JP6678443B2 - Knock-type writing instrument - Google Patents

Description

  The present invention relates to a knock-type writing instrument.

  A refill containing ink by performing a knocking operation that has an operating portion at the rear end of the barrel and presses the operating portion forward against the urging force of a spring disposed in the barrel, i.e., writing 2. Description of the Related Art A knock-type writing instrument, which is a so-called knock type, in which a writing state in which a writing portion as a pen tip of a body protrudes from the tip of a barrel and a non-writing state in which the writing section is immersed in the barrel is switched.

  Generally, in a knock-type writing instrument, bubbles may be generated in ink in the refill due to an impact applied to the refill when switching from the writing state to the non-writing state. That is, when switching from the writing state to the non-writing state, the refill moves rearward vigorously by the urging force of the spring, and an impact is applied when the refill stops. In particular, when low-viscosity ink or shear-thinning ink is contained in the refill, the ink retreats due to the impact, and air may enter the refill from the writing portion. In this case, bubbles may be generated in the ink, which may cause poor writing. (The phenomenon that air enters during refilling due to ink receding is hereinafter referred to as “ink back”.)

  Therefore, in the knock-type writing instrument described in Patent Literature 1, an elastic body is disposed in a shaft cylinder behind the refill in order to absorb the impact of the refill moved rearward vigorously by the urging force of the spring.

JP-A-8-164697

  However, in Patent Literature 1, since the elastic body is disposed behind the refill, it is necessary to secure a space corresponding to the volume of the elastic body in the barrel, and therefore, it is necessary to shorten the total length of the refill. . As a result, the amount of ink that can be stored is reduced, and the writable distance is shortened. Also, the impact at the time of switching to the non-writing state is absorbed when the refill comes close to the retreat limit position, so that the kinetic energy is in the highest state. Therefore, no matter how much the refill is absorbed by the elastic body, the refill receives a considerable impact.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a knock-type writing instrument that can reduce an impact applied to a refill when switching to a non-writing state by a simple mechanism.

  According to one aspect of the present invention, a barrel, a writing body disposed in the barrel, an elastic member for biasing the writing body backward, and a biasing force of the elastic member at the time of knocking operation. A knock-type writing instrument comprising an operating unit pressed against the front side of the writing body, the outer surface of the writing body, when the writing body is retracted by a knocking operation, cooperating with the barrel, the writing body of the writing body A knock-type writing instrument is provided, which is provided with a braking unit that performs braking.

  According to another aspect, the braking portion has a protrusion.

  According to another aspect, an abutting portion that abuts on the projection is provided on an inner peripheral surface of the barrel.

  According to another aspect, the contact portion is a protrusion formed in an annular shape on the inner peripheral surface of the barrel.

  According to another aspect, the braking unit is a separate tubular member that is detachable from the writing body.

  According to another aspect, a plurality of ribs holding the writing body are formed on the inner peripheral surface of the tubular member.

  According to the aspect of the present invention, a common effect is obtained in which the impact applied to the refill when switching to the non-writing state can be reduced by a simple mechanism. In addition, it is possible to prevent the occurrence of ink back.

FIG. 2 is a partial cross-sectional view of the writing state of the knock-type writing instrument according to the first embodiment of the present invention. FIG. 2 is an enlarged sectional view of a distal end portion of the knock-type writing instrument of FIG. 1 in a writing state. FIG. 2 is an enlarged cross-sectional view of a distal end portion of the knock-type writing instrument of FIG. 1 in a non-writing state. It is a perspective view of the braking member of the knock-type writing instrument of FIG. FIG. 5 is a longitudinal sectional view of the braking member of FIG. 4. It is a fragmentary sectional view of a writing state of a knock type writing implement by a 2nd embodiment of the present invention. It is an expanded sectional view of the part A of FIG. FIG. 7 is a perspective view of a braking member of the knock-type writing instrument of FIG. 6. FIG. 9 is a longitudinal sectional view of the braking member of FIG. 8.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Corresponding components are denoted by common reference symbols throughout the drawings.

  FIG. 1 is a partial cross-sectional view of a writing state of the knock-type writing instrument 1 according to the first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a tip portion of the knocking-type writing instrument 1 of FIG. 1 in a writing state. FIG. 3 is an enlarged cross-sectional view of the distal end of the knock-type writing instrument 1 in FIG. 1 in a non-writing state. The knock-type writing instrument 1 includes a barrel 2 which is a tubular member formed in a tubular shape, an operation unit 3 provided at a rear end of the barrel 2, and a refill 4 which is a writing body having a writing unit 4 a. And In the present specification, in the axial direction of the knock-type writing instrument 1, the writing portion 4a side is defined as a "front" side, and the opposite side to the writing portion 4a is defined as a "rear" side.

  The refill 4 is urged rearward by a spring 5 which is an elastic member disposed in the barrel 2. The knock type writing instrument 1 has a well-known knock mechanism. By performing a knocking operation of pressing the operation unit 3 forward against the urging force of the spring 5, the writing state in which the writing unit 4 a of the refill 4 protrudes from the tip of the barrel 2 and the writing unit 4 a Is switched to a non-written state immersed in the.

  The operation unit 3 includes a cover member 6 exposed to the outside, and an erasing member (not shown) disposed inside the cover member 6 and covered by the cover member 6. By using the erasing member, the handwriting by the knock-type writing instrument 1 can be erased. Note that the operation unit 3 itself may be configured as an erasing member.

  The refill 4 includes the above-described writing section 4a, a tubular refill main body 4b, and a joint member 4c that connects the writing section 4a and the tubular refill main body 4b. A braking member 10, which is a tubular member, is provided as a braking portion on the tip of the refill 4, that is, on the outer peripheral surface of the joint member 4 c.

  FIG. 4 is a perspective view of the braking member 10 of the knock-type writing instrument 1 of FIG. 1, and FIG. 5 is a longitudinal sectional view of the braking member 10 of FIG. The braking member 10 is provided with respect to the refill 4 so that the left side is the front side of the knock-type writing instrument 1 and the right side is the rear side of the knock-type writing instrument 1 in FIG.

  An annular flange 11 is formed at the rear end of the outer peripheral surface of the braking member 10. Four protrusions 12 are formed on the outer peripheral surface of the flange portion 11 so as to be evenly arranged in the circumferential direction. Four ribs 13 are formed on the inner peripheral surface of the flange portion 11 so as to protrude inward in the radial direction and are arranged uniformly along the circumferential direction. In the rear end portion of the braking member 10, that is, in the vicinity of the flange portion 11, a thin portion 14 thinner than the rib 13 and a connecting portion 15 connecting the rib 13 and the thin portion 14 are formed. Further, the protrusion 12 is formed on the outer peripheral surface of the flange portion 11 corresponding to the thin portion 14.

  The rib 13 has a holding surface 13 a configured to guide the refill 4 inserted or press-fitted from the rear end opening of the braking member 10. A guide surface 13b that is oblique to the center axis is formed in the portion of the rib 13 near the rear end opening of the braking member 10. When inserting the refill 4, the writing surface 4a of the refill 4 is guided by the guide surface 13b. The front end surface of the rib 13 has a spring support surface 13c perpendicular to the central axis.

  The flange portion 11 has flexibility with respect to a radial force by forming the thin portion 14 and the connection portion 15. Therefore, when the refill 4 is provided on the braking member 10, the thin portion 14 and the connection portion 15 can be elastically deformed radially outward so that the rib 13 holds the refill 4 firmly, and can be expanded. Further, as described later, when the braking member 10 brakes the refill 4, the protrusion 12 can move inward in the radial direction due to the elastic deformation of the thin portion 14 and the connection portion 15.

  The braking member 10 will be described in more detail with reference to FIGS. 2 and 3 again. The braking member 10 is provided at a position where its rear end surface contacts the step 4 d of the joint member 4 c of the refill 4. The front end of the spring 5 is supported by a step 2 a formed on the inner surface of the barrel 2, and the rear end of the spring 5 is supported by a spring support surface 13 c of the braking member 10. That is, the refill 4 is urged rearward by the spring 5 via the braking member 10. An annular protrusion 7 is formed on the inner peripheral surface of the barrel 2 as a contact portion that contacts the protrusion 12 of the braking member 10.

  In the writing state of the knock-type writing instrument 1 shown in FIG. 2, when a knocking operation for pressing the operation unit 3 is performed, the refill 4 moves rearward vigorously by the urging force of the spring 5. When the refill 4 moves backward, the projection 12 of the braking member 10 and the annular projection 7 of the barrel 2 come into contact with each other. In other words, the position of the annular projection 7 of the barrel 2 in the axial direction is set so that the projection 12 of the braking member 10 and the annular projection 7 of the barrel 2 abut when the refill 4 is retracted. The size of the protrusion 12 or the annular protrusion 7 of the barrel 2 is set.

  When the projection 12 of the braking member 10 abuts on the annular projection 7 of the barrel 2, the shape of the projection 12 and the annular projection 7, that is, the curved shape, causes the projection 12 of the braking member 10 to be radially inward. The power of increases. At this time, the thin portion 14 and the connection portion 15 of the braking member 10 are elastically deformed in accordance with the retreat of the refill 4, so that the projection 12 of the braking member 10 gets over the annular projection 7 of the barrel 2 while sliding. Move backward. The resistance, that is, the frictional force caused by the sliding of the projection 12 of the braking member 10 against the annular projection 7 of the barrel 2 reduces the retreat of the refill 4. As a result, the kinetic energy of the refill 4 is reduced, and the impact that the refill 4 finally receives is reduced. Therefore, it is possible to minimize the occurrence of problems such as poor writing due to the impact.

  The spring characteristics and arrangement of the spring 5 are selected such that the refill 4 is urged against the frictional force described above, and the knock-type writing instrument 1 can be switched from the writing state to the non-writing state.

  In the non-writing state of the knock-type writing instrument 1, the distance between the front end face of the barrel 2 and the tip of the writing portion 4a in the axial direction is X, and the axial direction between the projection 12 of the braking member 10 and the annular projection 7 of the barrel 2 , It is preferable that X> Y. Conversely, in the case of X <Y, if the refill 4 is stopped because the projection 12 of the braking member 10 cannot get over the annular projection 7 of the shaft cylinder 2 when the refill 4 is retracted, the writing section 4a Are exposed from the shaft cylinder 2. As a result, when the knock-type writing instrument 1 is put in a pocket or the like, the clothes may be stained.

  FIG. 6 is a partial cross-sectional view of a writing state of the knock-type writing instrument 20 according to the second embodiment of the present invention, and FIG. 7 is an enlarged cross-sectional view of a part A of FIG. The knocking writing instrument 20 has another braking member 30 instead of the braking member 10 of the knocking writing instrument 1 according to the first embodiment described above. That is, in the knock-type writing instrument 20, a braking member 30, which is a cylindrical member, is detachably attached to the outer peripheral surface of the refill main body 4b of the refill 4 instead of the joint member 4c at the tip of the refill 4. I have.

  Another annular projection 8 is formed on the inner peripheral surface of the barrel 2 as an abutting portion that abuts on a projection 33 of the braking member 30 described below. The rest of the configuration of the knock-type writing instrument 20 is the same as that of the knock-type writing instrument 1 of the first embodiment, and a description thereof will not be repeated. Note that the braking member 30 of the present embodiment can be used together with the braking member 10 of the first embodiment in one knock-type writing instrument.

  FIG. 8 is a perspective view of the braking member 30 of the knock-type writing instrument 20 of FIG. 6, and FIG. 9 is a longitudinal sectional view of the braking member 30 of FIG. The braking member 30 is attached to the refill 4 such that the left side is the front side of the knock-type writing instrument 20 and the right side is the rear side of the knock-type writing instrument 20 in FIG.

  The outer peripheral surface of the braking member 30 has two claw portions 32 defined by U-shaped through grooves 31 when viewed from the side with the front side of the braking member 30 facing upward. The two claws 32 are arranged to face each other on the outer peripheral surface. At the rear end of the outer surface of the claw portion 32, a projection 33 is formed along the edge of the rear end. That is, the braking member 30 has two protrusions 33. An annular flange portion 34 is formed at the front end of the outer peripheral surface of the braking member 30. The front end of the claw 32 is connected to the flange 34. Since the claw portion 32 can be elastically deformed outward and inward in the radial direction from a connection point with the flange portion 34, the projection 33 of the claw portion 32 can also move inward in the radial direction.

  Four ribs 35 are formed on the inner peripheral surface of the braking member 30 along the axial direction. The rib 35 has a holding surface 35 a configured to hold the refill 4 inserted from the rear end opening of the braking member 30. The rib 35 near the rear end opening of the braking member 30 has a guide surface 35b that is inclined with respect to the center axis. When the refill 4 is inserted, the refill 4 is guided by the guide surface 35b.

  The braking member 30 reduces the retreat of the refill 4 in the same manner as the braking member 10 of the first embodiment described above. That is, when the refill 4 is retracted, the projection 33 of the braking member 30 and the annular projection 8 of the barrel 2 come into contact with each other. In other words, the position of the annular projection 8 of the barrel 2 in the axial direction is set such that the projection 33 of the braking member 30 and the annular projection 8 of the barrel 2 abut when the refill 4 is retracted. The size of the projection 33 or the annular projection 8 of the barrel 2 is set. Further, the relationship between X and Y described with reference to FIG. That is, if the axial distance between the projection 33 of the braking member 30 and the annular projection 8 of the barrel 2 is Z, it is preferable that X> Z.

  When the refill 4 is retracted, the claw portion 32 is elastically deformed in accordance with the retraction of the refill 4, so that the projection 33 of the braking member 30 moves rearward so as to get over while sliding on the annular projection 8 of the barrel 2. . The resistance, that is, the frictional force caused by the sliding of the projection 12 of the braking member 10 against the annular projection 8 of the barrel 2 reduces the retreat of the refill 4. As a result, the kinetic energy of the refill 4 is reduced, and the impact that the refill 4 finally receives is reduced. Therefore, it is possible to minimize the occurrence of problems such as poor writing due to the impact.

  According to the above-described embodiment of the present invention, when the refill 4 is retracted by a knocking operation, the braking portion that cooperates with the barrel 2 to brake the refill 4, that is, the braking member 10 or the braking member is provided on the outer surface of the refill 4. Since the 30 is provided, the shock applied to the refill 4 can be reduced by a simple mechanism.

  The above-mentioned braking member is formed from a resin material such as polyacetal, for example. Further, since the braking member is separate from the refill 4, the braking member can be applied to an existing refill. However, the braking member may be formed integrally with the refill.

  The braking member or the barrel 2 can adopt any configuration as long as they cooperate with each other. For example, the number of the protrusions 12 or the protrusions 33 of the braking member may be one, three, or five or more. The annular projection 7 or the annular projection 8 provided on the shaft cylinder 2 does not have to be an annular projection or a projection, as long as the annular projection 7 or the annular projection 8 is in contact with the projection of the braking member. For example, the inner diameter of the barrel 2 may be gradually reduced toward the rear, and the inner peripheral surface of the barrel 2 may be brought into contact with the projection of the braking member when the refill 4 is retracted. Further, at this time, the braking member may not have the projection, and the outer surface may simply be brought into contact with the inner peripheral surface having a reduced inner diameter.

  The refill 4 in the above-described embodiment may contain a thermochromic ink containing a thermochromic coloring material. In this case, the knock-type writing instrument is a knock-type thermochromic writing instrument, and the handwriting of the knock-type writing instrument can be thermally discolored by frictional heat generated when rubbed by a friction body as an erasing member.

  Here, the thermochromic ink is a color that maintains a predetermined color (first color) at normal temperature (for example, 25 ° C.) and changes to another color (second color) when heated to a predetermined temperature (for example, 60 ° C.). And then returns to the original color (first color) when cooled to a predetermined temperature (for example, −5 ° C.). In the knock-type writing instrument using the thermochromic ink, the term "erasing" means that the second color is colorless and the drawing line written with the first color (for example, red) is heated to be colorless. I do. Therefore, the writing surface or the like on which the drawing line is written is rubbed by the friction body to generate frictional heat, thereby changing the drawing line to colorless, that is, erasing. The second color may be a color other than colorless.

  As the thermochromic microcapsule pigment to be a thermochromic coloring material, those that change color by heat such as frictional heat, for example, those having a function of changing from colored to colorless, from colored to colored, from colorless to colored, There is no particular limitation, and various types can be used, and examples thereof include a microencapsulated thermochromic composition containing at least a leuco dye, a color developer, and a color changing temperature regulator.

  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, triphenylmethane, spiropyran, fluoran, diphenylmethane, rhodamine lactam, indolyl phthalide, leuco auramine, and the like are conventionally known from the viewpoint of obtaining an ink having excellent coloring properties. They can be used alone (one type) or as a mixture of two or more types (hereinafter, simply referred to as "at least one 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-methylindol-3-yl) phthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1 -Ethyl-2-methylindol-3-yl) -4-azaphthalide, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-dimethylaminofluoran, 3-dibutylamino-6 -Methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-xylidinofluor Orchid, 2- (2-chloroanilino) -6-dibutylaminofluoran, 3,6-dimethoxyfluoran, 3,6-di-n-butoxyfluoran, 1,2-benz-6-diethylaminofluoran, 1 , 2-benz-6-dibutylaminofluoran, 1,2-benz-6-ethylisoamylaminofluoran, 2-methyl-6- (Np-tolyl-N-ethylamino) fluoran, 2- (N -Phenyl-N-methylamino) -6- (Np-tolyl-N-ethylamino) fluoran, 2- (3'-trifluoromethylanilino) -6-diethylaminofluoran, 3-chloro-6 -Cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 3-di (n-butyl) amino-6-methoxy-7-anilinofluoran 3,6-bis (diphenylamino) fluoran, methyl-3 ′, 6′-bisdiphenylaminofluoran, chloro-3 ′, 6′-bisdiphenylaminofluoran, 3-methoxy-4-dodecoxystyrino Quinoline, 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 by opening these skeletons (rings).

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

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

  The amount of the developer used may be arbitrarily selected according to the desired color density, and is not particularly limited. Usually, the amount is 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 discoloration temperature regulator 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, a conventionally known one can be used. Specific examples include alcohols, esters, ketones, ethers, acid amides, azomethines, fatty acids, and hydrocarbons.

More specifically, bis (4-hydroxyphenyl) phenylmethane dicaprylate (C ₇ H ₁₅ ), bis (4-hydroxyphenyl) phenyl methane dilaurate (C ₁₁ H ₂₃ ), bis (4-hydroxyphenyl) phenyl methane di myristate _(C 13 _{H 27),} bis (4-hydroxyphenyl) phenyl ethane di myristate _(C 13 _{H 27),} bis (4-hydroxyphenyl) phenyl methane dipalmitate _(C 15 _{H 30),} bis At least one of (4-hydroxyphenyl) phenylmethane dibehenate (C ₂₁ H ₄₃ ) and bis (4-hydroxyphenyl) phenylethylhexylidene dimyristate (C ₁₃ H ₂₇ ) is exemplified.

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

  The thermochromic microcapsule pigment is obtained by microencapsulating a thermochromic composition containing at least the leuco dye, the color developer, and the color changing temperature regulator such that the average particle size becomes 0.2 to 3 μm. Can be manufactured. Examples of the microencapsulation method include, for example, an interfacial polymerization method, an interfacial polycondensation method, an in situ polymerization method, an in-liquid curing coating method, a phase separation method from an aqueous solution, a phase separation method from an organic solvent, a melt dispersion cooling method, and an air A suspension coating method, a spray drying method, and the like can be given, and can be appropriately selected depending on the use.

  For example, in the phase separation method from an aqueous solution, a leuco dye, a color developer, a discoloration temperature adjuster is heated and melted, then put into an emulsifier solution, heated and stirred to disperse in an oil droplet form, and then as a capsule film agent, Using a resin raw material or the like, for example, an amino resin solution, an isocyanate-based resin solution or the like is gradually added thereto, and subsequently reacted and prepared, and then the dispersion is filtered to produce a desired thermochromic microcapsule pigment. be able to.

  The contents of these leuco dyes, color developers, and color change temperature regulators vary depending on the type of leuco dye, color developer, color change temperature regulator used, microencapsulation method, and the like. The mass ratio is 0.1 to 100 of the color developer and 1 to 100 of the color change temperature regulator. In addition, the capsule membrane agent has a mass ratio of 0.1 to 1 with respect to the capsule contents.

  The thermochromic microcapsule pigment can be appropriately combined with the types and amounts of the above-mentioned leuco dye, developer and discoloring temperature adjusting agent, so that the coloring temperature of each color (for example, coloring at 0 ° C. or higher), the decoloring temperature ( For example, it is possible to set a suitable temperature at 50 ° C. or higher (color erasure), and it is preferable that the color becomes colorless by heat such as frictional heat.

  In the thermochromic microcapsule pigment, it is preferable that the wall film is formed of a urethane resin, a urea / urethane resin, an epoxy resin, or an amino resin from the viewpoints of further improving drawing line density, storage stability, and writability. Examples of the urethane resin include a compound of an isocyanate and a polyol. Examples of the epoxy resin include a compound of an epoxy resin and an amine. Examples of the amino resin include a melamine resin, a urea resin, and a 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 line density.

  The average particle diameter of the thermochromic microcapsule pigment is as follows: coloring, coloring, easy decoloring, stability, fluidity in the ink, and suppressing adverse effects on writing properties; From the viewpoint of compatibility with the microcapsule pigment, the thickness 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) (refractive index 1.8) with a particle size analyzer [Microtrac HRA9320-X100 (manufactured by Nikkiso Co., Ltd.)]. It is.

  If the average particle size is less than 0.2 μm, sufficient drawing line density cannot be obtained. On the other hand, if it exceeds 5 μm, the ink will suffer from poor writing properties, reduced dispersion stability of the thermochromic microcapsule pigment, and vibration. Backing 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 exist at a certain ratio or more, the above-described influence tends to be more remarkable. The microcapsule pigment having the above-mentioned average particle diameter range (0.2 to 5 μm) varies depending on the microencapsulation method. However, in a phase separation method from an aqueous solution or the like, stirring when producing the microcapsule pigment is performed. It can be prepared by suitably combining the 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. In addition, microcapsule pigments having a specific gravity of more than 1.3 easily cause ink back due to vibration.

  In the aqueous ink composition for writing implements, in addition to the thermochromic microcapsule pigments described above, water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.) as a balance, and other writing implements (ballpoint pens) Depending on the intended use, for marking pens, etc.), as long as the effect is not impaired, a water-soluble organic solvent, a thickener, a lubricant, a rust preventive, a preservative or a bactericide, etc. it 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, and ethylene glycol monomethyl ether and diethylene glycol monomethyl. Ethers can be used alone or as a mixture.

  Of these, glycerin is preferably used for the purpose of suppressing ink solidification in the writing portion due to the ink back, and the amount of glycerin is preferably 1 to 10% by mass based on the total amount of the ink. The mechanism of action by glycerin is unknown, but is presumed to have an effect of reducing the cohesive force between the pigment and the ink component 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, gum arabic, tragacanth gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, welan gum, succinoglycan, diutan gum, dextran, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, starch glycolic acid and Its salts, propylene glycol alginate, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl methyl ether, polyacrylic acid and its salts, carboxyvinyl polymer, polyethylene oxide, copolymer of vinyl acetate and polyvinylpyrrolidone, cross-linked acrylic acid polymer and Salts, 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, due to their rheological properties, tend to be less susceptible to fluidity due to vibration, and are less susceptible to problems such as poor writing due to ink back. In particular, xanthan gum is preferable because it has an excellent balance with other characteristics required for the writing instrument ink.

  Examples of the lubricant include fatty acid esters of polyhydric alcohols, higher fatty acid esters of sugar, polyoxyalkylene higher fatty acid esters, alkyl phosphates, alkyl sulfonates of higher fatty acid amides, and alkyl allyl sulfones, which are also used as surface treatment agents for pigments. Examples thereof include acid salts, derivatives of polyalkylene glycol, fluorine-based surfactants, and polyether-modified silicones. Examples of the rust preventive include benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, saponins and the like. Examples of preservatives or antibacterial agents include phenol, sodium omazine, sodium benzoate, and benzimidazole compounds.

  In order to produce the aqueous ink composition for a writing instrument, a conventionally known method can be adopted.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 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 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 in the above range, it is possible to obtain an ink having excellent writability and stability over time. Further, a viscosity equation represented by S = αD ⁿ (where 1>n> 0) (S is a shear stress (dyn / cm ² ), D is a shear rate (s ⁻¹ ), and α is a non-Newtonian viscosity coefficient) The obtained 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 a writing instrument is preferably 25 to 45 mN / m, and 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 the occurrence of ink back can be prevented.

  Within the refill, an ink follower may be located immediately behind the ink. The material constituting the follower can be composed of at least a nonvolatile or non-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. For example, liquid paraffin is used. Mineral oil and chemically synthesized oil are used for 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 examples of polybutene that can be used include commercially available Nissan polybutene 200N, polybutene 30N, polybutene 10N, polybutene 5N, polybutene 3N, polybutene 015N, polybutene 06N, polybutene 0N (all manufactured by NOF Corporation), polybutene HV-15 (produced by Nippon Petrochemical Co., Ltd.) and 35R (produced 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, (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) (Mitsui 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 in the ink follower include a calcium salt of a phosphate ester, fine particle silica, a block copolymer of polystyrene-polyethylene / butylene rubber-polystyrene, a block copolymer of polystyrene-polyethylene / propylene rubber-polystyrene, and hydrogenated styrene. -Butadiene rubber, styrene-ethylenebutylene-olefin crystal block copolymer, olefin crystal-ethylenebutylene-olefin crystal block copolymer, and acetoalkoxyaluminum dialkylate. One or more of these can be used.

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

  Preferred commercial products of the block copolymer of polystyrene-polyethylene / butylene rubber-polystyrene include Kraton GFG-1901X, Kraton GG-1650 (all manufactured by Shell Japan), Septon 8007, and Septon 8004 (all manufactured by Kuraray). Is mentioned. Further, preferred commercial products of the block copolymer of polystyrene-polyethylene / propylene rubber-polystyrene include Kraton GG-1730 (manufactured by Shell Japan), Septon 2006, and Septon 2063 (all manufactured by Kuraray).

  Preferred commercial products of hydrogenated styrene-butadiene rubber include DYNARON1320P, DYNARON1321P (all manufactured by JSR), Tuftec H1041, and Tuftec H1141 (all manufactured by Asahi Kasei Corporation).

  Preferable commercial products of the styrene-ethylene butylene-olefin crystal block copolymer include DYNARON4600P (manufactured by JSR Corporation), and preferable commercial products of the olefin crystal-ethylenebutylene-olefin crystal block copolymer include DYNARON6200P and DYNARON6201B ( JSR).

  Preferred commercial products of acetoalkoxyaluminum dialkylate include Plenact AL-M (manufactured by Ajinomoto Fine Techno Co.).

  Among these thickeners, from the viewpoint of further exhibiting the effects of the present invention, styrene-ethylene butylene-olefin crystal block copolymer, olefin crystal-ethylene butylene-olefin crystal block copolymer and other thermoplastic olefin elastomers Use is preferred.

  In the present invention, in order to obtain an ink follower that prevents the occurrence of ink back, the average value of the tan δ values measured for each frequency while increasing exponentially in the frequency range of 1 to 63 rad / s is 1.0%. It is preferable to set it as above, and it is more preferable to set it to 1.7 to 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 a frequency range of “1 to 63 rad / s”. It is known that those having a value of 1.0 or less are 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 the vibration and prevent the occurrence of ink back.

  Rubber elastic materials such as thermosetting rubbers such as silicone rubber, nitrile rubber, ethylene propylene rubber, and ethylene propylene diene rubber, and thermoplastic elastomers such as styrene-based elastomers, olefin-based elastomers, and polyester-based elastomers, A mixture of two or more types of rubber elastic materials and a mixture of a rubber elastic material and a synthetic resin can be used, and are subjected to a wear test (ASTM D1044) specified in JIS K7204 under a load of 9.8 N and an environment of 1000 rpm. Below, a friction member is formed so that the Taber abrasion amount on the wear wheel CS-17 of the Taber abrasion tester is 10 mg or more. Furthermore, in order to adjust the amount of Taber abrasion to be 10 mg or more, phenyl alkylsulfonate, cyclohexanedicarboxylate, and phthalate plasticizer are added to the friction body material to provide more flexibility. May be. The friction body contains a phenyl alkylsulfonate, a cyclohexanedicarboxylic acid ester, or a phthalic acid-based plasticizer, so that the friction body is more easily worn, so that the paper surface is not damaged and the printed characters are not rubbed. Can be erased. Further, the friction body preferably has a durometer D hardness specified in JIS K6203 of 30 or more. Thereby, a predetermined hardness can be secured, and a more stable rubbing operation can be performed. Note that the friction body can also be applied as a touch pen and a stylus pen.

DESCRIPTION OF SYMBOLS 1 Knock-type writing instrument 2 Shaft barrel 3 Operation part 4 Refill 4a Writing part 5 Spring 10 Braking member

Claims (2)

A shaft cylinder, a writing body disposed in the shaft cylinder, an elastic member for urging the writing body rearward, and an operation of being pressed forward against the urging force of the elastic member during a knocking operation And a knock-type writing instrument comprising:
On the outer surface of the cursive, at the time of retreat of the cursive by a knocking operation, a braking unit that performs braking of the cursive in cooperation with the barrel is provided ,
A knock-type writing instrument , wherein the braking portion has a projection and an abutting portion on the inner peripheral surface of the barrel, the abutting portion being in contact with the projection . A shaft cylinder, a writing body disposed in the shaft cylinder, an elastic member for urging the writing body rearward, and an operation of being pressed forward against the urging force of the elastic member during a knocking operation And a knock-type writing instrument comprising:
On the outer surface of the cursive, at the time of retreat of the cursive by a knocking operation, a braking unit that performs braking of the cursive in cooperation with the barrel is provided ,
The braking portion is a separate tubular member detachable from the writing body, and a plurality of ribs for holding the writing body are formed on an inner peripheral surface of the tubular member. Knock-type writing implement.

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