JP6965011B2 - Multi-core writing tool - Google Patents

Description

The present invention relates to a multi-core writing instrument having a plurality of refills.

A multi-core writing tool having a plurality of refills and capable of selectively appearing a desired refill is known (Patent Document 1). The multi-core writing instrument described in Patent Document 1 is provided with a friction portion that discolors the handwriting at the rear end of the barrel, and a plurality of operating portions (sliding bodies) are arranged along the circumferential direction on the side surface of the barrel. There is. Each of the operating units is slidable in the axial direction. A plurality of refills are arranged in the barrel, and each of the refills is connected to a corresponding operation unit. By sliding the operation unit corresponding to the desired refill forward, the refill can be put into the writing state.

Japanese Unexamined Patent Publication No. 2013-49192

In the multi-core writing tool described in Patent Document 1, even when the same refill is continuously used, every time the refill appears and disappears, the operation unit corresponding to the desired refill is again selected from the plurality of operation units. You have to reselect. That is, for example, in a multi-core writing tool having three refills containing black, red, and blue inks, when writing in black, once writing in black, returning to the non-writing state, and then again. If you try to write in black, you have to reselect the operation unit corresponding to black from the three operation units, which is troublesome.

Further, in the multi-core writing instrument described in Patent Document 1, in order to change from the writing state to the non-writing state, the writing state is released by lightly sliding the operation unit corresponding to the refill that is not in the writing state forward. .. Therefore, when the multi-core writing tool is changed, another operation unit may be operated by mistake, and the writing state may be unintentionally released.

An object of the present invention is to provide a multi-core writing tool capable of easily repeating the appearance of the same refill.

According to one aspect of the present invention, the plurality of writing instruments, a knocking member, and a rotation selection member rotatably provided around the axis with respect to the barrel are provided. At least one of the cursives contains thermochromic ink, and one of the plurality of cursives is placed in an advanced position in response to the rotation of the rotation selection member, and is knocked to the advanced position. Provided is a multi-core writing instrument characterized in that the arranged cursive body protrudes from the barrel and is in a writing state. In the axial direction of the multi-core writing instrument, the writing part side is defined as the "front" side, and the side opposite to the writing part is defined as the "rear" side.

Further, according to another aspect, an erasing member for erasing the handwriting by the multi-core writing instrument is further provided.

Further, according to another aspect, the cover member is further provided, the erasing member is provided on the knock member, and the cover member is fitted to the erasing member.

Further, according to another aspect, the first locking portion is provided in the barrel, the second locking portion is provided in the knock member, and the first locking portion and the second locking portion are provided in the writing state. By locking the locking portion, the rotation of the rotation selection member is restricted.

Further, according to another aspect, the erasing member is a plastic eraser or an eraser, and at least one of the plurality of cursives can write an erasable handwriting using the plastic eraser or the eraser. Is. The term "erasable handwriting using a plastic eraser or eraser" means that the handwriting can be erased without soiling the paper surface around the handwriting by rubbing the handwriting with the plastic eraser or eraser. say.

According to the aspect of the present invention, it is possible to obtain a common effect of providing a multi-core type writing tool capable of easily repeating the appearance and appearance of the same refill.

It is a vertical sectional view of the multi-core writing instrument according to the embodiment of the present invention in a non-writing state. It is a vertical cross-sectional view of the writing state of a multi-core writing instrument. It is a partial cross-sectional view of a multi-core writing instrument in a non-writing state. It is a vertical sectional view of a rear axle. It is a vertical sectional view of the rotation selection member. It is a perspective view of the knock member. It is a perspective view of a rotary cam. It is a perspective view of a sliding top. It is a schematic diagram explaining the cooperative operation of the 2nd cam and the 2nd cam projection. It is a schematic diagram explaining the cooperative operation of the 1st cam and the 1st cam protrusion. It is sectional drawing in line AA of FIG. It is sectional drawing in line BB of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Corresponding components are designated by a common reference symbol throughout the drawing.

FIG. 1 is a vertical cross-sectional view of the multi-core writing instrument 1 in a non-writing state according to an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of the multi-core writing instrument 1 in a writing state, and FIG. It is a partial cross-sectional view of the core type writing instrument 1 in a non-writing state. In the present specification, in the axial direction of the multi-core writing instrument 1, the side of the writing unit 4 described later is defined as the "front" side, and the side opposite to the writing unit 4 is defined as the "rear" side. Further, the "axis" or "central axis" means the central axis of the multi-core writing tool 1 unless otherwise specified.

The multi-core writing tool 1 is attached to a shaft cylinder 3 having a front shaft 2 and a rear shaft 10 and formed in a cylindrical shape as a whole, and a rear end of the shaft cylinder 3, that is, a rear end of the rear shaft 10, and as a whole. It has a rotation selection member 20 formed in a cylindrical shape. The front shaft 2 and the rear shaft 10 are attached by screwing the rear end portions of the front shaft 2 into each other in the front end portion of the rear shaft 10. The barrel 3 contains three cursive bodies having a writing unit 4, that is, a refill 5. A hole for projecting the writing portion 4 of the refill 5 is formed at the front end of the front shaft 2.

A knock member 30 is arranged in the axle cylinder 3 behind the refill 5. The knock member 30 is urged rearward by a spring 6. An erasing member 7 is provided at the rear end of the knock member 30. The erasing member 7 is covered with a cover member 8 formed in a cylindrical shape. The cover member 8 is detachably attached to the rear end of the knock member 30. Three sliding pieces 50 are arranged between the outer peripheral surface of the knock member 30 and the inner peripheral surface of the barrel 3. The rear end portion of the refill 5 is connected to each of the sliding pieces 50. A rotary cam 40 is arranged near the rear end of the knock member 30.

FIG. 4 is a vertical cross-sectional view of the rear axle 10. A smaller diameter portion 11 is formed at the rear end portion of the rear shaft 10. The first engaging projection 12 is formed in an annular shape on the outer peripheral surface near the rear end portion of the small diameter portion 11. Inside the rear shaft 10, a partition wall 13 is formed that separates the inside of the rear shaft 10 from front to back. As shown in the cross-sectional view of FIG. 11 to be described later, a through hole 14 into which the knock member 30 is inserted is formed in the center of the partition wall 13, and each of the refills 5 is formed around the through hole 14. The three through holes 15 to be inserted are formed concentrically. Further, on the inner peripheral surface behind the partition wall 13, three guide walls 16 extending inward in the radial direction are formed up to the rear end portion of the rear shaft 10. A rib-shaped locking projection 17, which is a first locking portion, is formed on the top surface of the guide wall 16, that is, a flat surface facing the central axis. The guide wall 16 near the rear end portion of the rear shaft 10 has a thin wall thickness, whereby a step portion 18 is formed.

FIG. 5 is a vertical cross-sectional view of the rotation selection member 20. The rear end wall of the rotation selection member 20 is formed with a through hole 21 for projecting the rear end portion of the knock member 30 or the erasing member 7. Two second engaging protrusions 22 are formed at positions facing each other on the inner peripheral surface of the rotation selection member 20 near the front end opening. Each of the second engaging protrusions 22 is formed between two vertical holes 22a extending in the axial direction. Since the second engaging projection 22 is sandwiched by the vertical hole 22a, the portion of the rotation selection member 20 around the second engaging projection 22 is easily deformed, so that the second engaging projection 22 is radially located. It can move slightly inward or radially outward. On the inner peripheral surface behind the second engaging projection 22, four guide grooves 23 extending in the axial direction are formed at equal intervals along the circumferential direction. The guide groove 23 extends to the stop portion 23a, which is a step near the center of the rotation selection member 20 in the axial direction.

A groove having a complicated shape is formed on the inner peripheral surface behind the stop portion 23a, and the first cam 24 is formed by the wall surface defining the groove. That is, the first cam 24 is formed by the wall surfaces of the eight first protrusions 24a and the four second protrusions 24b defined by the grooves. The eight first protrusions 24a are formed at equal intervals along the circumferential direction. The four second protrusions 24b are formed at equal intervals along the circumferential direction immediately behind the first protrusion 24a. Each of the first protrusions 24a has a first slope 25. Each of the second protrusions 24b has two second slopes 26 that are parallel along the circumferential direction. A vertical groove 27 extending to the rear end wall of the rotation selection member 20 is formed between the second protrusions 24b. A stop groove 28 extending slightly rearward is formed between the two second slopes 26 of the second protrusion 24b.

The front end portion of the rotation selection member 20 is rotatably attached around the rear end portion of the barrel 3, that is, the rear end portion of the rear shaft 10. That is, in order to insert the front end opening of the rotation selection member 20 into the rear end portion of the rear shaft 10, the second engagement protrusion 22 of the rotation selection member 20 comes into contact with the first engagement protrusion 12 of the rear shaft 10. .. When the rotation selection member 20 is pushed against the rear shaft 10, the second engaging protrusion 22 moves outward in the radial direction, gets over the first engaging protrusion 12, and fits in a snap manner. As a result, the rotation selection member 20 can rotate around the axis without deviating from the rear shaft 10.

FIG. 6 is a perspective view of the knock member 30. The knock member 30 has a columnar main body member 31. A columnar annular portion 31a having a larger diameter is formed on the outer peripheral surface of the main body member 31. Four guide protrusions 32 are formed at equal intervals along the circumferential direction on the outer peripheral surface of the annular portion 31a. A groove is formed over the entire circumference on the outer peripheral surface of the main body member 31 in front of the annulus portion 31a, and the second cam 33 is formed by the wall surface defining the groove. A columnar shape having a smaller diameter is formed in front of the main body member 31 via a step portion 31b, and a plurality of locking grooves 34 extending in the axial direction, which are second engaging portions, are formed on the outer peripheral surface thereof. ing. A columnar guide rod 35 having a smaller diameter is formed in front of the locking groove 34 via a step portion 35a.

A columnar fitting portion 36 having a smaller diameter is formed behind the main body member 31. Two locking claws 37 are formed on the outer peripheral surface of the fitting portion 36 at positions symmetrical to the axis. Two fitting protrusions 38 are formed on the outer peripheral surface behind the locking claw 37 at positions symmetrical to the axis. A mushroom-shaped holding projection 39 extending rearward and having a bulging tip is formed on the rear end surface of the fitting portion 36. Although the erasing member 7 is fitted to the holding protrusion 39, the erasing member 7 may be formed by two-color molding. The fitting protrusion 38 fits into a recess or a through hole formed in the cover member 8, whereby the cover member 8 is detachably attached to the rear end portion of the knock member 30.

Instead of fitting the cover member 8 with the knock member 30, the cover member 8 may be fitted with the erasing member 7. That is, the erasing member 7 may be formed so as to have an outer diameter slightly larger than the inner diameter of the cover member 8, or may be formed so as to have a protrusion that abuts on the inner peripheral surface of the cover member 8. As a result, the cover member 8 is securely attached, and it is possible to prevent the cover member 8 from being unintentionally detached.

In the assembled state, the guide rod 35 of the knock member 30 is inserted into the spring 6 and inserted into the through hole 14 of the rear shaft 10. One end of the spring 6 is supported by the step portion 35a of the knock member 30, and the other end of the spring 6 is supported by the partition wall 13 of the rear shaft 10. As a result, the knock member 30 is urged rearward by the urging force of the spring 6. Each of the four guide protrusions 32 of the knock member 30 is arranged in the four guide grooves 23 of the rotation selection member 20. Therefore, the guide protrusion 32 of the knock member 30 slides in the guide groove 23 of the rotation selection member 20, so that the knock member 30 can be stably moved back and forth. The forward movement of the knock member 30 is regulated by the step portion 31b of the knock member 30 coming into contact with the step portion 18 of the rear shaft 10, and the backward movement of the knock member 30 is such that the guide protrusion 32 of the knock member 30 is a rotation selection member 20. It is regulated by abutting on the stop portion 23a.

FIG. 7 is a perspective view of the rotary cam 40. The rotary cam 40 is formed in a hollow columnar shape. Two columnar first cam protrusions 41 are formed on the outer peripheral surface of the rotary cam 40 at positions symmetrical to the axis. The rotary cam 40 is rotatably attached around the axis to the fitting portion 36 at the rear end of the knock member 30. That is, when the rotary cam 40 is inserted while being pushed into the fitting portion 36 of the knock member 30, the rotary cam 40 crosses the locking claw 37 and comes into contact with the rear end surface of the main body member 31 of the knock member 30 to be attached. Complete. The rotary cam 40 has an inner peripheral surface having an inner diameter slightly larger than the outer diameter of the fitting portion 36. Therefore, the rotary cam 40 can be easily rotated around the axis while being attached to the knock member 30. Further, the locking claw 37 is locked with the rotary cam 40 to prevent the rotary cam 40 from being disengaged rearward.

In the assembled state, the first cam protrusion 41 of the rotary cam 40 is arranged in the groove including the first cam 24 of the rotary selection member 20. Therefore, the first cam protrusion 41 of the rotary cam 40 cooperates with the first cam 24 of the rotation selection member 20 as described later with reference to FIG. 10, and the writing state and the non-writing state of the multi-core writing instrument 1 To be selectively maintained.

FIG. 8 is a perspective view of the sliding top 50. As shown in the cross-sectional view of FIG. 12, which will be described later, the sliding top 50 is a columnar member obtained by vertically dividing a hollow cylinder at a central angle of 120 degrees. The wall thickness of the first half body 51 is formed to be thicker than the wall thickness of the second half body 52. An insertion hole 53 into which the refill 5 is inserted is formed on the front end surface of the front half body 51 so as to extend in the axial direction. The insertion hole 53 opens in a rectangular shape toward the cylindrical inner surface of the front half body 51. A cylindrical second cam protrusion 54 is formed on the cylindrical inner surface of the latter half body 52.

In the assembled state, each of the three sliding pieces 50 is arranged between the guide walls 16 of the rear axle 10 as shown in FIG. Further, the second cam protrusion 54 of the sliding piece 50 is arranged in the groove including the second cam 33 of the knock member 30. Therefore, the second cam protrusion 54 of the sliding piece 50 cooperates with the second cam 33 of the knock member 30 to advance one predetermined sliding piece 50, as will be described next with reference to FIG. The remaining two sliding pieces 50 are retracted or stagnated.

FIG. 9 is a schematic view illustrating the cooperative operation of the second cam 33 and the second cam protrusion 54. FIG. 9 shows the positions of the three second cam protrusions 54, that is, the positions of the three sliding pieces 50 with respect to the second cam 33 deployed in the circumferential direction. In FIG. 9, the upper side is the rear end side of the multi-core writing tool 1, and the lower side is the front end side of the multi-core writing tool 1. Since the second cam 33 is formed by the wall surface of one groove as described above, the left and right sides of the second cam 33 in FIG. 9 are connected.

As will be described later with reference to FIG. 10, the multi-core writing instrument 1 is a knock-type writing instrument that can selectively switch between a writing state and a non-writing state by knocking the rear end portion of the multi-core writing instrument 1. Is. By the knock operation, the refill 5 which is relatively advanced among the three refills 5 protrudes from the hole at the front end of the front shaft 2, and the multi-core writing instrument 1 is in the writing state. That is, the knock member 30 on which the second cam 33 is formed by the knock operation, the sliding piece 50 having the second cam protrusion 54 that cooperates with the second cam 33, and the refill 5 connected to the sliding piece 50. However, only the refill 5 that moves forward as a unit and moves relatively forward can protrude from the hole at the front end of the front shaft 2. Therefore, when the knock operation is performed in the state of FIG. 9A, the refill 5 connected to the sliding piece 50 on the left side of the figure, which is relatively advanced, is in the writing state.

When it is desired to change the refill 5 to be written, the refill 5 is rotated about the axis with respect to the barrel 3 while grasping the rotation selection member 20. When the rotation selection member 20 is rotated, the guide protrusion 32 of the knock member 30 is arranged in the guide groove 23 of the rotation selection member 20, so that the rotation selection member 20 and the knock member 30 are integrated. Rotate. At this time, the rotation of the sliding top 50 is restricted by the guide wall 16 around the axis. Therefore, the second cam 33 of the knock member 30 moves relative to the second cam protrusion 54 of the sliding piece 50. As will be described later, the rotation selection member 20 can be rotated only when the multi-core writing instrument 1 is in the non-writing state, and cannot be rotated when the multi-core writing instrument 1 is in the writing state.

Specifically, when the rotation selection member 20 is rotated in the direction of the arrow in the drawing from the state of FIG. 9A, the second cam 33 and the second cam protrusion 54 are caused by the relative movement of the second cam 33. The sliding piece 50 on the left side of the figure moves backward and the sliding piece 50 in the center of the figure moves forward, resulting in the state shown in FIG. 9B. The sliding piece 50 on the right side of the figure remains retracted. When the knock operation is performed in this state, the refill 5 connected to the sliding piece 50 in the center of the drawing is in the writing state.

When the rotation selection member 20 is further rotated in the direction of the arrow in the drawing from the state of FIG. 9B, the second cam 33 and the second cam protrusion 54 cooperate with each other due to the relative movement of the second cam 33. Then, the sliding piece 50 in the center of the figure retracts and the sliding piece 50 on the right side of the figure moves forward, resulting in the state shown in FIG. 9 (C). The sliding piece 50 on the left side of the figure remains retracted. When the knock operation is performed in this state, the refill 5 connected to the sliding piece 50 on the right side of the drawing is in the writing state. When the rotation selection member 20 is further rotated in the direction of the arrow in the figure from the state of FIG. 9 (C), the state of FIG. 9 (A) is returned again, and this is repeated. As a matter of course, it may be rotated in the direction opposite to the arrow in the figure.

The side surface of the barrel 3 may be opened or transparent or translucent so that it can be determined which refill 5 is in the writing state by the knock operation, that is, which sliding piece 50 and the refill 5 are in the advanced position. .. Specifically, when an opening is provided on the side surface of the shaft cylinder 3, the side surface of the corresponding shaft cylinder 3 of each sliding piece 50 is visible from the opening only when the sliding piece 50 is in the advanced position. An opening may be formed in. The sliding piece 50 may be colored with the same color as the writing color of the refill 5 to be inserted.

FIG. 10 is a schematic view illustrating a cooperative operation of the first cam 24 and the first cam protrusion 41, that is, a knock operation. FIG. 10 shows the position of one of the first cam protrusions 41 with respect to a part of the first cam 24 developed in the circumferential direction. In FIG. 10, the upper side is the rear end side of the multi-core writing tool 1, and the lower side is the front end side of the multi-core writing tool 1. The circles numbered in the figure indicate the positions of the first cam protrusions 41 that change with time in the order of the numbers. Therefore, in the following description, the positions of the first cam protrusions 41 are referred to as position 1, position 2, ..., Position 7.

When the first cam protrusion 41 is in the position 1, that is, in the vertical groove 27 of the rotation selection member 20, this indicates the case where the multi-core writing instrument 1 is in the non-writing state. From this state, when the rear end portion of the multi-core writing tool 1 is knocked, that is, when the operating portion, that is, the cover member 8, the erasing member 7, and the knock member 30 are pressed forward against the urging force of the spring 6, the operating portion, that is, the cover member 8, the erasing member 7, and the knock member 30 are pressed forward. The rotary cam 40 advances together with the knock member 30. As a result, the first cam protrusion 41 of the rotary cam 40 moves forward in the vertical groove 27 and comes into contact with the first slope 25 of the rotary selection member 20. When the first cam protrusion 41 comes into contact with the first slope 25, the first cam protrusion 41 receives a component force in the circumferential direction while sliding the first slope 25 as shown at position 2, and the rotary cam 40 receives a component force in the circumferential direction. Rotate around the axis.

When the advancement of the knock member 30 is stopped by the contact between the step portion 31b of the knock member 30 and the step portion 18 of the rear shaft 10, the first cam protrusion 41 is at the position 3. Next, when the pressing of the operating portion is released, the knock member 30 and the rotary cam 40 are retracted by the urging force of the spring 6. As a result, the first cam protrusion 41 comes into contact with the second slope 26 of the rotation selection member 20 behind the position 3. When the first cam protrusion 41 comes into contact with the second slope 26, the first cam protrusion 41 receives a component force in the circumferential direction while sliding on the second slope 26 as shown at position 4, and the rotary cam 40 receives a component force in the circumferential direction. Rotate around the axis. The slide of the first cam protrusion 41, that is, the retracting of the knock member 30, is stopped when the first cam protrusion 41 moves to the position 5 and fits into the stop groove 28. At this time, as described with reference to FIG. 9, the refill 5 connected to the sliding top 50 at the advanced position is in the writing state.

In order to shift the multi-core writing instrument 1 from the writing state to the non-writing state, the knock operation is performed again. That is, when the knock operation is performed from the state where the first cam protrusion 41 is in the position 5, the first cam protrusion 41 comes into contact with the first slope 25 and slides. Next, the first cam protrusion 41 abuts on the second slope 26 and slides through the position 6, enters the vertical groove 27 next to the vertical groove 27 at the position 1, and moves backward. As described above, the backward movement of the first cam protrusion 41 in the vertical groove 27 is stopped when the guide protrusion 32 of the knock member 30 comes into contact with the stop portion 23a of the rotation selection member 20, and the first cam protrusion 41 is located at position 7. As a result, the multi-core writing instrument 1 is in a non-writing state.

FIG. 11 is a cross-sectional view taken along the line AA of FIG. As described above, FIG. 1 shows the non-writing state of the multi-core writing instrument 1, and the line AA is a portion including the vicinity of the rear end portion of the locking projection 17 of the rear shaft 10 in the axial direction. It is a line. As shown in FIG. 11, in the non-writing state, the rear shaft 10 and the knock member 30 are not locked with respect to the rotation around the axis.

FIG. 12 is a cross-sectional view taken along the line BB of FIG. As described above, FIG. 2 shows the writing state of the multi-core writing instrument 1, and the line BB of FIG. 2 is a line at the same position with respect to the line AA of FIG. 1 and the rear shaft 10. be. As shown in FIG. 12, in the writing state, the rear shaft 10 and the knock member 30 are locked with respect to the rotation around the axis. That is, since the knock member 30 is in a relatively advanced position in the writing state, a corresponding part of the locking projection 17 of the rear shaft 10 is arranged in the locking groove 34 of the knock member 30.

Therefore, in the non-writing state of the multi-core writing instrument 1, the rotation selection member 20 and the knock member 30 can be integrally rotated around the axis. On the other hand, in the writing state of the multi-core writing instrument 1, the rotation selection member 20 and the knock member 30 are integrally formed with the rotation selection member 20 by locking the locking projection 17 of the rear shaft 10 and the locking groove 34 of the knock member 30. Cannot rotate. Therefore, it is possible to prevent a malfunction in which the rotation selection member 20 is unintentionally rotated during writing and the refill 5 is changed.

Further, even if the writing state is changed to the non-writing state by the knock operation, the same sliding top 50 is in the advanced position as long as the rotation selection member 20 is not rotated as described with reference to FIG. Therefore, for example, when writing in black and then knocking to put it in a non-writing state and then trying to write in black again, a single operation unit is knocked without selecting an operation unit. Just by doing this, you can put the black refill in the writing state again. That is, by knocking a single operation unit without searching for a predetermined operation unit in order to project a desired refill from a plurality of operation units each time, the same refill 5 appears and disappears repeatedly. It's easy to do. On the other hand, switching the refill 5 that is in the writing state by the knock operation can be easily performed by rotating the rotation selection member 20 around the axis as described above.

Further, since each of the sliding pieces 50 moves back and forth by rotating the rotation selection member 20 around the axis, a plurality of springs that individually urge each of the refills 5 connected to the sliding pieces 50. There is no need to place. As a result, the multi-core writing tool 1 can have a simple mechanism because the ratio of the haunting mechanism and the refill selection mechanism to the total length in the axial direction can be reduced. Further, the outer surface of the multi-core writing tool 1 has few irregularities, and it is easy to print a pattern or decorate it.

In the above-described embodiment, the multi-core writing tool 1 has three refills 5, but may be two or four or more, and one of them is sharpened instead of the ballpoint pen refill. It may be a pencil or other type of refill. Further, the multi-core writing instrument 1 is provided with an erasing member 7 at the rear end thereof for erasing the handwriting by the multi-core writing instrument 1, but in addition to or instead of this, the multi-core writing instrument 1 is different. An erasing member may be provided at a location. For example, it may be provided on a part of the front shaft 2, for example, the front end portion, or a clip having a function of an erasing member may be provided on the side surface of the multi-core writing tool.

In the writing state of the multi-core writing instrument 1, the rotation of the rotation selection member 20 around the axis was restricted by locking the locking projection 17 of the rear shaft 10 and the locking groove 34 of the knock member 30, but the rear shaft A groove or a recess may be provided on the side, and a protrusion may be provided on the knock member side. Further, any shape may be adopted as long as the rotation of the rotation selection member is restricted. For example, protrusions may be provided on both the rear shaft side and the knock member side, and the protrusions and the protrusions may be locked.

The refill 5 in the above-described embodiment may contain a heat-changing ink containing a heat-coloring material. In this case, the multi-core writing instrument 1 is a heat-discoloring writing instrument, and the handwriting of the multi-core writing instrument 1 can be thermally discolored by the frictional heat generated when the writing instrument 1 is rubbed by a friction body as an erasing member.

Here, the thermochromic ink maintains a predetermined color (first color) at room temperature (for example, 25 ° C.), and changes to another color (second color) when the temperature is raised to a predetermined temperature (for example, 60 ° C.). This refers to an ink having the property of returning to the original color (first color) when cooled to a predetermined temperature (for example, −5 ° C.). In the multi-core writing instrument 1 using thermochromic ink, making the second color colorless and raising the temperature of the drawn line written with the first color (for example, red) to make it colorless is called "erasing" here. I will do it. Therefore, the drawn lines are rubbed against the written surface or the like on which the drawn lines are written by a friction body to generate frictional heat, whereby the drawn lines are changed to colorless, that is, erased. As a matter of course, the second color may be a color other than colorless.

The thermochromic microcapsule pigment used as a thermochromic coloring material is a pigment that changes color due to heat such as frictional heat, for example, if it has a function of changing from colored to colorless, colored to colored, colorless to colored, and the like. The present invention is not particularly limited, and various substances can be used, and examples thereof include microencapsulated thermal discoloring compositions containing at least a leuco dye, a color developer, and a discoloration temperature adjusting agent.

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, conventionally known inks such as triphenylmethane, spiropirane, fluorane, diphenylmethane, rhodamine lactam, indrillphthalide, and leucooramine are available from the viewpoint of obtaining ink having excellent color development characteristics. It can be used alone (1 type) or in combination of 2 or more types (hereinafter, simply referred to as "at least 1 type").

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- (N-p-tolyl-N-ethylamino) fluorane, 2- (N-phenyl-N-methylamino) -6- (N-p-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-dodecoxystylinoquinolin, and the like.

These leuco dyes have a lactone skeleton, a pyridine skeleton, a quinazoline skeleton, a bisquinazoline skeleton, and the like, and develop color when these skeletons (rings) are opened.

The color developer that can be used is a component having the ability to develop the color of the leuco dye, and is, for example, a phenol resin compound, a salicylic acid metal chloride, a salicylic acid resin metal salt compound, a solid acid compound, or the like. Can be mentioned.

Specifically, o-cresol, tertiary butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, hexafluorobisphenol, p. -Hydroxybenzoate n-butyl, p-hydroxybenzoate n-octyl, resorcin, 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 -Nonan, 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, but is usually 0.1 to 1 parts by mass with respect to 1 part by mass of the leuco dye described above. It is preferable to select within the range of about 100 parts by mass.

The discoloration temperature adjusting agent that can be used is a substance that controls the discoloration temperature in the coloration of the leuco dye and the color developer. As the discoloration temperature adjusting agent that can be used, conventionally known ones can be used. Specific examples thereof include alcohols, esters, ketones, ethers, acid amides, azomethines, fatty acids, hydrocarbons and the like.

More specifically, bis (4-hydroxyphenyl) phenylmethane dicaprelate (C ₇ H ₁₅ ), bis (4-hydroxyphenyl) phenylmethane dilaurate (C ₁₁ H ₂₃ ), bis (4-hydroxyphenyl) phenyl. Methanedimilistate (C ₁₃ H ₂₇ ), bis (4-hydroxyphenyl) phenyl ethane dimilistate (C ₁₃ H ₂₇ ), bis (4-hydroxyphenyl) phenylmethane dipalmitate (C ₁₅ H ₃₀ ), bis At least one such as (4-hydroxyphenyl) phenylmethanedibehenate (C ₂₁ H ₄₃ ), bis (4-hydroxyphenyl) phenylethylhexylidene dimystate (C ₁₃ H ₂₇ ) and the like can be mentioned.

The amount of the discoloration temperature adjusting agent used may be appropriately selected according to the desired hysteresis width, the color density at the time of color development, and the like, and is not particularly limited, but is usually, with respect to 1 part by mass of the leuco dye. , It is preferable to use within the range of 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 color developer, and a color change temperature adjusting agent so that the average particle size is 0.2 to 5 μm. Can be manufactured. Examples of the microencapsulation method include interfacial polymerization method, interfacial polycondensation method, insitu polymerization method, in-liquid curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melting dispersion cooling method, and air. Examples thereof include a suspension coating method and a spray drying method, which can be appropriately selected depending on the intended use.

For example, in the phase separation method from an aqueous solution, a leuco dye, a color developer, and a discoloration temperature adjuster are heated and melted, then put into 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-based resin solution, etc. are gradually added, and the reaction is continued to prepare the mixture, and then the dispersion is filtered to produce the desired thermochromic microcapsule pigment. be able to.

The contents of these leuco dyes, color developing agents, and discoloration temperature adjusting agents vary depending on the leuco dye, coloring agent, type of discoloring temperature adjusting agent, microencapsulation method, etc. used. The color developer 0.1 to 100 and the discoloration temperature adjusting agent 1 to 100 by mass ratio. Further, the capsule membrane agent has a mass ratio of 0.1 to 1 with respect to the capsule contents.

The thermochromic microcapsule pigment has a color development temperature (for example, color development at 0 ° C. or higher) and a decolorization temperature (for example, color development at 0 ° C. or higher) and a decolorization temperature (for example, color development at 0 ° C. or higher) by appropriately combining the types and amounts of the leuco pigment, the color developer and the color change temperature adjusting agent. For example, (decoloring at 50 ° C. or higher) can be set to a suitable temperature, and it is preferable that the color changes from colored to colorless due to heat such as frictional heat.

In the thermochromic microcapsule pigment, the wall film is preferably formed of a urethane resin, a urea / urethane resin, an epoxy resin, or an amino resin from the viewpoint of further improving the drawing density, storage stability, and writability. Examples of the urethane resin include compounds of isocyanate and polyol. Examples of the epoxy resin include a compound of an epoxy resin and an amine. Examples of the amino resin include melamine resin, urea resin, and benzoguanamine resin. The thickness of the wall film of the microcapsule coloring material is appropriately determined according to the required strength of the wall film and the drawing density.

The average particle size of the heat-discoloring microcapsule pigment suppresses adverse effects on colorability, color development, easy decolorization, stability, fluidity in ink, and writeability, and photocolor change described later. From the viewpoint of compatibility with the microcapsule pigment, the thickness is preferably 0.2 to 5 μm, more preferably 0.3 to 3 μm. The "average particle size" specified here is a value obtained by measuring the average particle size (50% diameter) (refractive index 1.8) with a particle size analyzer [Microtrack HRA9320-X100 (manufactured by Nikki Sosha Co., Ltd.)]. Is.

If the average particle size is less than 0.2 μm, a sufficient drawing density cannot be obtained, while if it exceeds 5 μm, the writing property is deteriorated, the dispersion stability of the heat-discoloring microcapsule pigment is lowered, and the ink due to vibration is generated. It is not preferable because backing is likely to occur. Further, 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 remarkable. The microcapsule pigment in the above-mentioned average particle size range (0.2 to 5 μm) varies depending on the microencapsulation method, but in the phase separation method from an aqueous solution or the like, stirring is performed when producing the microcapsule pigment. It can be prepared by a suitable combination of conditions.

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 out of this range, the dispersion stability of the microcapsule pigment tends to decrease. Further, the microcapsule pigment having a specific gravity of more than 1.3 is liable to cause ink back due to vibration.

In the water-based ink composition for writing tools, in addition to the above-mentioned heat-discoloring microcapsule pigment, water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.) as a solvent as a balance, and for each writing tool (ballpoint pen). Depending on the application (for marking pens, etc.), a water-soluble organic solvent, thickener, lubricant, rust preventive, preservative or antibacterial agent, etc. may be appropriately contained as long as the effect is not impaired. can.

Examples of the water-soluble organic solvent 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. Ether can be used alone or in combination.

Of these, glycerin is preferably used for the purpose of suppressing ink solidification in the writing portion due to ink back, and the amount of glycerin added is preferably 1 to 10% by mass with respect to the total amount of ink. The mechanism of action by glycerin is unknown, but it is presumed that it has the effect of reducing the cohesive force of pigments and ink components in a dry state.

As the thickener that can be used, for example, at least one selected from the group consisting of synthetic polymers, cellulose and polysaccharides is preferable. Specifically, Arabic gum, tragacant gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, welan gum, succinoglycan, dieutan gum, dextran, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, starch glycolic acid and The salt, propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinylmethyl ether, polyacrylic acid and its salt, carboxyvinyl polymer, polyethyresioxide, copolymer of vinyl acetate and polyvinylpyrrolidone, crosslinked acrylic acid polymer and Examples thereof include a non-crosslinked acrylic acid polymer and a salt thereof, a styrene acrylic acid copolymer and a salt thereof, and the like.

Of these, it is preferable to use polysaccharides. Due to its rheological properties, polysaccharides tend to be less susceptible to fluidity due to vibration, and are less likely to cause problems such as writing defects due to ink back. In particular, xanthan gum is preferable because it has an excellent balance with other characteristics required for writing instrument ink.

As the lubricant, fatty acid ester of polyhydric alcohol, which is also used as a surface treatment agent for pigments, higher fatty acid ester of sugar, polyoxyalkylene higher fatty acid ester, alkyl phosphate ester, alkyl sulfonate of higher fatty acid amide, alkyl allyl sulfone. Examples thereof include esters, derivatives of polyalkylene glycols, fluorine-based surfactants, and polyether-modified silicones. Examples of the rust preventive include benzotriazole, tolyltriazole, dicyclohexylammonium nitrate, saponins and the like. Examples of the preservative or antibacterial agent include phenol, sodium omadin, sodium benzoate, and benzimidazole compounds.

In order to produce this water-based ink composition for writing utensils, a conventionally known method can be adopted. 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 value of the water-based ink composition for writing tools 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 in the above range, it is possible to obtain an ink having excellent writability 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 required non-Newtonian viscosity index n is preferably 0.2 to 0.6. By setting the non-Newtonian viscosity index n in the above range in addition to the above viscosity range, it is possible to appropriately set the fluidity of the ink with respect to vibration, and it is possible to prevent the occurrence of ink back.

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

In the refill, the ink follower may be arranged immediately behind the ink. The material constituting the follower can be composed of at least a non-volatile or refractory organic solvent and a thickener. The non-volatile or refractory organic solvent used for the ink follower is used as the base oil of the ink follower, and for example, liquid paraffin is used. Mineral oils and chemically synthesized oils are used as the liquid paraffin, and polybutene, polyα-olefins, ethylene α-olefin oligomers and the like can be used as the chemically synthesized oils.

Specific examples of the mineral oil that can be used include 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 (all manufactured by Nippon Oil & Fats Co., Ltd.), and polybutene. Examples include HV-15 (manufactured by Nippon Petrochemical Co., Ltd.) and 35R (manufactured by Idemitsu Kosan Co., Ltd.).

Specific 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, and the like. (P-10000, P-37500) (manufactured by Matsumura Petroleum 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) (above, Mitsui). (Made by Chemicals), etc.

These non-volatile or non-volatile organic solvents can be used alone or in combination of two or more.

Examples of the thickener used for the ink follower include calcium salt of phosphate ester, fine particle silica, polystyrene-polyethylene / butylene rubber-polystyrene block copolymer, polystyrene-polyethylene / propylene rubber-polystyrene block copolymer, and hydrogenated styrene. Examples thereof include-butadiene rubber, block copolymers of styrene-ethylenebutylene-olefin crystals, block copolymers of olefin crystals-ethylenebutylene-olefin crystals, and acetoalkoxyaluminum dialchelates, and these can be used alone or in combination of two or more.

Preferred commercially available products of the calcium salt of the phosphoric acid ester that can be used include Crodax DP-301LA (manufactured by Croda Japan Co., Ltd.) and the like. The fine particle silica that can be used includes hydrophilic fine particle silica and hydrophobic fine particle silica, and preferable commercially available products of hydrophilic silica include AEROSIL-300 and AEROSIL-380 (manufactured by Nippon Aerosil Co., Ltd.). Preferred commercially available products of hydrophobic silica include AEROSIL-974D, AEROSIL-972 (manufactured by Nippon Aerosil Co., Ltd.) and the like.

Preferred commercially available polystyrene-polyethylene / butylene rubber-polystyrene block copolymers include Clayton GFG-1901X, Clayton GG-1650 (above, Shell Japan), Septon 8007, Septon 8004 (above, Kuraray) and the like. Can be mentioned. Further, preferable commercially available products of polystyrene-polyethylene / propylene rubber-polystyrene block copolymers include Clayton GG-1730 (manufactured by Shell Japan Co., Ltd.), Septon 2006, Septon 2063 (manufactured by Kuraray Co., Ltd.) and the like.

Preferred commercially available products of hydrogenated styrene-butadiene rubber include DYNARON1320P, DYNARON1321P (above, manufactured by JSR Corporation), Toughtech Hl041, Toughtech Hl141 (above, manufactured by Asahi Kasei Kogyo Co., Ltd.) and the like.

Preferred commercial products of the block copolymer of styrene-ethylenebutylene-olefin crystal include DYNARON4600P (manufactured by JSR Corporation), and preferred commercial products of the block copolymer of olefin crystal-ethylenebutylene-olefin crystal include DYNARON6200P and DYNARON6201B (manufactured by JSR Corporation). (Made by JSR) and the like.

Preferable commercially available products of acetoalkoxyaluminum dialchelates include Plenact AL-M (manufactured by Ajinomoto Fine-Techno Co., Ltd.) and the like.

Among these thickeners, from the viewpoint of further exerting the effects of the present invention, thermoplastic olefin-based elastomers such as styrene-ethylenebutylene-olefin crystal block copolymers and olefin crystals-ethylenebutylene-olefin crystal block copolymers. Preferable to use.

Further, from the viewpoint of obtaining an ink follower that prevents the occurrence of ink back, the average value of the tan δ values measured for each frequency while increasing exponentially in the frequency domain 1 to 63 rad / s should be 1.0 or more. Is preferable, and 1.7 to 3.4 is more preferable.

Here, tan δ is a value meaning the loss elastic modulus / storage elastic modulus, and conventionally, the average value of the tan δ values measured for each frequency while increasing exponentially in the frequency domain “1-63 rad / s”. It has been known that a value of 1.0 or less is preferable. In the present invention, 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 vibration and prevent the occurrence of ink back.

Materials for forming the friction body include thermocurable rubbers such as 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. A rubber elastic material, a mixture of two or more kinds of rubber elastic materials, and a mixture of the rubber elastic material and a synthetic resin can be used, and this is subjected to a load test (ASTM D1044) specified in JIS K7204. In an environment of 8N and 1000 rpm, the amount of taber wear on the wear wheel CS-17 of the taber wear tester is configured to be less than 25 mg, and a friction body is formed.

Further, an alkyl sulphonic acid phenyl ester or a cyclohexanedicarboxylic acid ester may be added to the material of the friction body. By containing the alkyl sulphonic acid phenyl ester and the cyclohexanedicarboxylic acid ester in the friction body, it is possible to erase the handwriting without damaging the paper surface and blurring the printed characters and the like. Further, the friction body preferably has a durometer A hardness of 60 or more specified in JIS K6203. As a result, a predetermined hardness can be secured, and a more stable scraping operation becomes possible. The friction body can also be applied as a touch pen or a stylus pen, and may be provided with conductivity.

Further, the friction body is preferably colored with a color having a brightness value lower than that of the heat-discoloring ink contained in the multi-core writing tool 1. That is, when the heat-discoloring ink of the multi-core writing instrument 1 is transferred to the surface of the friction body without discoloration when the friction body is used, the transfer of the heat-discoloring ink can be made inconspicuous. In particular, by setting the color of the friction body to black or a lightness value of 2.5 or less, it is possible to make the surface stains due to the use of the friction body inconspicuous.

The lightness value uses the Munsell color system using a measuring device such as a general-purpose color difference meter (TC-8600A, manufactured by Tokyo Denshoku Co., Ltd.), and the lightness value of the friction body measures the surface of the thermochromic ink. The lightness value is a writing speed of 4.5 m / min on a paper surface (former JIS P3201; high-quality paper made from 100% chemical pulp, basis weight range 40 to 157 g / m2, whiteness 75.0% or more). It is obtained by measuring the ink on the drawn line written with a pitch interval of 0.1 mm.

Further, at least one of the plurality of refills 5 in the above-described embodiment is a refill that contains a mechanical pencil lead, a pencil lead, or an eraser erasable ink, and at least one of the remaining refills 5 contains a thermochromic ink. It may be a refill. In this case, by using a plastic eraser or an eraser as the erasing member 7, the handwriting by the mechanical pencil lead, the pencil lead or the eraser erasable ink can be erased. Further, the handwriting can be thermally discolored by scraping the handwriting with the heat-discoloring ink using a plastic eraser or an eraser to generate frictional heat.

Therefore, a plastic eraser or eraser can be used as an erasing member for different types of handwriting, i.e. a mechanical pencil lead, a pencil lead or an erasing member that erases handwriting with an eraser erasable ink, and a heat-discoloring ink. It can be used as a friction body that thermally discolors (erases) the handwriting. The term "erasable handwriting using a plastic eraser or eraser" as used herein means that the handwriting can be erased without soiling the paper surface around the handwriting by rubbing the handwriting with the plastic eraser or eraser. Say that.

The sharp core or pencil core has an average thickness of 0, for example, in which at least one fine particle (excluding glass powder) selected from an inorganic pigment, an organic pigment, and a dye is dispersed or included as a compounding composition before firing. .1 to 2 μm, flakes with an aspect ratio of 5 to 150 and a flatness of 200 nm or less, or granules with an average particle size of 0.1 to 50 μm and a sphericity of 0.1 to 50 μm. It is preferable that the glass powder is contained in an amount of 3 to 80% by weight based on the total amount of the pencil lead.

The eraser erasable ink has an average particle size of 2 to 20 μm, contains 5 to 30% by weight of non-thermoplastic colored resin particles with respect to the total amount of the ink composition, and has a glass transition point of less than 0 ° C. It is preferable to contain at least non-colored particles. As for the "average particle size" defined here, as described above, the average particle size (50% diameter) is measured with a particle size analyzer [Microtrack HRA9320-X100 (manufactured by Nikkiso Co., Ltd.)] (refractive index 1). It is the value obtained in 0.8).

In this case, the friction body has a primary particle size composed of a shell having a relatively high glass transition temperature (Tg) and a core having a relatively lower glass transition temperature (Tg) than the shell, in addition to the above-mentioned friction body. It contains an acrylic thermoplastic resin powder, a plasticizer, an inorganic powder and a thermoplastic resin having a size of 20 to 80 μm, the thermoplastic resin being a polyvinyl chloride resin or a copolymer thereof, and the inorganic powder being calcium carbonate and / Or magnesium carbonate is preferable because both the strokes of the thermoplastic ink and the strokes of the erasable ink can act by rubbing. The "glass transition temperature (Tg)" refers to the temperature at the boundary where the amorphous portion of the acrylic resin powder becomes more motility and becomes in a rubber state.

1 Multi-core writing tool 2 Front shaft 3 Axle cylinder 4 Writing part 5 Refill 6 Spring 7 Erasing member 8 Cover member 10 Rear shaft 20 Rotation selection member 30 Knock member 50 Sliding frame 40 Rotating cam

Claims (3)

It is provided with a shaft cylinder, a plurality of cursive bodies, a knock member, and a rotation selection member rotatably provided around the shaft line with respect to the shaft cylinder.
At least one of the plurality of cursives contains a thermochromic ink and
One of the plurality of cursives is arranged at an advanced position according to the rotation of the rotation selection member.
The knocking operation, the disposed advanced position the said writing body, Ri Do the written state protrude from the barrel,
A first locking portion is provided in the barrel, a second locking portion is provided in the knock member, and the first locking portion and the second locking portion are locked in the writing state. , multi-core type writing tool rotation of the rotary selection member is characterized Rukoto is restricted. The first locking portion is a rib-shaped locking projection provided on the inner peripheral surface of the barrel and extending inward in the radial direction, and the second locking portion is the outer periphery of the knock member. The multi-core writing tool according to claim 1 , wherein a plurality of locking grooves extending in the axial direction are provided on the surface. A sliding top on which a cam protrusion is formed is connected to each of the plurality of cursive writing bodies, a cam is formed on the knock member, and the cam protrusion and the cam cooperate with each other by rotation of the rotation selection member. The multi-core writing instrument according to claim 1 or 2, wherein one of the plurality of cursive writing instruments is arranged at an advanced position.

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