commercial products of block copolymers of polystyrene-polyethylene/propylene rubber-polystyrene include Kraton GG-1730 (manufactured by Shell Japan), Septon 2006 and Septon 2063 (manufactured by Kuraray Co., Ltd.).

Preferred commercially available hydrogenated styrene-butadiene rubbers include DYNARON1320P, DYNARON1321P (manufactured by JSR Corporation), Tuftec Hl041, Tuftec Hl141 (manufactured by Asahi Chemical Industry Co., Ltd.) and the like.

Preferable commercially available styrene-ethylenebutylene-olefin crystal block copolymers include DYNARON4600P (manufactured by JSR Corporation), etc. Preferable commercially available olefin crystal-ethylenebutylene-olefin crystal block copolymers include DYNARON6200P and DYNARON6201B ( manufactured by JSR) and the like.

Plenact AL-M (manufactured by Ajinomoto Fine-Techno Co., Ltd.) and the like can be mentioned as preferred commercial products of acetoalkoxyaluminum dialkylate.

Among these thickeners, thermoplastic olefin-based elastomers such as block copolymers of styrene-ethylenebutylene-olefin crystals and block copolymers of olefin crystals-ethylenebutylene-olefin crystals are preferably used from the viewpoint of further exerting the effect. .

Furthermore, in order to obtain an ink follower that prevents the occurrence of ink back, the average value of the tan δ values measured for each frequency while exponentially increasing in the frequency range of 1 to 63 rad/s should be 1.0 or more. is preferred, and 1.7 to 3.4 is more preferred.

Here, tan δ is a value that means loss elastic modulus/storage elastic modulus, and conventionally, the average value of tan δ values measured for each frequency while increasing exponentially in the frequency range “1 to 63 rad/s” is 1.0 or less is preferred. Here, by setting the average value of the tan δ values measured for each frequency at 1 to 63 rad/s to 1.0 or more, it is possible to absorb vibrations and prevent the occurrence of ink back.

1 writing instrument set 2 case 2
10 Case Body 11 Holding Protrusion 20 Cover Member 30 Slide Member 34 Second Engaging Part 40 Writing Tool 42 Writing Part 45 First Engaging Part 50 Clip Member 51 Spring

Claims (2)

A writing instrument set comprising a plurality of writing instruments and a case capable of accommodating the plurality of writing instruments in an aligned state,
A first engaging portion is provided on the writing portion side of the writing instrument, and a second engaging portion is provided inside the case,
By engaging or disengaging the first engaging portion and the second engaging portion, each of the writing instruments can be attached to and detached from the case ,
The writing instrument further comprises a slide member, wherein the second engaging portion is provided on the slide member, the case has an operation portion, and operation of the operation portion causes the slide member to move rearward to remove the writing instrument. A writing instrument set characterized by being in a state . A writing instrument set comprising a plurality of writing instruments and a case capable of accommodating the plurality of writing instruments in an aligned state,
A first engaging portion is provided on the writing portion side of the writing instrument, and a second engaging portion is provided inside the case,
By engaging or disengaging the first engaging portion and the second engaging portion, each of the writing instruments can be attached to and detached from the case,
The plurality of writing instruments includes a thermochromic writing instrument and a non-thermochromic writing instrument, wherein the flexural modulus of the writing instrument body of the thermochromic writing instrument and the flexural elasticity of the writing instrument body of the non-thermochromic writing instrument A writing instrument set characterized in that the modulus differs by 300 MPa or more.

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