Multi-core notebook

Abstract

To provide a multiple refill type writing instrument which can easily switch refills that write.SOLUTION: A multiple refill type writing instrument 1 includes a barrel 2, an operating member 20 which is provided to be movable in the front-rear direction with respect to the barrel 2, multiple refills 5 and a rotating member 30 which is provided to be able to rotate around the central axis with respect to the barrel 2 while holding the multiple refills 5, in which the operating member 20 and the rotating member 30 move harmoniously in response to the front-rear movements of the operating member 20 to rotate the rotating member 30, and as a result one of the multiple refills 5 moves forward.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention relates to a multi-core writing instrument. [Background technology]

[0002] Multi-core writing instruments equipped with multiple refills, allowing for the selective deployment and retraction of desired refills, are known (Patent Documents 1 and 2).

[0003] In the multi-core writing instrument described in Patent Document 1, multiple operating parts (sliding bodies) are arranged circumferentially on the side of the barrel. Each operating part is movable in the front-rear direction. Multiple refills are arranged inside the barrel, and each refill is connected to a corresponding operating part. By advancing the operating part corresponding to the desired refill, that refill can be put into writing mode. Therefore, when switching the refill to be written with during writing, first, writing is interrupted and the barrel is changed, then the position of the operating part corresponding to the desired refill is confirmed, and then the operating part is advanced.

[0004] In the multi-core writing instrument described in Patent Document 2, a window hole is formed in the part that the fingertip contacts when writing, and the operating shaft, which is the operating part, protrudes radially from the window hole. In the multi-core writing instrument described in Patent Document 2, two refills can be selectively extended and retracted. When switching from a non-writing state to a writing state, first, the operating shaft is rotated in the direction corresponding to the desired refill (let's call it the "first direction"), then the operating shaft is advanced, then the operating shaft is rotated in the first direction to engage with the locking part, and the writing state is set. Also, when switching the refill to be written with while writing, first, the operating shaft is rotated in the opposite direction to the first direction (let's call it the "second direction"), then the operating shaft is retracted, then it is rotated further in the second direction, then the operating shaft is advanced, then the operating shaft is rotated in the second direction to engage with the locking part, and the writing state is set. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-049192 [Patent Document 2] Japanese Patent Publication No. 2001-219690 [Overview of the project] [Problems that the invention aims to solve]

[0006] In the multi-core writing instrument described in Patent Document 1, each time a refill is to be switched, it is necessary to change the grip of the multi-core writing instrument, check the position of the operating part corresponding to the desired refill, and move the operating part forward, which is cumbersome. In the multi-core writing instrument described in Patent Document 2, when switching from a non-writing state to a writing state, and when switching the refill to be written on while in the writing state, complex finger movements are required, which are also cumbersome.

[0007] The present invention aims to provide a multi-core writing instrument that allows for easy switching of the refill used for writing. [Means for solving the problem]

[0008] According to one aspect of the present invention, a multi-core writing instrument is provided, comprising a barrel, a first operating part provided to be movable in the front-rear direction relative to the barrel, a plurality of writing elements, and a rotating member provided to be rotatable around a central axis relative to the barrel while holding the plurality of writing elements, wherein the first operating part and the rotating member cooperate to rotate the rotating member in response to the front-rear movement of the first operating part, causing one of the plurality of writing elements to move forward. In the axial direction of the multi-core writing instrument, the writing part side is defined as the "front" side, and the side opposite the writing part is defined as the "rear" side.

[0009] The writing instrument may further include a cam surface, such that one of the multiple writing elements moves forward as the multiple writing elements cooperate with the cam surface in response to the rotation of the rotating member. A cam groove may be formed on one of the first operating part and the rotating member, and a cam projection may be formed on the other of the first operating part and the rotating member, such that the cam groove and the cam projection cooperate to rotate the rotating member. The cam groove may be formed spirally around a central axis. The writing instrument may further include a second operating part, such that the advanced writing element moves in and out of the barrel by a knock operation that presses the second operating part forward. The first operating part or all or part of the second operating part may be an eraser capable of erasing the writing of the multi-core writing instrument. The first operating part may be located in the front half of the barrel. [Effects of the Invention]

[0010] According to aspects of the present invention, a common effect is to provide a multi-core writing instrument that allows for easy switching of the refill being used for writing. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a perspective view of a multi-core writing instrument according to an embodiment of the present invention. [Figure 2] Figure 2 is a longitudinal cross-sectional view of a multi-core writing instrument in a non-writing state. [Figure 3] Figure 3 is a longitudinal cross-sectional view of a multi-core writing instrument in the writing state. [Figure 4] Figure 4 is a vertical cross-sectional view of a multi-core writing instrument during refill switching while writing. [Figure 5] Figure 5 is a vertical cross-sectional view of a multi-core writing instrument after switching refills while in the writing state. [Figure 6] Figure 6 is a longitudinal cross-sectional view of the rear axis. [Figure 7] Figure 7 is a perspective view of the operating component. [Figure 8] Figure 8 is a side view of the operating component. [Figure 9]FIG. 9 is a perspective view of the rotating member. [Figure 10] FIG. 10 is a longitudinal sectional view of the rotating member. [Figure 11] FIG. 11 is a perspective view of the slide cam. [Figure 12] FIG. 12 is a longitudinal sectional view of the slide cam.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Throughout the drawings, corresponding components are denoted by common reference numerals.

[0013] FIG. 1 is a perspective view of the multi-core writing instrument 1 according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the multi-core writing instrument 1 in a non-writing state, FIG. 3 is a longitudinal sectional view of the multi-core writing instrument 1 in a writing state, FIG. 4 is a longitudinal sectional view of the multi-core writing instrument 1 during refill switching in the writing state, and FIG. 5 is a longitudinal sectional view of the multi-core writing instrument 1 in the writing state after refill switching.

[0014] The multi-core writing instrument 1 has a shaft cylinder 2 which is a cylindrical member formed in a cylindrical shape. The shaft cylinder 2 consists of a front shaft 3, a middle shaft 4, and a rear shaft 10. Further, inside the shaft cylinder 2, a plurality of refills 5, specifically two refills 5, are arranged as writing bodies each having a writing part 5a at one end. When distinguishing the two refills 5, they are referred to as refill 5A and refill 5B. Each of the two refills 5 is independently urged rearward by a corresponding spring 6 as an elastic member. The multi-core writing instrument 1 further has an operating member 20 which is a first operating part, a rotating member 30, a slide cam 40, a knock member 50 which is a second operating part, a rotor 60, and a sliding piece 70. In this specification, in the axial direction of the multi-core writing instrument 1, the side of the writing part 5a is defined as the "front" side, and the side opposite to the writing part 5a is defined as the "rear" side. Unless otherwise specified, the central axis or the axial direction refers to the central axis or the axial direction of the multi-core writing instrument 1.

[0015] The multi-core writing instrument 1 is a click-type writing instrument in which the refill 5 extends and retracts relative to the barrel 2 by a click operation in which the click member 50 is pressed forward. That is, by a click operation in which the click member 50 is pressed forward, the refill 5, which is relatively advanced, specifically the refill 5A in Figure 2, extends and retracts relative to the end face of the barrel 2.

[0016] Generally, retractable writing instruments have a rotor. The outer surface of the rotor is provided with a protruding cam, and the inner surface of the barrel is provided with a protruding cam that works in cooperation with the rotor's cam. By pressing the button, the cam of the rotor and the cam of the barrel are locked or unlocked, thereby switching between the writing state and the non-writing state.

[0017] In this embodiment, a cam portion 11, described later, is formed on the inner circumferential surface of the rear end of the rear shaft 10 of the barrel 2. The knocking operation is performed by pressing the knocking member 50 forward, thereby moving the rotor 60 forward to a predetermined position within the barrel 2 together with the knocking member 50. That is, in order for the cam portion (not shown) of the rotor 60 to engage with the cam portion 11 of the barrel 2, the rotor 60 is moved to a predetermined position where the rear end surface of the cam portion of the rotor 60 is positioned at least axially forward of the front end surface of the cam portion 11 of the barrel 2. After moving the rotor 60 to the predetermined position, when the force applied to the knocking member 50 is released, the rotor 60 rotates slightly backward due to the biasing force of the spring 6, and the rear end surface of the cam portion of the rotor 60 engages with the front end surface of the cam portion 11 of the barrel 2, and the multi-core writing instrument 1 enters the writing state (Figure 3).

[0018] In the writing state, when the knocking mechanism is pressed forward by the knocking operation, the rotor 60 is moved forward again to its predetermined position. This releases the lock between the rear end surface of the cam portion of the rotor 60 and the front end surface of the cam portion 11 of the barrel 2, causing the rotor 60 to rotate. Subsequently, when the force applied to the knocking mechanism 50 is released, the rotor 60 moves further rearward due to the biasing force of the spring 6, and the multi-core writing instrument 1 returns to a non-writing state (Figure 2).

[0019] The configuration of the main components will be explained with reference to Figures 6 through 11 as appropriate.

[0020] Figure 6 is a longitudinal cross-sectional view of the rear shaft 10. In the assembled state of the multi-core writing instrument 1, the rear shaft 10 is positioned such that its upper side is the rear side of the multi-core writing instrument 1 in Figure 6. The rear shaft 10 is a cylindrical member formed in a cylindrical shape. Rectangular grooves are formed on the front end surface of the rear shaft 10. The grooves on the front end surface of the rear shaft 10 fit together and are joined with grooves (Figure 1) that are complementaryly formed on the rear end surface of the central shaft 4. A cam portion 11 is formed on the inner circumferential surface of the rear end of the rear shaft 10. The cam portion 11 consists of a plurality of projections 12 extending in the axial direction, and as described above, it engages with or disengages from the cam portion of the rotor 60 during the knocking operation. Two slide grooves 13 are formed on the inner circumferential surface of the rear shaft 10, extending from the front end toward the rear and arranged opposite each other. The inner circumferential surface of the rear axle 10 behind the front end is formed with a smaller diameter than the inner circumferential surface of the front end, and a forward-facing annular first step portion 14 is formed therein. In addition, a forward-facing annular second step portion 15 is formed on the inner circumferential surface in front of the cam portion 11. A first through hole 16a is formed on the front side of the circumferential surface of the rear axle 10 along the axial direction, and a second through hole 16b is formed on the rear side.

[0021] Figure 7 is a perspective view of the operating member 20, and Figure 8 is a side view of the operating member 20. In the assembled state of the multi-core writing instrument 1, the operating member 20 is positioned such that its upper side is the rear side of the multi-core writing instrument 1 in Figures 7 and 8. The operating member 20 is a cylindrical member formed in a cylindrical shape. An operating projection 21 is formed on the outer circumferential surface of the front end of the operating member 20. Two slits 22 are formed on both sides of the operating projection 21 in the circumferential direction of the operating member 20, extending parallel to each other from the front end toward the rear. A cam groove 23 is formed spirally around the central axis on the circumferential surface of the operating member 20. The spiral cam groove 23 is formed for approximately half a rotation clockwise from near the rear end toward the front when the operating member 20 is viewed from the rear. A single slit 24 is formed on the circumferential surface of the operating member 20, extending toward the front from the rear end.

[0022] Figure 9 is a perspective view of the rotating member 30, and Figure 10 is a longitudinal cross-sectional view of the rotating member 30. In the assembled state of the multi-core writing instrument 1, the rotating member 30 is positioned such that its upper side is the rear side of the multi-core writing instrument 1 in Figures 9 and 10. The rotating member 30 consists of a cylindrical small-diameter portion 31 located at the front, a cylindrical large-diameter portion 32 formed behind the small-diameter portion 31, and a cylindrical sliding portion 33 formed behind the large-diameter portion 32. A cam projection 34 is formed on the outer circumferential surface of the small-diameter portion 31. The cross-sectional shape of the cam projection 34 is elliptical or a rounded rectangle. The cam projection 34 is oriented along the extending direction of the cam groove 23, which will be arranged as described later. The cam projection 34 may also be circular. The interiors of the large-diameter portion 32 and the sliding portion 33 are equally separated by a partition wall 35 extending in the axial direction in order to position each of the two refills 5 spaced apart. Furthermore, two insertion holes 36 extending in the axial direction are formed inside the large-diameter portion 32 at symmetrical positions on either side of the partition wall 35. A rearward-facing support surface 37 is formed on the inner circumferential surface of each insertion hole 36. Two rectangular through holes, known as rail grooves 38, extending in the axial direction are formed on the circumferential surface of the sliding portion 33 at symmetrical positions on either side of the partition wall 35.

[0023] Figure 11 is a perspective view of the slide cam 40, and Figure 12 is a longitudinal cross-sectional view of the slide cam 40. In the assembled state of the multi-core writing instrument 1, the slide cam 40 is positioned such that its upper side is the rear side of the multi-core writing instrument 1 in Figure 11. The slide cam 40 has an annular portion 41 formed in an annular shape around the central axis and a claw-shaped claw portion 42. The edge of the claw portion 42 has a flat surface 43 and an obliquely shaped oblique end surface 44. The flat surface 43 and oblique end surface 44 of the claw portion 42 and the front end surface 45 of the annular portion 41 constitute the cam surface 46. Two slide protrusions 47 extending in the axial direction are formed on the outer circumferential surface of the annular portion 41. The two slide protrusions 47 are formed symmetrically around the central axis. The inner circumferential surface near the rear end of the annular portion 41 protrudes in an annular shape, thereby forming an annular support surface 48 facing rear.

[0024] Next, the combination and arrangement of each component in the multi-core writing instrument 1 will be explained, mainly with reference to Figures 1 to 5.

[0025] The front shaft 3 is fitted to the front end of the central shaft 4. The rotating member 30 is positioned inside the shaft cylinder 2 such that the front end surface of the small-diameter portion 31 faces the rear end surface of the front shaft 3, and the rear end surface of the large-diameter portion 32 of the rotating member 30 faces the first stage portion 14 of the rear shaft 10. In this way, the rotating member 30 is positioned inside the shaft cylinder 2 so that it can rotate around the central axis while its movement in the axial direction is restricted. The rear part of the front shaft 3 is formed in a cylindrical shape having substantially the same outer and inner diameters as the small-diameter portion 32 of the rotating member 30. The operating member 20 is positioned across both the outer surface of the rear part of the front shaft 3 and the outer surface of the small-diameter portion 32 of the rotating member 30. At this time, the cam projection 34 of the rotating member 30 is positioned inside the cam groove 23 of the operating member 20. In addition, the operating projection 21 of the operating member 20 protrudes to the outside of the shaft cylinder 2 through a window hole 4a formed on the circumferential surface of the central shaft 4. The window hole 4a is a rectangular through hole extending in the axial direction. The operating projection 21 contacts the inner edge of the window hole 4a, thereby restricting the forward and backward movement of the operating member 20 to a predetermined distance and restricting its rotation around its central axis. When the operating member 20 is placed inside the shaft cylinder 2, the slits 22 and 24 formed in the operating member 20 allow for radial elastic deformation, making it easy to place.

[0026] Each of the two refills 5 is inserted into a corresponding insertion hole 36 of the rotating member 30 and separated by a partition wall 35. A sliding saddle 70 is inserted into the rear end of each refill 5 and is connected to the refill 5 by fitting. The sliding saddle 70 connected to the refill 5 fits into a rail groove 38 of the rotating member 30 and is positioned to slide axially without falling out. The rear end of the sliding portion 33 of the rotating member 30 is received at the front of the slide cam 40. Each of the sliding projections 47 of the slide cam 40 is positioned in a corresponding slide groove 13 of the rear shaft 10. Thus, the slide cam 40 is positioned to slide axially without rotating around the central axis.

[0027] The spring 6 is positioned within the insertion hole 36 of the rotating member 30. At this time, the front end of the spring 6 is supported by the support surface 37 of the rotating member 30, and the rear end of the spring 6 is in contact with the sliding ring 70. As a result, the spring 6 biases the sliding ring 70 backward, and consequently biases the refill 5 connected to the sliding ring 70 backward. In addition, the rear end of the sliding ring 70 is in contact with the cam surface 46 of the slide cam 40. Therefore, the spring 6 also biases the slide cam 40 backward via the sliding ring 70. In the non-writing state of the multi-core writing instrument 1 (Figure 2), the backward movement of the backward-biased slide cam 40 is restricted by the support surface 48 of the slide cam 40 contacting the front end surface of the rotor 60, or by the rear end surface of the slide cam 40 contacting the second stage portion 15 of the rear shaft 10. Furthermore, in the writing state of the multi-core writing instrument 1 (Figure 3), the rearward movement of the rearward-biased slide cam 40 is restricted by the contact between the support surface 48 of the slide cam 40 and the front end surface of the rotor 60.

[0028] Next, we will explain the operation of the multi-core writing instrument 1.

[0029] In the multi-core writing instrument 1, as described above, the first operating part, the operating member 20, specifically the operating projection 21, is provided so as to be movable in the front-rear direction relative to the barrel 2. The multi-core writing instrument 1 is configured such that, in response to the front-rear movement of the operating member 20, the operating member 20 and the rotating member 30 cooperate to rotate the rotating member 30, thereby causing one of the multiple refills 5 to move forward. That is, the front-rear movement of the operating member 20 is converted into rotational motion of the rotating member 30, and the rotational motion of the rotating member 30 is converted into front-rear movement of the refill 5.

[0030] In the states shown in Figures 2 and 3, refill 5A is in a more advanced position than refill 5B. That is, the sliding ring 70 to which refill 5A is connected is positioned on the flat surface 43 of the claw portion 42 on the cam surface 46 of the slide cam 40. On the other hand, the sliding ring 70 to which refill 5B is connected is positioned on the front end surface 45 of the annular portion 41 on the cam surface 46 of the slide cam 40. Therefore, refill 5A is relatively further forward than refill 5B. Consequently, in the non-writing state shown in Figure 2, when the knock member 50, which is the second operating part, is knocked, refills 5A and 5B move forward together with the rotor 60 and the slide cam 40. As a result, only the relatively advanced refill 5A protrudes from the barrel 2, and the writing state is achieved (Figure 3). Note that the operating member 20 and the rotating member 30 do not move in the axial direction as a result of the knock operation.

[0031] In the state shown in Figure 3, the operating projection 21 of the operating member 20 is positioned at the front end of the window hole 4a, and the cam projection 34 of the rotating member 30 is positioned at the rear end of the cam groove 23 of the operating member 20. In this state, when the operating projection 21 of the operating member 20 is moved backward, the cam projection 34 moves relatively forward along the helical trajectory of the cam groove 23. As a result, the rotating member 30 rotates around the central axis (Figure 4). At this time, the refill 5 and the sliding piece 70 rotate together with the rotating member 30 around the central axis while being biased backward by the spring 6. As a result, each of the sliding pieces 70 moves circumferentially along the cam surface 46 of the slide cam 40. Therefore, the sliding piece 70 to which the refill 5A is connected moves from the flat surface 43 of the claw portion 42 along the inclined end surface 44 toward the front end surface 45 of the annular portion 41 on the cam surface 46 of the slide cam 40. On the other hand, the sliding ring 70 to which the refill 5B is connected moves along the cam surface 46 of the slide cam 40 from the front end surface 45 of the annular portion 41 along the inclined end surface 44 toward the flat surface 43 of the claw portion 42.

[0032] When the operating projection 21 of the operating member 20 is moved further rearward to its rear end within the window hole 4a, the cam projection 34 of the rotating member 30 reaches its front end within the cam groove 23 of the operating member 20. This completes the rotation of the rotating member 30 around its central axis, specifically a 180-degree rotation. That is, the sliding piece 70 to which refill 5A is connected is positioned on the front end surface 45 of the annular portion 41 on the cam surface 46 of the slide cam 40. On the other hand, the sliding piece 70 to which refill 5B is connected is positioned on the flat surface 43 of the claw portion 42 on the cam surface 46 of the slide cam 40. Therefore, refill 5B moves forward relative to refill 5A and protrudes from the barrel 2, entering the writing state (Figure 5).

[0033] In the state shown in Figure 5, to write again with refill 5A, the operating projection 21 of the operating member 20 is moved forward. Moving the operating projection 21 backward causes the cam projection 34 to move relatively backward along the helical trajectory of the cam groove 23. As a result, the rotating member 30 rotates around the central axis in the opposite direction to before (Figure 4). Consequently, refill 5A moves forward relative to refill 5B and protrudes from the barrel 2, entering the writing state (Figure 3). Although the switching of refills 5 in the writing state of the multi-core writing instrument 1 has been explained with reference to Figures 3 to 5, the switching of refills 5 can also be performed in the non-writing state of the multi-core writing instrument 1 in the same manner.

[0034] Next, a detailed explanation will be given regarding the operation of the multi-core writing instrument 1 by the user. Normally, the user holds the central shaft 4 of the multi-core writing instrument 1 with their thumb, index finger, and middle finger while writing. At this time, the multi-core writing instrument 1 is held so that the operating projection 21 of the operating member 20 is positioned between the thumb and index finger. To switch refills, the user supports the multi-core writing instrument 1 with their index and middle fingers while using their thumb to slide or flick the operating projection 21 forward or backward. Afterward, the user returns their thumb to its original position and grips the multi-core writing instrument 1 again, allowing them to write.

[0035] Therefore, with the multi-core writing instrument 1, the refill being used for writing can be easily switched. In particular, it is preferable that the first operating part, i.e., the operating member 20 or operating projection 21, is located on the front half of the barrel 2 to facilitate operation with the thumb. Furthermore, with the multi-core writing instrument 1, the refill being used for writing can be switched without interrupting writing or changing the grip of the barrel 2. Moreover, the user can easily determine which of refills 5A and 5B is in the advanced position by looking at or touching the position of the operating projection 21 within the window hole 4a.

[0036] Furthermore, the user can determine which of the refills 5A and 5B is in the advanced position by checking the inside of the barrel 2 through the first through-hole 16a and second through-hole 16b formed in the rear shaft 10. For this purpose, a sliding wheel 70 colored with the same color as the ink contained in the connected refill 5 is used. For example, in the state shown in Figure 2, the sliding wheel 70 of refill 5A is visible through the first through-hole 16a and second through-hole 16b. Therefore, the user can determine that if they perform the knock operation in this state, refill 5A will protrude from the barrel 2. Also, in the writing state shown in Figure 3, the sliding wheel 70 of refill 5A is visible only through the first through-hole 16a. Therefore, the user can determine that refill 5A is protruding from the barrel 2. On the other hand, in the state shown in Figure 5, the sliding wheel 70 of refill 5B is visible only through the first through-hole 16a. Therefore, the user can determine that the refill 5B protrudes from the barrel 2.

[0037] In the embodiment described above, the multi-core writing instrument 1 was a click-type writing instrument, but it may also be configured as a writing instrument that allows switching of the refill 5 protruding from the barrel 2 without performing a click operation. That is, the click member 50 and rotor 60 are eliminated in the multi-core writing instrument 1, and the slide cam 40 is fixed at the position shown in Figures 3 to 5. In this case, the slide cam 40 may be formed integrally with the barrel 2. In the multi-core writing instrument configured in this way, as shown in Figure 4, if the operating projection 21 is positioned at an intermediate position in the front-rear direction of the window hole 4a, the multi-core writing instrument can be put into a non-writing state. From this state, by moving the operating projection 21 forward, the refill 5A can be made to protrude from the barrel 2, and by moving the operating projection 21 backward, the refill 5B can be made to protrude from the barrel 2, thereby putting the multi-core writing instrument into a writing state.

[0038] Furthermore, in the above-described embodiment, a cam groove 23 was formed on the operating member 20 and a cam projection 34 was formed on the rotating member 30. However, a cam projection projecting radially inward may be formed on the operating member and a cam groove on the rotating member. In other words, any configuration can be adopted as long as a cam groove is formed on one of the first operating part and the rotating member, and a cam projection is formed on the other of the first operating part and the rotating member, and the first operating part and the rotating member cooperate through the cooperation of the cam groove and the cam projection. Also, the shape of the cam groove can be any configuration as long as the forward and backward movement of the first operating part is converted into rotational movement of the rotating member.

[0039] Furthermore, in the embodiment described above, the multi-core writing instrument 1 had two refills 5, but it may have three or more refills. Depending on the number of refills, the number of insertion holes in the rotating member, the shape of the partition wall, and the shape of the cam surface of the slide cam can be arbitrarily configured. That is, the position and shape of the claw portion of the cam surface of the slide cam can be configured such that, in response to the rotation of the rotating member, the cam surface and the multiple refills cooperate to cause one of the multiple refills to move forward. In this case, the position of the operating projection and the protruding refill, i.e., the position of the cam projection in the cam groove and the protruding refill, are in a corresponding relationship. In the embodiment described above, since there were two refills, when the operating projection 21 was at the front end and rear end of the window hole 4a, one of the refills was configured to protrude from the barrel 2. For example, if there are three refills, it is possible to configure it so that when the operating projection 21 is at the front end, the middle, and the rear end of the window hole 4a, one of the three refills protrudes.

[0040] The refill 5 described above may be a ballpoint pen refill, or it may be another type of refill such as a mechanical pencil, marking pen, stylus, eraser, or friction element. Furthermore, the operating member 20, which is the first operating part, may be made into an erasing member for erasing writing by the refill 5 by bonding or two-color molding to the entire operating member 20 or a part of the operating member 20. Furthermore, the knocking member 50, which is the second operating part, may be made into an erasing member for erasing writing by the refill 5 by bonding or two-color molding to the entire knocking member 50 or a part of the knocking member 50. In addition, other parts of the multi-core writing instrument 1, such as the front end of the front barrel 3, may be used as the erasing member.

[0041] The refill can also be a ballpoint pen containing thermochromic ink, a mechanical pencil containing a thermochromic lead, etc. In this case, the multi-core writing instrument 1 is a thermochromic writing instrument, and the writing can be thermochromic due to the frictional heat generated when it is rubbed with the friction element, which is the erasing element. Here, thermochromic ink refers to ink that maintains a predetermined color (first color) at room temperature (e.g., 25°C), changes to a different 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 (e.g., -5°C). In a writing instrument using thermochromic ink, the second color is made colorless, and the process of heating the line written with the first color (e.g., red) to make it colorless is referred to here as "erasing". Therefore, the friction element acting as the erasing part rubs against the writing surface on which the lines are written, generating frictional heat, which in turn changes the lines to colorless, i.e., erases them. Of course, the second color mentioned above may be a color other than colorless.

[0042] The thermochromic microcapsule pigments used as thermochromic colorants are not particularly limited and can be used as long as they change color due to heat such as frictional heat, for example, as long as they have the function of changing from colored to colorless, colored to colored, or colorless to colored. Examples include a thermochromic composition containing at least a leuco dye, a developer, and a color change temperature adjuster, which is then microencapsulated.

[0043] The leuco dyes that can be used are not particularly limited, as long as they are electron-donating dyes that function as colorants. Specifically, from the viewpoint of obtaining an ink with excellent color development characteristics, conventionally known dyes such as triphenylmethane-based, spiropyran-based, fluorane-based, diphenylmethane-based, rhodamine lactam-based, indolylphthalide-based, and leucoauramine-based dyes can be used individually (one type) or in combination of two or more types (hereinafter simply referred to as "at least one type").

[0044] 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-methylindole-3-yl)phthalide, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindole-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-xylidinofluorane, 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-diethylamino Examples include nofluorane, 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, and 3-methoxy-4-dodecoxystylinoquinoline.

[0045] These leuco dyes possess structures such as lactone, pyridine, quinazoline, and bisquinazoline skeletons, and their color is produced when these skeletons (rings) open.

[0046] The color developers that can be used are components that have the ability to produce color in the above-mentioned leuco dyes, and examples include phenolic resin compounds, salicylic acid-based metal chlorides, salicylic acid resin-based metal salt compounds, and solid acid compounds.

[0047] Specifically, o-cresol, tert-butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, hexafluorobisphenol, n-butyl p-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'-Hydroxyphenyl)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 Examples include at least one of the following: 1-bis(4'-hydroxyphenyl)n-dodecane, 2,2-bis(4'-hydroxyphenyl)butane, 2,2-bis(4'-hydroxyphenyl)ethylpropionate, 2,2-bis(4'-hydroxyphenyl)-4-methylpentane, 2,2-bis(4'-hydroxyphenyl)hexafluoropropane, 2,2-bis(4'-hydroxyphenyl)n-heptane, and 2,2-bis(4'-hydroxyphenyl)n-nonane.

[0048] The amount of the color former used may be arbitrarily selected according to the desired color density and is not particularly limited. Usually, it is preferably selected within the range of about 0.1 to 100 parts by mass with respect to 1 part by mass of the above-mentioned leuco dye.

[0049] The discoloration temperature regulator that can be used is a substance that controls the discoloration temperature in the color development of the above leuco dye and color former. Conventionally known discoloration temperature regulators can be used. Specifically, alcohols, esters, ketones, ethers, acid amides, azomethines, fatty acids, hydrocarbons, etc. can be mentioned.

[0050] More specifically, bis(4-hydroxyphenyl)phenylmethane dicaprylate (C7H 15 ), bis(4-hydroxyphenyl)phenylmethane dilaurate (C 11 H 23 ), bis(4-hydroxyphenyl)phenylmethane dimyristate (C 13 H 27 ), bis(4-hydroxyphenyl)phenyl ethane dimyristate (C 13 H 27 ), bis(4-hydroxyphenyl)phenylmethane dipalmitate (C 15 H 30 ), bis(4-hydroxyphenyl)phenylmethane dibehenate (C 21 H 43 ), bis(4-hydroxyphenyl)phenyl ethyl hexylidene dimyristate (C 13 H 27 ), etc. at least one kind can be mentioned.

[0051] The amount of this discoloration temperature regulator used may be appropriately selected according to the desired hysteresis width, color density at the time of color development, etc. and is not particularly limited. Usually, it is preferably used within the range of about 1 to 100 parts by mass with respect to 1 part by mass of the leuco dye.

[0052] Thermochromic microencapsulated pigments can be produced by microencapsulating a thermochromic composition containing at least the above-mentioned leuco dye, developer, and temperature adjustment agent, such that the average particle size is 0.2 to 5 μm. Examples of microencapsulation methods include interfacial polymerization, interfacial polycondensation, insitu polymerization, liquid curing coating, phase separation from aqueous solutions, phase separation from organic solvents, melt-dispersion-cooling, air suspension coating, and spray drying, and can be appropriately selected depending on the application.

[0053] For example, in a phase separation method from an aqueous solution, a leuco dye, a color developer, and a color change temperature regulator are heated and melted, then added to an emulsifier solution, heated and stirred to disperse them into oil droplets, and then a resin raw material such as an amino resin solution or an isocyanate resin solution is gradually added as a capsule membrane agent, and the reaction is continued to prepare the solution. After this dispersion is filtered, the desired thermochromic microcapsule pigment can be produced.

[0054] The content of these leuco dyes, developers, and color change temperature regulators varies depending on the type of leuco dye, developer, and color change temperature regulator used, as well as the microencapsulation method. However, for every 1 unit of dye, the mass ratio is 0.1 to 100 units of developer and 1 to 100 units of color change temperature regulator. In addition, the mass ratio of the capsule membrane to the capsule contents is 0.1 to 1 unit.

[0055] The thermochromic microcapsule pigments can be configured to set the color development temperature (e.g., color development at 0°C or above) and decolorization temperature (e.g., decolorization at 50°C or above) of each color to suitable temperatures by appropriately combining the types and amounts of the leuco dye, developer, and color change temperature adjuster mentioned above. Preferably, the pigment changes from colored to colorless due to heat such as frictional heat.

[0056] In thermochromic microcapsule pigments, it is preferable that the wall film be formed of urethane resin, urea / urethane resin, epoxy resin, or amino resin, in order to further improve line density, storage stability, and writing performance. Examples of urethane resins include compounds of isocyanate and polyol. Examples of epoxy resins include compounds of epoxy resin and amine. Examples of amino resins include melamine resin, urea resin, and benzoguanamine resin. The thickness of the wall film of the microcapsule pigment is appropriately determined according to the required wall film strength and line density.

[0057] The average particle size of the thermochromic microcapsule pigment is preferably 0.2 to 5 μm, and more preferably 0.3 to 3 μm, from the standpoint of colorability, color development, ease of decolorization, stability, fluidity in ink, and suppression of adverse effects on writing performance, as well as compatibility with the photochromic microcapsule pigment described later. The "average particle size" defined here is the value obtained by measuring the average particle size (50% diameter) using a particle size analyzer [Microtrac HRA9320-X100 (manufactured by Nikkiso Co., Ltd.)] (refractive index 1.8).

[0058] If the average particle size is less than 0.2 μm, sufficient line density cannot be obtained. On the other hand, if it exceeds 5 μm, it is undesirable because it leads to deterioration of writing performance, a decrease in the dispersion stability of the thermochromic microcapsule pigment, and an increased likelihood of ink backflow due to vibration. Furthermore, the 90% diameter should be 8 μm or less, preferably 6 μm or less. If a certain proportion or more of larger particles are present, the above-mentioned effects tend to become more pronounced. Note that the microcapsule pigment with an average particle size within the above-mentioned range (0.2 to 5 μm) varies depending on the microencapsulation method, but in methods such as phase separation from aqueous solutions, it can be prepared by suitably combining the stirring conditions when producing the microcapsule pigment.

[0059] The specific gravity of the thermochromic microcapsule pigment is in the range of 0.9 to 1.3, preferably 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 with a specific gravity exceeding 1.3 are prone to ink backing due to vibration.

[0060] In an aqueous ink composition for writing instruments, in addition to the above-mentioned thermochromic microcapsule pigment, the remainder may include, as appropriate, water as a solvent (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.), and, depending on the application for each writing instrument (for ballpoint pens, marking pens, etc.), water-soluble organic solvents, thickeners, lubricants, rust inhibitors, preservatives, or antibacterial agents, to the extent that the effect is not impaired.

[0061] 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, as well as ethylene glycol monomethyl ether and diethylene glycol monomethyl ether, which can be used alone or in combination.

[0062] Of these, glycerin is preferably used to suppress ink solidification in the writing area due to ink backing, and the amount added is preferably 1 to 10% by mass of the total ink volume. The mechanism of action of glycerin is unknown, but it is presumed to have the effect of reducing the cohesive force between the pigment and ink components in the dry state.

[0063] As thickeners that can be used, at least one selected from the group consisting of synthetic polymers, cellulose, and polysaccharides is preferred. Specifically, examples include gum arabic, tragacanth gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, gelan gum, succinoglycan, dieutan gum, dextran, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, starch glycolic acid and its salts, propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, polyacrylic acid and its salts, carboxyvinyl polymer, polyethylene hydroxide, copolymer of vinyl acetate and polyvinylpyrrolidone, crosslinked acrylic acid polymer and its salts, non-crosslinked acrylic acid polymer and its salts, styrene acrylic acid copolymer and its salts, and the like.

[0064] Of these, polysaccharides are preferred. Due to their rheological properties, polysaccharides tend to be less affected by vibrations in terms of fluidity, and problems such as poor writing due to ink backflow are less likely to occur. Xanthan gum, in particular, is preferred because it has an excellent balance with other properties required for writing instrument inks.

[0065] Lubricants include fatty acid esters of polyhydric alcohols, which are also used as surface treatment agents for pigments; higher fatty acid esters of sugars; higher polyoxyalkylene fatty acid esters; alkyl phosphate esters; alkyl sulfonates of higher fatty acid amides; alkyl allyl sulfonates; derivatives of polyalkylene glycols; fluorinated surfactants; and polyether-modified silicones. Rust inhibitors include benzotriazole, tolyltriazole, dicyclohexylammonium nitride, and saponins. Preservatives or antibacterial agents include phenol, sodium omazine, sodium benzoate, and benzimidazole compounds.

[0066] Conventional methods can be used to produce this aqueous ink composition for writing instruments. For example, it can be obtained by blending predetermined amounts of the above-mentioned thermochromic and photochromic microcapsule pigments, as well as each component in the aqueous solution, and stirring and mixing them using a stirrer such as a homomixer or disper. Furthermore, if necessary, coarse particles in the ink composition may be removed by filtration or centrifugation.

[0067] The viscosity of the aqueous ink composition for writing instruments is preferably 500 to 2000 mPa·s at 25°C and a shear rate of 3.83 / s, and 20 to 100 mPa·s at a shear rate of 383 / s. By setting the viscosity within the above range, an ink with excellent writing properties and long-term stability can be obtained. Furthermore, S=αD n (However, 1>n>0) (S is shear stress (dyn / cm) 2 ), D is the shear rate (s -1 It is preferable that the non-Newtonian viscosity index n, which can be determined by the viscosity formula (where α is the non-Newtonian viscosity coefficient), is between 0.2 and 0.6. By setting the non-Newtonian viscosity index n within the above range in addition to the viscosity range, it becomes possible to appropriately set the fluidity of the ink in response to vibration, thereby preventing ink backflow.

[0068] The surface tension of the water-based ink composition for writing instruments is preferably 25 to 45 mN / m, and more preferably 30 to 40 mN / m. Within this range, the balance between the wettability of the inside of the pen tip and the ink is appropriate, making it possible to prevent ink backflow.

[0069] Within the refill, an ink follower may be placed immediately behind the ink. The materials constituting the follower can consist of at least a non-volatile or low-volatile organic solvent and a thickener. The non-volatile or low-volatile organic solvent used in the ink follower is used as the base oil of the ink follower, and for example, liquid paraffin can be used. Mineral oil and chemically synthesized oil can be used as liquid paraffin, and as chemically synthesized oil, polybutene, poly-α-olefin, ethylene-α-olefin oligomer, etc. can be used.

[0070] Examples of mineral oils that can be used include commercially available Diana Process Oil NS-100, PW-32, PW-90, NR-68, and AH-58 (manufactured by Idemitsu Kosan Co., Ltd.).

[0071] Specific examples of polybutenes that can be used include commercially available products such as Nissan Polybutene 200N, Polybutene 30N, Polybutene 10N, Polybutene 5N, Polybutene 3N, Polybutene 015N, Polybutene 06N, Polybutene 0N (all manufactured by Nippon Oil & Fats Co., Ltd.), Polybutene HV-15 (manufactured by Nippon Petrochemical Co., Ltd.), and 35R (manufactured by Idemitsu Kosan Co., Ltd.).

[0072] Specific examples of poly-α-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.).

[0073] Specific ethylene α-olefin oligomers that can be used include, for example, commercially available products such as Lucant HC-10, HC-20, HC-100, HC-150, (HC-600, HC-2000) (all manufactured by Mitsui Chemicals, Inc.).

[0074] These non-volatile or low-volatility organic solvents can be used individually or in combination of two or more.

[0075] Examples of thickeners used in ink-following bodies include calcium salts of phosphate esters, fine silica particles, polystyrene-polyethylene / butylene rubber-polystyrene block copolymers, polystyrene-polyethylene / propylene rubber-polystyrene block copolymers, hydrogenated styrene-butadiene rubber, styrene-ethylenebutylene-olefin crystal block copolymers, olefin crystal-ethylenebutylene-olefin crystal block copolymers, and acetalkoxyaluminum diarylates. One or more of these can be used.

[0076] Preferred commercially available calcium salts of phosphate esters that can be used include CrodaxDP-301LA (manufactured by Croda Japan Co., Ltd.). The fine silica particles that can be used include hydrophilic fine silica particles and hydrophobic fine silica particles. Preferred commercially available hydrophilic silica particles include AEROSIL-300 and AEROSIL-380 (manufactured by Nippon Aerosil Co., Ltd.), while preferred commercially available hydrophobic silica particles include AEROSIL-974D and AEROSIL-972 (manufactured by Nippon Aerosil Co., Ltd.).

[0077] Furthermore, preferred commercially available polystyrene-polyethylene / butylene rubber-polystyrene block copolymers include Kraton GFG-1901X, Kraton GG-1650 (both manufactured by Shell Japan), Septon 8007, and Septon 8004 (both manufactured by Kuraray). In addition, preferred commercially available polystyrene-polyethylene / propylene rubber-polystyrene block copolymers include Kraton GG-1730 (manufactured by Shell Japan), Septon 2006, and Septon 2063 (both manufactured by Kuraray).

[0078] Preferred commercially available hydrogenated styrene-butadiene rubbers include DYNARON1320P, DYNARON1321P (both manufactured by JSR Corporation), ToughTec Hl041, and ToughTec Hl141 (both manufactured by Asahi Kasei Corporation).

[0079] Preferred commercially available products of styrene-ethylenebutylene-olefin crystal block copolymer include DYNARON4600P (manufactured by JSR Corporation), and preferred commercially available products of olefin crystal-ethylenebutylene-olefin crystal block copolymer include DYNARON6200P and DYNARON6201B (manufactured by JSR Corporation).

[0080] A preferred commercially available acetalkoxyaluminum diarylate is PlenAct AL-M (manufactured by Ajinomoto Fine Techno Co., Ltd.).

[0081] Among these thickeners, the use of thermoplastic olefin elastomers such as styrene-ethylenebutylene-olefin crystalline block copolymers and olefin crystalline-ethylenebutylene-olefin crystalline block copolymers is preferred in order to further exhibit the effects of the present invention.

[0082] Furthermore, in order to obtain an ink-following body that prevents ink back, it is preferable that the average value of the tanδ measured for each frequency while exponentially increasing in the frequency range of 1 to 63 rad / s be 1.0 or higher, and more preferably 1.7 to 3.4.

[0083] Here, tanδ is a value that represents the loss modulus of elasticity / storage modulus of elasticity. Conventionally, it was known that it was preferable for the average value of the tanδ measured for each frequency while exponentially increasing in the frequency range "1 to 63 rad / s" to be 1.0 or less. In the present invention, by making the average value of the tanδ measured for each frequency in the above range of 1 to 63 rad / s 1.0 or more, it is possible to absorb vibrations and prevent inkback.

[0084] As the material for forming the friction body, rubber elastic materials such as thermosetting rubbers like silicone rubber, nitrile rubber, ethylene propylene rubber, and ethylene propylene diene rubber, and thermoplastic elastomers such as styrene elastomers, olefin elastomers, polyester elastomers, and urethane elastomers, as well as mixtures of two or more rubber elastic materials, and mixtures of rubber elastic materials and synthetic resins can be used. The friction body is formed by configuring these materials so that the amount of Taber wear on the CS-17 wear wheel of the Taber wear tester is less than 25 mg under a load of 9.8 N and a 1000 rpm environment in the abrasion test (ASTM D1044) specified in JIS K7204.

[0085] Furthermore, alkylsulfonate phenyl esters and cyclohexanedicarboxylic acid esters may be added to the friction material. The inclusion of alkylsulfonate phenyl esters and cyclohexanedicarboxylic acid esters in the friction material allows for the erasure of handwriting without damaging the paper surface or blurring printed characters. In addition, it is preferable that the friction material has a durometer D hardness of 30 or higher as specified in JIS K6203. This ensures the required hardness and enables more stable rubbing action. The friction material can also be used as a touch pen or stylus pen, and conductivity may be added.

[0086] Furthermore, it is preferable that the friction element be colored with a color whose lightness value is lower than that of the thermochromic ink contained in the refill. In other words, when the thermochromic ink of the multi-core writing instrument 1 is transferred to the surface of the friction element without discoloration during use, the transfer of the thermochromic ink can be made less noticeable. In particular, by making the color of the friction element black or having a lightness value of 2.5 or less, surface staining associated with the use of the friction element can also be made less noticeable.

[0087] Lightness values ​​are determined using the Munsell color system with measuring devices such as a general-purpose colorimeter (TC-8600A, manufactured by Tokyo Denshoku Co., Ltd.). The lightness value of the friction material is measured on the surface, and the lightness value of the thermochromic ink is determined by measuring the ink on a line written on paper (old JIS P3201; high-quality paper made from 100% chemical pulp, basis weight range 40-157 g / m2, whiteness 75.0% or higher) at a writing speed of 4.5 m / min and a pitch interval of 0.1 mm. [Explanation of symbols]

[0088] 1 Multi-core writing instrument 2 shaft cylinder 3 Front axle 4 Center axis 5 Refills 6 springs 10 rear axle 20 Operating members 21 Operation protrusion 23 Cam groove 30 Rotating Member 34 Cam protrusion 40 Slide Cam 50 Knock Member 60 rotors 70 sliding sprocket

Claims

1. It comprises a barrel, a first operating part provided to be movable in the front-rear direction relative to the barrel, a plurality of writing elements, and a rotating member provided to be rotatable around the central axis relative to the barrel while holding the plurality of writing elements. As the first operating part moves back and forth, the first operating part and the rotating member cooperate to rotate the rotating member, causing one of the plurality of writing characters to move forward according to the position of the first operating part in the front-rear direction. The first operating section is located in the front half of the shaft cylinder, A cam groove is formed on one of the first operating part and the rotating member, and a cam projection is formed on the other of the first operating part and the rotating member, and the cam groove and the cam projection cooperate to rotate the rotating member, and the cam groove is formed in a spiral shape around the central axis, A multi-core writing instrument characterized in that the cam groove is not formed around the entire circumference of the first operating part and the rotating member.

2. The device further comprises a second operating section, and by a knocking operation that presses the second operating section forward, the forward-moving writing element extends and retracts relative to the barrel. The multi-core writing instrument according to claim 1, characterized in that at least one of the plurality of writing elements contains heat-changeable ink, and all or part of the first operating section or the second operating section is an erasing section capable of erasing the writing of the writing element.

3. The eraser unit is characterized in that, in an abrasion test (ASTM D1044) specified in JIS K7204, under a load of 9.8 N and a 1000 rpm environment, the amount of Taber abrasion on the CS-17 abrasion wheel of the Taber abrasion tester is less than 25 mg and the durometer D hardness is 30 or higher, as described in claim 2.

4. The device further comprises a second operating section, and by a knocking operation that presses the second operating section forward, the forward-moving writing element extends and retracts relative to the barrel. The multi-core writing instrument according to claim 1, characterized in that the second operating section can be used as a touch pen or stylus pen.

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