JP2018202859A - Writing instrument - Google Patents

Abstract

To provide a writing instrument which includes a coil spring for biasing a clip and inhibits removal of the coil spring from the writing instrument while securing easiness of attachment of the coil spring to the writing instrument.SOLUTION: A writing instrument 1 includes: a barrel 4; a clip 5 swingably connected with the barrel; and a coil spring 6 which is disposed between the barrel and the clip and biases the clip. A spring holding part 45 which is inserted into the coil spring is provided in at least one of the barrel and the clip. The invention provides the writing instrument 1 which is characterized in that projections 45c, 45d are provided on a side surface of the spring holding part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a writing instrument.

  Writing instruments such as ballpoint pens are often provided with clips. The clip has a role of preventing the writing instrument from rolling and a role of holding an article (paper, clothes, etc.) between the shaft tube and the clip.

  2. Description of the Related Art Conventionally, writing instruments that can change the distance between a clip and a shaft tube by swinging the clip with respect to the shaft tube are known (Patent Documents 1 and 2). In such a writing instrument, the clip is urged by a coil spring, and when the clip is separated from the shaft tube, the coil spring is compressed by a human finger.

  However, if the coil spring is not firmly held, the coil spring may come off the writing instrument when the coil spring is repeatedly expanded and contracted. On the other hand, in the writing instruments described in Patent Documents 1 and 2, a spring holding portion into which the coil spring is extrapolated is provided, and most of the coil spring is covered with a clip. This restricts the movement of the coil spring other than expansion and contraction, and prevents the coil spring from coming off the writing instrument.

JP 2006-130800 A JP 2014-58120 A

  However, in such a writing instrument, since the opening part of the space where a coil spring is arrange | positioned is very narrow, in order to attach a coil spring to a writing instrument, it is necessary to compress a coil spring largely. For this reason, the mounting property of the coil spring to the writing instrument deteriorates, and the productivity of the writing instrument decreases.

  Accordingly, in view of the above problems, an object of the present invention is to suppress the coil spring from coming off from the writing instrument while securing the mounting ability of the coil spring to the writing instrument in the writing instrument having the coil spring for biasing the clip. There is.

  In order to solve the above-described problem, in the first aspect, a shaft cylinder, a clip that is swingably connected to the shaft cylinder, and a coil spring that is disposed between the shaft cylinder and the clip and that biases the clip. A writing instrument is provided, wherein a spring holding part on which a coil spring is inserted is provided on at least one of the shaft cylinder and the clip, and a projection is provided on a side surface of the spring holding part. .

  Moreover, it is preferable that the protrusion is provided at a position separated from the base end of the spring holding portion.

  Moreover, it is preferable that a protrusion is provided in the front part of a spring holding part.

  According to a second aspect, in the first aspect, the protrusion includes a first protrusion provided at the base end of the spring holding portion and a second protrusion provided at a position spaced from the base end of the spring holding portion. The first protrusion and the second protrusion are separated from each other in the circumferential direction of the spring holding portion.

  In the third aspect, in the first aspect or the second aspect, the shaft cylinder or the clip is provided with a spring support portion that is disposed on the front side of the coil spring and supports the front end portion of the coil spring.

  In a 4th aspect, the clip holding part which hold | maintains a clip is further provided, and the width | variety of the inner surface of the said clip is shorter than the width | variety of the side surface of the said clip holding part.

  ADVANTAGE OF THE INVENTION According to this invention, in the writing instrument provided with the coil spring which urges | biases a clip, it can suppress that a coil spring remove | deviates from a writing instrument, ensuring the mounting property to a writing instrument of a coil spring.

FIG. 1 is a front view of a writing instrument according to an embodiment of the present invention. FIG. 2 is a front sectional view of the writing instrument of FIG. FIG. 3 is a front view of the inner cylinder, the clip, and the first coil spring when the clip is not operated. FIG. 4 is a front view of the inner cylinder, the clip, and the first coil spring when the clip is operated. FIG. 5 is a perspective view of the inner cylinder. FIG. 6 is a front view of the inner cylinder. FIG. 7 is a plan view of the inner cylinder. FIG. 8 is an enlarged front view of the spring holding portion. FIG. 9 is a perspective view of the clip. FIG. 10 is a front view of the clip. FIG. 11 is a bottom view of the clip. FIG. 12 is a front sectional view of the inner cylinder, the clip, and the first coil spring when the clip is operated. FIG. 13 is a left side view of the clip. FIG. 14 is an enlarged view of a portion A in FIG. 13 when the protruding portion is in contact with the rear shaft cylinder. FIG. 15 is an embodiment different from FIG. 1 and is a front view showing a state in which a clip is connected to the inner cylinder. FIG. 16 is a perspective view of the inner cylinder. FIG. 17 is a perspective view of the clip. FIG. 18 is a front view of a state where the clip is temporarily fastened before the clip is connected to the inner cylinder. FIG. 19 is a cross-sectional view of a state before a clip is temporarily fastened to the inner cylinder. 20 is a cross-sectional view taken along line LL in FIG.

  Hereinafter, the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals are assigned to the same or similar components.

  Hereinafter, with reference to FIG.1 and FIG.2, the structure of the writing instrument 1 is demonstrated easily. FIG. 1 is a front view of a writing instrument 1 according to an embodiment of the present invention. FIG. 2 is a front sectional view of the writing instrument 1 of FIG. In the present embodiment, the writing instrument 1 is a knock-type ballpoint pen. In the present specification, as shown in FIG. 1, in the axial direction (longitudinal direction) of the writing instrument 1, the tip of the writing instrument 1, that is, the pen tip side is defined as the “front” side. The opposite side is defined as the “rear” side.

  The writing instrument 1 is connected to the front cylinder 2, the rear cylinder 3 disposed behind the front cylinder 2, the inner cylinder 4 disposed behind the rear cylinder 3, and the inner cylinder 4 so as to be swingable. The clip 5 and the first coil spring 6 that urges the clip 5 are provided. The front shaft cylinder 2, the rear cylinder 3, the inner cylinder 4 and the clip 5 are made of a resin material. In this specification, the front shaft cylinder 2, the rear shaft cylinder 3, and the inner cylinder 4 are collectively referred to as a shaft cylinder. The front barrel 2, the rear barrel 3 and the inner barrel 4, the front barrel 2 and the rear barrel 3, or the rear barrel 3 and the inner barrel 4 may be integrated.

  The writing instrument 1 includes a refill 7 disposed inside the front shaft cylinder 2 and the rear shaft cylinder 3, a second coil spring 8 that biases the refill 7 rearward, an erasing member 9 for erasing the handwriting, and an erasure And a cover member 10 that covers the member 9. The erasing member 9 and the cover member 10 are disposed at the rear end of the writing instrument 1.

  The refill 7 has an ink storage tube that stores ink, and a writing unit 71 is attached to the front end of the ink storage tube. When the cover member 10 is pressed with a finger while the writing portion 71 is immersed in the front barrel 2, the refill 7 moves forward against the urging force of the second coil spring 8, and the writing portion 71 is moved to the front barrel. 2 protrudes. On the other hand, when the cover member 10 is pressed again with a finger while the writing portion 71 protrudes from the front barrel 2, the refill 7 is retracted by the urging force of the second coil spring 8, and the writing portion 71 is moved to the front barrel 2. Immerse in.

  Hereinafter, the structure of the inner cylinder 4, the clip 5, and the 1st coil spring 6 is demonstrated in detail. FIG. 3 is a front view of the inner cylinder 4, the clip 5, and the first coil spring 6 when the clip 5 is not operated. FIG. 4 is a front view of the inner cylinder 4, the clip 5, and the first coil spring 6 when the clip 5 is being operated. 3 and 4, other parts of the writing instrument 1 are omitted. In addition, the state of FIG. 3 is equal to the state of FIG.

  The first coil spring 6 is disposed between the inner cylinder 4 and the clip 5 and biases the clip 5 so that the front end portion of the clip 5 approaches the rear shaft cylinder 3. The first coil spring 6 extends substantially perpendicular to the axial direction of the writing instrument 1. As shown in FIG. 1, when the clip 5 is not operated, the front end portion of the clip 5 comes into contact with the rear barrel 3 by the urging force of the first coil spring 6.

  On the other hand, as shown in FIG. 4, when the rear end portion of the clip 5 is operated by pressing in the axial center direction with a finger or the like, the first coil spring 6 is compressed. As a result, the clip 5 swings and the front end portion of the clip 5 is separated from the rear barrel 3. In this state, articles (paper, clothes, etc.) can be easily inserted between the clip 5 and the rear barrel 3.

  When the rear end portion of the clip 5 is released from the state where the front end portion of the clip 5 is separated from the rear barrel 3 while the article is inserted between the clip 5 and the rear barrel 3, the clip 5 is moved to the first coil spring. 6 and the front end of the clip 5 presses the article. As a result, the article is held between the clip 5 and the rear barrel 3.

  FIG. 5 is a perspective view of the inner cylinder 4, FIG. 6 is a front view of the inner cylinder 4, and FIG. 7 is a plan view of the inner cylinder 4. The inner cylinder 4 includes a front cylinder part 41 that is inserted into the rear axle cylinder 3, a rear cylinder part 42 that is disposed outside the rear axle cylinder 3, and a clip holding part 43 that holds the clip 5.

  The clip holding portion 43 is provided with two engagement protrusions 44 that are inserted into engagement holes 53a of the clip 5 described later. The engagement protrusion 44 has a substantially cylindrical shape and protrudes from the clip holding portion 43 in a direction perpendicular to the axial direction of the writing instrument 1. The clip 5 is slidably connected to the inner cylinder 4 via an engagement protrusion 44. The engaging protrusion 44 functions as a swing fulcrum when the clip 5 swings.

  The rear cylinder portion 42 is provided with a spring holding portion 45 into which the first coil spring 6 is extrapolated. The spring holding portion 45 has a substantially cylindrical shape and protrudes from the rear cylinder portion 42 to the radially outer side of the inner cylinder 4. The spring holding part 45 is divided into two parts and has a front part 45a and a rear part 45b. The front part 45a is located in front of the rear part 45b (front cylinder part 41 side).

  FIG. 8 is an enlarged front view of the spring holding portion 45. The tip of the spring holding part 45 has a tapered shape that becomes narrower toward the tip of the spring holding part 45. This facilitates extrapolation of the first coil spring 6 to the spring holding portion 45.

  On the side surface of the spring holding portion 45, a protrusion that protrudes from the spring holding portion 45 to the radially outer side of the spring holding portion 45 is provided. Specifically, two first projections 45c are provided on the side surfaces of the front portion 45a and the rear portion 45b, respectively, and one second projection 45d is provided on the side surface of the front portion 45a. The first protrusion 45 c is provided at the base end of the spring holding portion 45. On the other hand, the second protrusion 45 d is provided at a position separated from the base end of the spring holding portion 45, specifically, between the base end and the tip end of the spring holding portion 45. The second protrusion 45d is disposed at the front end of the spring holding portion 45.

  The first protrusion 45 c engages with the end portion of the first coil spring 6 that is extrapolated to the spring holding portion 45. The second protrusion 45 d engages with the first coil spring 6 when the first coil spring 6 is about to be detached from the spring holding portion 45. Therefore, the first protrusion 45 c and the second protrusion 45 d can suppress the first coil spring 6 from being detached from the spring holding portion 45, that is, the first coil spring 6 from being removed from the writing instrument 1.

  Further, when the first coil spring 6 is compressed by operating the clip 5, more force is applied to the rear end portion of the first coil spring 6, so that the front end portion of the first coil spring 6 is connected to the spring holding portion 45. It tends to float from the base end. On the other hand, in the present embodiment, the second protrusion 45 d is provided on the front portion 45 a of the spring holding portion 45. For this reason, it is possible to suppress the front end portion of the first coil spring 6 from floating from the base end of the spring holding portion 45, and further to further prevent the first coil spring 6 from coming off the spring holding portion 45. it can.

  Further, as can be seen from FIG. 7, the first protrusion 45 c and the second protrusion 45 d are separated in the circumferential direction of the spring holding portion 45. As a result, the holding force of the first coil spring 6 can be increased in a wide range in the circumferential direction of the spring holding portion 45. For this reason, it can further suppress that the 1st coil spring 6 comes off from the spring holding | maintenance part 45. FIG.

  In addition, the tip portions of the first projection 45 c and the second projection 45 d (the portion on the tip side of the spring holding portion 45) have a tapered shape that narrows toward the tip of the spring holding portion 45. For this reason, it can suppress that the mounting property to the spring holding | maintenance part 45 of the 1st coil spring 6 deteriorates with the 1st protrusion 45c and the 2nd protrusion 45d.

  The second protrusion 45d may be provided not only on the front portion 45a but also on the side surfaces of the front portion 45a and the rear portion 45b. Further, the first protrusion 45c or the second protrusion 45d may be omitted. Moreover, the spring holding part 45 may have an integral shape without being divided into the front part 45a and the rear part 45b. Also in this case, a portion located on the front side (front cylinder portion 41 side) of the spring holding portion 45 is referred to as a front portion of the spring holding portion 45. The spring holding part 45 may have a substantially polygonal column shape.

  A projection 46 is formed on the outer peripheral surface of the front cylinder portion 41. In addition, two grooves 47 extending along the axial direction of the writing instrument 1 are formed on the outer peripheral surface of the front tube portion 41 in the vicinity of the protruding portion 46. The two grooves 47 penetrate the front cylinder portion 41. The two grooves 47 are formed independently without communicating with each other. Further, the two grooves 47 are disposed on both sides of the protrusion 46 in the circumferential direction. In other words, the protrusion 46 is formed on a doubly supported beam 48 defined by two grooves 47 and supported at both ends. The protruding portion 46 is disposed at the center of the axial length of the both-end supported beam portion 48. However, it is preferable that the rear end of the protrusion 46 is disposed behind the center of the axial length of the double-supported beam 48.

  When the front tube portion 41 is inserted into the rear shaft tube 3, the projection 46 of the inner tube 4 is inserted into a through hole formed in the rear shaft tube 3, and the assembly is completed (FIG. 2). Since the two grooves 47 are formed in the vicinity of the protruding portion 46 of the inner cylinder 4, that is, the protruding portion 46 is formed in the doubly supported beam portion 48, the front cylindrical portion 41 of the inner cylinder 4 is moved to the rear. When the shaft tube 3 is inserted, the protrusion 46 comes into contact with the inner edge of the rear end opening of the rear shaft tube 3, and the both-end supported beam portion 48 is elastically deformed radially inward. Thereby, the insertion into the rear barrel 3 of the inner cylinder 4 is facilitated. In other words, by adjusting the length and shape of the two grooves 47 and adjusting the circumferential length of the both-end supported beam portion 48, that is, the width and the length in the axial direction, adjusting the elasticity of the both-end supported beam portion 48. Can do. Further, since the protrusion 46 is formed on the both-end supported beam portion 55 instead of the cantilever beam, excessive bending and creep deformation do not occur.

  9 is a perspective view of the clip 5, FIG. 10 is a front view of the clip 5, and FIG. 11 is a bottom view of the clip 5. The clip 5 includes a clip main body 51, two projecting portions 52, and two side wall portions 53 adjacent to the projecting portions 52. The projecting portion 52 projects from the clip body 51 toward the rear barrel 3 so as to contact the rear barrel 3. The plate thickness of the protruding portion 52 and the side wall portion 53 is substantially equal to the plate thickness of the clip body 51.

  The side wall 53 is provided with an engagement hole 53a into which the engagement protrusion 44 of the inner cylinder 4 is inserted. The rear end portion of the side wall portion 53 covers the side portion of the first coil spring 6. As a result, the radial movement of the first coil spring 6 can be suppressed. For this reason, it can further suppress that the 1st coil spring 6 comes off from the spring holding | maintenance part 45. FIG.

  When the clip main body 51 is attached to the inner cylinder 4, it extends along the shaft cylinder (the inner cylinder 4 and the rear shaft cylinder 3). The clip body 51 is provided with a swing restricting portion 51a and a spring support portion 51b.

  The swing restricting portion 51 a has a cylindrical shape and protrudes from the clip main body 51 toward the inner cylinder 4. FIG. 12 is a front sectional view of the inner cylinder 4, the clip 5, and the first coil spring 6 when the clip 5 is being operated. As shown in FIG. 12, the swing restricting portion 51 a abuts on the clip holding portion 43 when the clip 5 is operated, and restricts the swing range of the clip 5 when the clip 5 moves away from the rear barrel 3. To do.

  As can be seen from FIG. 11, the spring support portion 51 b has an arc shape in a cross section perpendicular to the extending direction of the first coil spring 6, and protrudes from the clip body 51 toward the inner cylinder 4. The inner diameter of the arc is substantially equal to the outer diameter of the first coil spring 6. The spring support portion 51 b is disposed on the front side of the first coil spring 6 (the pen tip side of the writing instrument 1) and supports the front end portion of the first coil spring 6. As a result, the radial movement of the first coil spring 6 can be suppressed. For this reason, it can further suppress that the 1st coil spring 6 comes off from the spring holding | maintenance part 45. FIG.

  In the present embodiment, a member for supporting the first coil spring 6 is not provided on the rear side of the first coil spring 6. For this reason, it is not necessary to greatly compress the first coil spring 6 in order to attach the first coil spring 6 to the writing instrument 1. Therefore, the mounting property of the first coil spring 6 to the writing instrument 1 can be ensured.

  Further, the height h (see FIG. 8) of the spring holding portion 45 of the inner cylinder 4 is the length of the first coil spring 6 when the clip 5 is not operated, that is, when the clip 5 is not operated. The distance between the rear cylinder portion 42 of the cylinder 4 and the clip body 51 is preferably less than ½. This makes it easy to insert the first coil spring 6 into the spring holding portion 45, and as a result, the mounting property of the first coil spring 6 to the writing instrument 1 can be improved. In the present embodiment, the height h of the spring holding portion 45 of the inner cylinder 4 is about 1/3 of the length of the first coil spring 6 when the clip 5 is not operated.

  The protruding portion 52 of the clip 5 is connected to the side wall portion 53 and extends substantially parallel to the axial direction of the writing instrument 1. FIG. 13 is a left side view of the clip 5. FIG. 14 is an enlarged view of a portion A in FIG. 13 when the protruding portion 52 is in contact with the rear barrel 3.

  The protruding part 52 is formed with a parting line PL. The clip 5 is formed by using a three-way split mold that opens in the left, right, and lower three directions in the plane of FIG. The block that opens downward is a slide mold used to mold the inner surface of the clip 5 such as the swing restricting portion 51a and the spring support portion 51b. The parting line PL shown in FIG. 14 is a mating surface of a block opened downward and a block opened left.

  A linear protrusion is left on the parting line PL. Further, burrs are likely to occur at positions where the parting lines PL are formed. For this reason, when the parting line PL or the burr contacts the rear barrel 3, the outer surface of the rear barrel 3 may be damaged. In the present embodiment, the outer surface of the rear barrel 3 is subjected to surface treatment such as transfer printing, painting, or decoration. For this reason, the outer surface of the rear barrel 3 is easily damaged by the protruding portion 52 of the clip 5. However, in this embodiment, the parting line PL is formed in a portion that does not contact the rear barrel 3 of the protruding portion 52. For this reason, it can suppress that the burr | flash which generate | occur | produced in the parting line PL contacts the rear-shaft cylinder 3, and can suppress that the outer surface of the rear-shaft cylinder 3 is damaged by the protrusion part 52 by extension.

  Further, the inner end 52a and the outer end 52b of the protrusion 52 have an R shape. The inner end 52 a of the protrusion 52 corresponds to a portion that contacts the rear barrel 3 of the protrusion 52. For this reason, since the part which contacts the rear-shaft cylinder 3 is R shape, it can suppress that the outer surface of the rear-shaft cylinder 3 is damaged by the protrusion part 52. FIG. In this specification, the side close to the axis of the writing instrument 1 in the direction perpendicular to the axial direction of the writing instrument 1 and the protruding direction of the protruding portion 52 (the horizontal direction in FIGS. 13 and 14) is defined as the “inside” side. The side away from the axis of the writing instrument 1 is defined as the “outside” side.

  In the present embodiment, the straight portion 52d is between the R shape of the inner end portion 52a and the parting line PL. As a result, the parting line PL can be separated from the rear barrel 3, and the parting line PL and the burr generated on the parting line PL can be further suppressed from coming into contact with the rear barrel 3.

  In the present embodiment, a step 52c is provided in the parting line PL. This suppresses the burr from protruding from the bottom surface of the protruding portion 52 (the surface close to the axis of the writing instrument 1 in the protruding direction of the protruding portion 52). Further, the step 52 c faces the side opposite to the portion that contacts the rear barrel 3 of the protruding portion 52 in the direction perpendicular to the axial direction of the writing instrument 1 and the protruding direction of the protruding portion 52. Thus, it is possible to suppress the stepped portion 52c from coming into contact with the rear barrel 3 and damaging the rear barrel 3. In the present embodiment, the height of the step 52c is 20 μm to 40 μm.

  The two protrusions 52 are symmetrical with respect to the XX plane of FIG. Therefore, a parting line that is a mating surface of the block that opens downward and the block that opens to the right is also formed on the other protrusion 52 not shown in FIG. 14, and a step is provided in the parting line.

  As mentioned above, although preferred embodiment which concerns on this invention was described, this invention is not limited to the said embodiment, A various correction and change can be given within description of a claim. For example, the writing instrument 1 may be another writing instrument such as a mechanical pencil.

  Further, the spring holding portion 45 may be provided on the clip 5 or the shaft cylinder (inner cylinder 4) and the clip 5. That is, the spring holding portion 45 is provided on at least one of the shaft cylinder (inner cylinder 4) and the clip 5. Further, the spring support portion 51b may be omitted or provided on the shaft cylinder (inner cylinder 4). Moreover, the number of the protrusion parts 52 of the clip 5 may be one or three or more.

  The refill 7 may contain a thermochromic ink containing a thermochromic color material. In this case, the writing instrument 1 is a thermochromic writing instrument, and the handwriting of the writing instrument 1 can be discolored by frictional heat generated when it is rubbed by a friction body as the erasing member 9.

  Here, the thermochromic ink means that a predetermined color (first color) is maintained at room temperature (for example, 25 ° C.), and when the temperature is raised to a predetermined temperature (for example, 60 ° C.), the color changes to another color (second color). The ink has a property of returning to the original color (first color) when cooled to a predetermined temperature (for example, −20 ° C.). In the writing instrument 1 using the thermochromic ink, the second color is made colorless and the stroke drawn with the first color (for example, red) is heated to make it colorless, which is herein referred to as “erasing”. . Accordingly, the frictional body rubs against the writing surface on which the drawn line is written to generate frictional heat, thereby changing the drawn line to colorless, that is, erasing it. Of course, the second color may be a color other than colorless. Moreover, it is preferable that the temperature difference from the first color to the second color is 70 ° C. or more.

  As the thermochromic microcapsule pigment that becomes a thermochromic color material, those that change color due to heat such as frictional heat, for example, those that have a function from colored to colorless, colored to colored, colorless to colored, etc. There are no particular limitations, and various types can be used. Examples include microencapsulated thermochromic compositions containing at least a leuco dye, a developer, and a color change 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, from the viewpoint of obtaining an ink having excellent color development characteristics, conventionally known ones such as triphenylmethane, spiropyran, fluoran, diphenylmethane, rhodamine lactam, indolylphthalide, leucooramine, It can be used alone (one kind) or in a mixture of two or more kinds (hereinafter simply referred to as “at least one kind”).

  Specifically, 6- (dimethylamino) -3,3-bis [4- (dimethylamino) phenyl] -1 (3H) -isobenzofuranone, 3,3-bis (p-dimethylaminophenyl) -6 -Dimethylaminophthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1 -Ethyl-2-methylindol-3-yl) -4-azaphthalide, 1,3-dimethyl-6-diethylaminofluorane, 2-chloro-3-methyl-6-dimethylaminofluorane, 3-dibutylamino-6 -Methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-xylidinofluor Lan, 2- (2-chloroanilino) -6-dibutylaminofluorane, 3,6-dimethoxyfluorane, 3,6-di-n-butoxyfluorane, 1,2-benz-6-diethylaminofluorane, 1 , 2-Benz-6-dibutylaminofluorane, 1,2-Benz-6-ethylisoamylaminofluorane, 2-methyl-6- (Np-tolyl-N-ethylamino) fluorane, 2- (N -Phenyl-N-methylamino) -6- (Np-tolyl-N-ethylamino) fluorane, 2- (3'-trifluoromethylanilino) -6-diethylaminofluorane, 3-chloro-6 -Cyclohexylaminofluorane, 2-methyl-6-cyclohexylaminofluorane, 3-di (n-butyl) amino-6-methoxy-7-anilinofluorane 3,6-bis (diphenylamino) fluorane, methyl-3 ′, 6′-bisdiphenylaminofluorane, chloro-3 ′, 6′-bisdiphenylaminofluorane, 3-methoxy-4-dodecoxystyrino Quinoline, etc.

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

  The developer that can be used is a component having the ability to develop the leuco dye, such as a phenol resin compound, a salicylic acid metal chloride, a salicylic acid resin metal salt compound, a solid acid compound, etc. Is mentioned.

  Specifically, o-cresol, tertiary butyl catechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, hexafluorobisphenol, p N-butyl hydroxybenzoate, n-octyl p-hydroxybenzoate, resorcin, dodecyl gallate, 2,2-bis (4′-hydroxyphenyl) propane, 4,4-dihydroxydiphenyl sulfone, 1,1-bis (4′-hydroxyphenyl) ethane, 2,2-bis (4′-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, 1-phenyl-1,1-bis (4′-hydroxy Phenyl) ethane, 1,1-bis ( 4′-hydroxyphenyl) -3-methylbutane, 1,1-bis (4′-hydroxyphenyl) -2-methylpropane, 1,1-bis (4′-hydroxyphenyl) n-hexane, 1,1-bis (4′-hydroxyphenyl) n-heptane, 1,1-bis (4′-hydroxyphenyl) n-octane, 1,1-bis (4′-hydroxyphenyl) n-nonane, 1,1-bis (4 '-Hydroxyphenyl) n-decane, 1,1-bis (4'-hydroxyphenyl) n-dodecane, 2,2-bis (4'-hydroxyphenyl) butane, 2,2-bis (4'-hydroxyphenyl) ) Ethyl propionate, 2,2-bis (4′-hydroxyphenyl) -4-methylpentane, 2,2-bis (4′-hydroxyphenyl) hexafluoropropane, 2 2- bis (4'-hydroxyphenyl) n- heptane, 2,2-bis least one such (4'-hydroxyphenyl) n- nonane and the like.

  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 part by mass of the leuco dye described above. It is preferable to select within a range of about 100 parts by mass.

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

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

  The amount of the color-change temperature adjusting agent used may be appropriately selected according to the desired hysteresis width and color density at the time of color development, and is not particularly limited, but is usually based on 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, the developer, and the color change temperature adjusting agent so that the average particle diameter is 0.2 to 3 μm. Can be manufactured. Examples of the microencapsulation method include interfacial polymerization method, interfacial polycondensation method, in situ polymerization method, liquid curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melt dispersion cooling method, air A suspension coating method, a spray drying method, etc. can be mentioned, and can be appropriately selected according to the application.

  For example, in a phase separation method from an aqueous solution, a leuco dye, a developer, and a color change temperature adjusting agent are heated and melted, then charged into an emulsifier solution, heated and stirred to disperse into oil droplets, and then as a capsule film agent, Use resin raw materials, for example, gradually add amino resin solution, isocyanate resin solution, etc., and continue to react to prepare, then filter this dispersion to produce the desired thermochromic microcapsule pigment be able to.

  The content of these leuco dyes, developer, and color change temperature adjusting agent varies depending on the type of leuco dye, developer, color change temperature adjusting agent used, microencapsulation method, etc. The developer is 0.1 to 100 developer and 1 to 100 color changing temperature adjusting agent in mass ratio. Moreover, a capsule membrane agent is 0.1-1 by mass ratio with respect to the capsule content.

  The thermochromic microcapsule pigment is a combination of the above-described leuco dye, color developer, and color change temperature adjusting agent, and the amount, color development temperature of each color (for example, color development at 0 ° C. or higher), decolorization temperature ( For example, it is possible to set the color erasing at 50 ° C. or higher) to a suitable temperature, and it is preferable that the color changes from colored to colorless by 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 writing property. As a urethane resin, the compound of isocyanate and a polyol is mentioned, for example. As an epoxy resin, the compound of an epoxy resin and an amine is mentioned, for example. Examples of amino resins include melamine resins, urea resins, and benzoguanamine resins. 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 drawn line density.

  The average particle size of the thermochromic microcapsule pigment is low in color, color developability, easy decoloring, stability, fluidity in ink, and adverse effects on writing properties. From the viewpoint of compatibility with the microcapsule pigment, it is preferably 0.2 to 5 μm, and more preferably 0.3 to 3 μm. The “average particle diameter” defined here is a value obtained by measuring the average particle diameter (50% diameter) with a particle size analyzer [Microtrac HRA9320-X100 (Nikkiso Co., Ltd.)] (refractive index 1.8). It is.

  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, the writing property is deteriorated, the dispersion stability of the thermochromic microcapsule pigment is lowered, and the ink is caused by vibration. Back is likely to occur, which is not preferable. 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 ratio or more, the above-described influence tends to become more prominent. In addition, although the microcapsule pigment having an average particle diameter range (0.2 to 5 μm) described above varies depending on the microencapsulation method, in the phase separation method from an aqueous solution, stirring when the microcapsule pigment is produced. It can be prepared by suitably combining 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 outside this range, the dispersion stability of the microcapsule pigment tends to be lowered. In addition, microcapsule pigments having a specific gravity exceeding 1.3 are liable to generate ink back due to vibration.

  In the water-based ink composition for writing instruments, in addition to the thermochromic microcapsule pigment, the balance is water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.), and other writing instruments (ballpoint pens) Depending on the purpose of use, for marking pens, etc., water-soluble organic solvents, thickeners, lubricants, rust preventives, antiseptics or antibacterial agents may be appropriately contained within a range that does not impair the effect. it can.

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

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

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

  Of these, it is preferable to use polysaccharides. Polysaccharides tend to be less susceptible to fluidity due to vibrations due to their rheological properties, and problems such as poor writing due to ink back are less likely to occur. Xanthan gum is particularly preferable because it is excellent in balance with other properties required for writing instrument inks.

  Lubricants include fatty acid esters of polyhydric alcohols, higher fatty acid esters of sugars, polyoxyalkylene higher fatty acid esters, alkyl phosphate esters, alkyl sulfonates of higher fatty acid amides, alkyl allyl sulfones, which are also used in pigment surface treatment agents. Examples thereof include acid salts, polyalkylene glycol derivatives, fluorine-based surfactants, and polyether-modified silicones. Examples of the rust inhibitor include benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, and saponins. Examples of the antiseptic or antibacterial agent include phenol, sodium omadin, sodium benzoate, and benzimidazole compounds.

  In order to produce this water-based ink composition for writing instruments, a conventionally known method can be employed. For example, in addition to the thermochromic and photochromic microcapsule pigments, a predetermined amount of each component in the water is used. It is obtained by mixing and stirring and mixing with a homomixer or a stirrer such as a disper. Furthermore, if necessary, coarse particles in the ink composition may be removed by filtration or centrifugation.

The viscosity value of the aqueous ink composition for a writing instrument 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, the ink can be excellent in writability and stability over time. Furthermore, S = αD ⁿ (where 1>n> 0) (S is a shear stress (dyn / cm ² ), D is a shear rate (s ⁻¹ ), α is a 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 to prevent the occurrence of ink back.

  The surface tension of the aqueous 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 ink wettability becomes appropriate, and the occurrence of ink back can be prevented.

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

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

  Specific polybutenes that can be used include, for example, the commercially available products Nissan Polybutene 200N, Polybutene 30N, Polybutene 10N, Polybutene 5N, Polybutene 3N, Polybutene 015N, Polybutene 06N, Polybutene 0N (above, manufactured by NOF Corporation), Polybutene HV-15 (made by Nippon Petrochemical Co., Ltd.), 35R (made by Idemitsu Kosan Co., Ltd.), etc. are mentioned.

  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, (P-10000, P-37500) (manufactured by Matsumura Oil Co., Ltd.).

  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). Chemical Co., Ltd.).

  These nonvolatile or hardly 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 phosphate phosphate, fine particle silica, polystyrene-polyethylene / butylene rubber-polystyrene block copolymer, polystyrene-polyethylene / propylene rubber-polystyrene block copolymer, and hydrogenated styrene. -Butadiene rubber, block copolymer of styrene-ethylenebutylene-olefin crystal, block copolymer of olefin crystal-ethylenebutylene-olefin crystal, acetoalkoxyaluminum dialchelate, and the like can be used, and these can be used alone or in combination.

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

  Examples of a commercially available block copolymer of polystyrene-polyethylene / butylene rubber-polystyrene include Kraton GFG-1901X, Kraton GG-1650 (manufactured by Shell Japan), Septon 8007, Septon 8004 (manufactured by Kuraray), and the like. Is mentioned. Furthermore, as a preferable commercial item of the block copolymer of polystyrene-polyethylene / propylene rubber-polystyrene, Kraton GG-1730 (manufactured by Shell Japan Co., Ltd.), Septon 2006, Septon 2063 (manufactured by Kuraray Co., Ltd.) and the like can be mentioned.

  Examples of preferable commercially available hydrogenated styrene-butadiene rubber include DYNARON 1320P, DYNARON 1321P (manufactured by JSR Corporation), Tuftec H1041, Tuftech H141 (manufactured by Asahi Kasei Kogyo Co., Ltd.), and the like.

  DYNARON 4600P (manufactured by JSR) and the like are mentioned as preferable commercial products of the block copolymer of styrene-ethylene butylene-olefin crystals, and DYNARON 6200P and DYNARON 6201B ( JSR) and the like.

  Plenact AL-M (manufactured by Ajinomoto Fine-Techno Co., Ltd.) and the like are preferable as a commercially available product of acetoalkoxy aluminum dial chelate.

  Among these thickeners, the use of thermoplastic olefin elastomers such as block copolymers of styrene-ethylene butylene-olefin crystals and block copolymers of olefin crystals-ethylene butylene-olefin crystals is preferred.

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

  Here, tan δ is a value meaning loss elastic modulus / storage elastic modulus, and conventionally, an average value of tan δ values measured for each frequency while increasing exponentially in the frequency region “1 to 63 rad / s”. Has been known to be preferably 1.0 or less. In the present invention, when the average value of the tan δ values measured for each frequency at 1 to 63 rad / s is 1.0 or more, it is possible to absorb vibration and prevent occurrence of ink back.

  Rubber elastic materials such as thermosetting rubber such as silicone rubber, nitrile rubber, ethylene propylene rubber, ethylene propylene diene rubber, and thermoplastic elastomer such as styrene elastomer, olefin elastomer, polyester elastomer, etc. A mixture of two or more rubber elastic materials and a mixture of a rubber elastic material and a synthetic resin can be used. This is a wear test (ASTM D1044) defined in JIS K7204 and a load of 9.8 N, 1000 rpm environment. Below, it comprises so that the Taber abrasion amount in the abrasion wheel H-22 of a Taber abrasion tester may be less than 15 mg, and forms a friction body.

  Further, the friction body preferably has a durometer A hardness of 70 or more as defined in JIS K6203. Thereby, a predetermined hardness can be ensured and a more stable rubbing operation can be achieved. Note that the friction body can also be applied as a touch pen or a stylus pen, and may impart conductivity.

  Further, by setting the luminance value of the friction body to 70 or less, the contamination on the surface due to the use of the friction body can be made inconspicuous.

  The brightness value uses an HLS color space system with a range of 0 to 100, and measures the surface of the friction body using a measuring device such as a general-purpose color difference meter (TC-8600A, manufactured by Tokyo Denshoku Co., Ltd.). Is required.

  FIG. 15 is a front view of another form in which the clip 105 is connected to the inner cylinder 104.

  FIG. 16 is a perspective view of the inner cylinder 104. Since the inner cylinder 104 is similar to the inner cylinder 4 described with reference to FIGS. 5 to 7, only different points will be described. The inner cylinder 104 includes a front cylinder part 41 that is inserted into the rear axle cylinder 3, a rear cylinder part 42 that is disposed outside the rear axle cylinder 3, and a clip holding part 143 that holds the clip 105. A plurality of recesses 143a are formed in the clip holding portion 143 of the inner cylinder 104 in order to suppress molding shrinkage during molding by the mold. Further, the swing restricting portion 143b is in contact with the clip 105 when the clip 105 is operated, and the swing restricting portion 143b restricts the swing range of the clip 105 when the clip 105 moves away from the rear barrel 3. Is formed. Therefore, as will be described later, the clip 105, unlike the above-described clip 5, does not have a configuration corresponding to the swing restricting portion.

  The clip holding portion 143 is provided with two engagement protrusions 144 that are inserted into the engagement holes 53a of the clip 105. The engagement protrusion 144 has a substantially cylindrical shape and protrudes from the clip holding portion 143 in a direction perpendicular to the axial direction of the writing instrument 1. The clip 105 is slidably connected to the inner cylinder 104 via the engaging protrusion 144. The engaging protrusion 144 functions as a swing fulcrum when the clip 105 swings. Accordingly, the swing restricting portion 143b is provided at least behind the engaging protrusion 144 in the axial direction.

  A fitting surface 144 a is provided on an outer portion of the end face of the engagement protrusion 144, that is, a portion on the clip 105 side. The height of the engaging protrusion 144 on the fitting surface 144a is formed lower than the inner portion of the end face of the engaging protrusion 144. The fitting surfaces 144a of the engaging protrusions 144 are parallel to each other. The clip holding part 143 is further provided with two fitting protrusions 149. The fitting protrusion 149 has a substantially cylindrical shape. The fitting protrusion 149 protrudes from the clip holding portion 143 in a direction perpendicular to the axial direction of the writing instrument 1 and is disposed in front of the corresponding engaging protrusion 144.

  FIG. 17 is a perspective view of the clip 105. The clip 105 differs from the clip 5 described with reference to FIGS. 9 to 11 only in that it does not have the swing restricting portion 51a and the spring support portion 51b.

  FIG. 18 is a front view of a state in which the clip 105 is temporarily fastened to the inner cylinder 104 before being connected. At the time of assembly, first, the clip 105 is temporarily fixed to the inner cylinder 104 (FIG. 18). Next, by pressing the clip 105 in the axial center direction, the engagement protrusion 144 of the inner cylinder 104 is elastically deformed so as to widen the interval between the opposing side wall portions 53. As a result, the engagement protrusion 144 of the inner cylinder 104 snaps into the engagement hole 53a of the clip 105, and the clip 105 is coupled to the inner cylinder 104 (FIG. 15).

  Temporary fastening will be described with reference to FIGS. 19 and 20. 19 and 20, the lower side is the axial center direction. FIG. 19 is a cross-sectional view of a state before the clip 105 is temporarily fastened to the inner cylinder 104, and is a cross-sectional view similar to FIG. 20 is a cross-sectional view taken along line LL in FIG. Temporary fastening is an alignment operation before the clip 105 is connected. In other words, the temporary fastening means that the temporarily fastened clip 105 is tilted with respect to the inner cylinder 104 with such a force that the clip 105 does not come off due to its own weight or the like without an external force such as an assembly operator's hand. It means that it is attached stably.

  Temporary fastening is performed by sandwiching the fitting surface 144a of the engaging projection 144 and the end surface of the fitting projection 149 between the opposing sidewall portions 53 of the clip 105 by a restoring force due to elastic deformation of the sidewall portion 53. . Therefore, in FIG. 19 which is a state before temporary fixing, the distance X between the fitting surfaces 144a of the engaging protrusion 144 is slightly smaller than the distance Y between the opposing side wall portions 53 before temporary fixing at the corresponding position. Just big. In other words, the width of the inner surface of the clip 105 is shorter than the width of the side surface of the clip holding portion 143. For example, the relationship between the distance X between the fitting surfaces 144a and the distance Y between the side wall portions 53 is preferably 0.01 <X−Y <0.05 mm. Moreover, in FIG. 20 which is in the temporarily fastened state, the contact length between the fitting surface 144a and the side wall portion 53, that is, the radial length Z is preferably 0.5 to 3 mm. The temporary fastening may be performed by a frictional force between the surface of the side wall portion 53, the fitting surface 144a of the engaging projection 144, and the end surface of the fitting projection 149. The fitting protrusion 149 may be omitted.

  Temporary fastening can be easily performed by lightly fitting the clip 105 to the clip holding portion 143 of the inner cylinder 104, particularly the engagement protrusion 144, that is, by light press-fitting, so that the clip 105 can be quickly and accurately connected. It can be performed. As a result, assembly productivity can be improved. Further, the clip 105 can be connected to the inner cylinder 104 without damaging the engaging protrusion 144 of the inner cylinder 104.

  In addition, as long as a clip is temporarily fixed, the position and shape of the fitting surface in an engagement protrusion can be arbitrarily employ | adopted. Therefore, the two fitting surfaces may be inclined surfaces that are not parallel to each other but are inclined so as to be separated from each other toward the inside.

DESCRIPTION OF SYMBOLS 1 Writing instrument 2 Front axis | shaft cylinder 3 Rear axis cylinder 4 Inner cylinder 5 Clip 6 1st coil spring 45 Spring holding part 45c 1st protrusion 45d 2nd protrusion 51 Clip main body 51b Spring support part 52 Projection part PL Parting line

Claims (4)

A shaft cylinder, a clip that is swingably connected to the shaft cylinder, and a coil spring that is disposed between the shaft cylinder and the clip and biases the clip, and the coil spring is extrapolated. In the writing instrument, the spring holding portion is provided on at least one of the shaft cylinder and the clip.
A writing instrument, wherein a projection is provided on a side surface of the spring holding portion.   The protrusion includes a first protrusion provided at a base end of the spring holding portion and a second protrusion provided at a position spaced from the base end of the spring holding portion, and the first protrusion and the second protrusion The writing instrument according to claim 1, wherein the protrusions are spaced apart in a circumferential direction of the spring holding portion.   The writing instrument according to claim 1 or 2, wherein a spring support portion that is disposed on a front side of the coil spring and supports a front end portion of the coil spring is provided in the shaft cylinder or the clip.   The writing instrument according to any one of claims 1 to 3, further comprising a clip holding portion that holds a clip, wherein a width of an inner surface of the clip is shorter than that of a side surface of the clip holding portion.

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