JP7301597B2 - writing instrument - Google Patents

Description

The present invention relates to a writing instrument, particularly a double-ended writing instrument.

A so-called double-headed writing instrument having writing parts at both ends of a barrel is known (for example, Patent Document 1). A double-headed writing instrument described in Patent Document 1 has two caps detachably fitted to either end (Patent Document 1).

Japanese Utility Model Laid-Open No. 2-8995

The cap described in Patent Literature 1 may not be able to obtain a sufficient fitting force due to deformation. That is, the cap described in Patent Document 1 is provided with a fitting portion at the open end, and is fitted with the corresponding fitting portion of the barrel. The open end of the cap is easily deformed due to its shape. As a result, if the double-headed writing instrument described in Patent Document 1 is used for a long period of time, the fitting portion of the cap may not properly fit with the fitting portion of the barrel, and the cap may come off unintentionally. There is In particular, in the case of a writing instrument such as that described in Patent Document 1, in which the writing part of the cursive body is arranged not on the central axis line of the barrel but at a position spaced apart from the central axis line, the opening end of the cap is not circular. Depending on the direction of the applied force, it becomes easier to deform. Further, when the cap is configured to be used as an erasing member, it can be more easily deformed by firmly gripping it during the erasing operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a writing instrument having a cap that can be tightly fitted to a barrel.

According to one aspect of the present invention, the writing device has a barrel, a writing section provided at at least one end of the barrel, and a non-circular open end that covers the writing section and fits into the barrel. and a cap, wherein the writing part is arranged at a position spaced apart from the central axis of the barrel, and a fitting position between the cap and the barrel is spaced apart from the vicinity of the open end of the cap. There is provided a writing instrument characterized by:

The writing portion may be provided at both ends of the barrel, and two caps covering each of the writing portions may be provided. The cap may be axially symmetrical. The cap may be fittable on both ends of the barrel. The writing instrument is a thermochromic writing instrument, and the surface hardness of the cap may be 50 or more and less than 80 durometer D hardness in order to suitably obtain the functions of both the cap and the color changing instrument.

Aspects of the present invention have the common advantage of providing a writing instrument with a cap that can be tightly fitted onto the barrel.

1 is a perspective view of a double-ended writing instrument according to an embodiment of the present invention; FIG. FIG. 2 is a perspective view of the double-ended writing instrument of FIG. 1 with the cap removed. 3 is a longitudinal sectional view of the double-ended writing instrument of FIG. 1. FIG. 4 is another vertical cross-sectional view of the double-ended writing instrument of FIG. 1; FIG. FIG. 5 is a longitudinal sectional view of the barrel. FIG. 6 is a perspective view of the mounting member. FIG. 7 is a vertical cross-sectional view of the mounting member. FIG. 8 is a perspective view of the cap. FIG. 9 is a vertical cross-sectional view of the cap. 10 is an enlarged view of the X section in FIG. 3. FIG. 11 is an enlarged view of a Y portion in FIG. 4. FIG. FIG. 12 is a front view of a double-ended writing instrument set.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Corresponding elements are provided with common reference numerals throughout the drawings.

1 is a perspective view of a double-ended writing instrument 1 according to an embodiment of the present invention, FIG. 2 is a perspective view of the double-ended writing instrument 1 of FIG. 1 with a cap 30 removed, and FIG. 4 is another longitudinal sectional view of the double-ended writing instrument 1 of FIG.

A double-headed writing instrument 1 has two refills 2 which are writing bodies having a writing part 3 at one end, a barrel 10 having a clip 11 on its side, two mounting members 20, and two caps 30. are doing. Within the barrel 10, each of the two refills 2 is arranged in parallel. The double-headed writing instrument 1 attaches the writing part 3, specifically the refill 2, to the barrel 10 by fitting two attachment members 20 to respective ends of the barrel 10. As shown in FIG. You may call the barrel 10 including the fitting member 20 which fitted.

"Axis" or "central axis" means the central axis of the double-headed writing instrument 1 unless otherwise specified. In the axial direction of the double-headed writing instrument 1 or the barrel 10, the end opposite to the side where the clip 11 is provided is referred to as a first end A, and the end on the side where the clip 11 is provided is referred to as a first end. It is called 2-end B. Regarding the refill 2, the writing section 3 side is defined as the "front" side, and the side opposite to the writing section 3 is defined as the "rear" side.

FIG. 5 is a longitudinal sectional view of the barrel 10. As shown in FIG. The barrel 10 is formed in a cylindrical shape. The cross-sectional shape of the barrel 10 is generally elliptical or flat, but may be rectangular. In the transverse direction of the barrel 10 , the side surface on which the clip 11 is provided is called a first side surface 12 , and the side surface opposite to the side on which the clip 11 is provided is called a second side surface 13 . The first side surface 12 and the second side surface 13 are composed of a curved surface or a plurality of flat surfaces extending in the axial direction, and the first side surface 12 and the second side surface 13 are connected by two flat surfaces 14 arranged in parallel. (FIGS. 1-4). A through hole 15 extending in the axial direction is formed in the portion of the first side surface 12 facing the clip 11 .

A first concave portion 16 is formed on the first side surface 12 side and a second concave portion 17 is formed on the second side surface 13 side on the inner surface of the first end portion A near the opening end. A third concave portion 18 is formed on the inner surface of the second end portion B near the opening end on the second side surface 13 side. Engagement projections 19 are formed on the inner surface of each of the flat surfaces 14 so as to face each other at a portion closer to the second end B than the center in the axial direction.

6 is a perspective view of the mounting member 20, and FIG. 7 is a longitudinal sectional view of the mounting member 20. As shown in FIG. The mounting member 20 is a hollow member as a whole, and includes an insertion portion 21 that is inserted and fitted into the interior of the barrel 10 and a holding portion 22 that is exposed to the outside of the barrel 10 when fitted into the barrel 10 . and

In the insertion portion 21 , a wide engagement concave portion 23 is formed at a position corresponding to the engagement projection 19 of the barrel 10 when the mounting member 20 is attached to the barrel 10 , that is, on the outer surface near the opening end of the mounting member 20 . formed. In addition, in the insertion portion 21 , a first protrusion 24 is formed at a position corresponding to the first recess 16 of the shaft tube 10 when the mounting member 20 is attached to the shaft tube 10 , and a second recess 17 of the shaft tube 10 is formed. A second protrusion 25 is formed at a position corresponding to .

The holding portion 22 has a tip portion 26 . The tip portion 26 has a shape similar to that of a general writing instrument that is not a double-headed writing instrument. Therefore, the tip portion 26 has a truncated cone-shaped portion continuing to the cylindrical portion, and has an opening at the top for projecting the writing portion 3 of the refill 2 . An annular protrusion 27 is formed on the outer peripheral surface of the cylindrical portion of the distal end portion 26 .

When the mounting member 20 is mounted on the barrel 10, the tip portion 26 is formed to be biased toward either the first side surface 12 side or the second side surface 13 side, and the corresponding first side surface 12 side or the second side surface 13 side is formed. A slope 28 is formed on the other side of the . A plurality of ribs 29 extending in the axial direction are formed on the inner surface of the holding portion 22 . On the inner surface of the holding portion 22, the rib 29 formed on the tip portion 26 side holds the front end portion of the refill 2 arranged on the tip portion 26 side, and the rib 29 formed on the slope 28 side holds the rear end of the refill 2 placed in the .

8 is a perspective view of the cap 30, and FIG. 9 is a longitudinal sectional view of the cap 30. FIG. The cap 30 is a member that covers the writing portion 3 of the refill 2 to protect it, and has an axially symmetrical shape. Due to the axially symmetrical shape, it can be attached to the barrel 10 even when the cap 30 is rotated 180 degrees in the outer peripheral direction. One end of the cap 30 is open and the other end of the cap 30 is closed except for the vent 31 . The open end of cap 30 is formed in a non-circular shape as a whole. Two notch portions 32 are formed at the open end of the cap 30 corresponding to the flat surface 14 of the barrel 10, and a grip portion 33 consisting of a plurality of grooves is formed on the outer surface of the cap 30 following the cutout portions 32 to prevent slipping. formed. Two separation walls 34 facing each other are formed on the inner surface spaced from the vicinity of the open end of the cap 30 . A plurality of minute projections 35 are formed in substantially the same cross-sectional shape including the separation wall 34 . The ventilation hole 31 preferably has a structure that allows ventilation when the cap 30 is accidentally swallowed by an infant or the like. If the ink contained in the refill 2 is easily volatilized, the ventilation hole 31 may not be provided to prevent the ink from drying.

Next, assembly of the double-headed writing instrument 1 will be described. As shown in FIG. 3, one refill 2 is arranged on the side of the first side surface 12 in the barrel 10, and the writing part 3 protrudes outward from the first end A. As shown in FIG. The other refill 2 is arranged on the second side surface 13 side, and its writing part 3 protrudes outward from the second end B. As shown in FIG. Therefore, in the double-headed writing instrument 1, any refill 2, that is, any writing part 3 is arranged at a position spaced apart from the central axis of the barrel 10 and does not coincide with the central axis. In the barrel 10, the writing portion 3 of the refill 2 arranged on the side of the first side surface 12 is projected outward from the second end portion B, and the writing portion of the refill 2 arranged on the side of the second side surface 13 is projected outward. 3 may project outward from the first end A.

The refill 2 is fixed within the barrel 10 by being held by two mounting members 20 . That is, in FIG. 3, in the refill 2 arranged on the side of the first side surface 12, the front end portion is held by the rib 29 on the side of the tip portion 26 of the mounting member 20 fitted to the first end portion A of the barrel 10, In addition, the rear end portion is held by the rib 29 on the slope 28 side of the mounting member 20 fitted to the second end portion B of the barrel 10 . On the other hand, in the refill 2 arranged on the side of the second side surface 13, the front end is held by the rib 29 on the side of the tip 26 of the mounting member 20 fitted to the second end B of the barrel 10, and the rear end is held by the rib 29 on the side of the slope 28 of the mounting member 20 fitted to the first end A of the barrel 10 .

The cap 30 fits over the distal end portion 26 of the mounting member 20 . Specifically, the mounting member 20 and the cap 30 are fitted together by the minute protrusions 35 of the cap 30 getting over the annular protrusions 27 of the distal end portion 26 and engaging with each other. The minute protrusions 35 of the cap 30 are formed inside the cap 30 at a distance from the vicinity of the open end of the cap 30 . In other words, the fitting position between the cap 30 and the mounting member 20 , that is, the barrel 10 is separated from the vicinity of the open end of the cap 30 . Therefore, even if the opening end of the cap 30 is deformed, the portion of the cap 30 where the minute protrusions 35 are arranged inside the opening end is not deformed. Therefore, the deformation of the open end of the cap 30 does not affect the fitting between the tip portion 26 of the mounting member 20 and the cap 30, and the cap 30 can be firmly fitted to the barrel 10. .

The fitting position is separated from the vicinity of the opening end of the cap 30 means that the fitting position is separated from the opening end or the vicinity of the opening end to such an extent that the vicinity of the fitting position of the cap 30 is not deformed. It means being in the vicinity of the writing section 3 or near the writing section 3 . Therefore, as long as the fitting position is spaced apart from the vicinity of the open end of the cap 30, the configuration and arrangement of the protrusions can be arbitrarily adopted.

The cap 30 can be fitted to both ends of the barrel 10, that is, to each of the mounting members 20 fitted to both ends. When the cap 30 is engaged with the mounting member 20 , the refill 2 and corresponding tip 26 are positioned within the cap 30 to one side separated by the separation wall 34 . The interior space defined between cap 30 and mounting member 20 is preferably less than 1200 mm ² .

10 is an enlarged view of the X section in FIG. 3, that is, the first end A. FIG. As shown in FIG. 10, the first recess 16 of the barrel 10 has a recess 16a formed near the open end and an engaging projection 16b formed inside the barrel 10 from the recess 16a. ing. The second recess 17 of the barrel 10 has a recess 17a formed in the vicinity of the open end, and an engagement projection 17b formed inside the barrel 10 from the recess 17a. The recessed portion 16a of the first recessed portion 16 is formed to have a shorter axial length than the recessed portion 17a of the second recessed portion 17 . A recess 18a similar to that of the first recess 16 is also formed in the vicinity of the opening end of the third recess 18 (FIG. 5).

The first projection 24 of the mounting member 20 has a projection 24a formed complementarily to the recess 16a of the first recess 16, and an engaging projection 24b formed closer to the opening end than the projection 24a. . The second protrusion 25 of the mounting member 20 has a protrusion 25a formed complementarily to the recess 17a of the second recess 17, and an engaging protrusion 25b formed closer to the opening end than the protrusion 25a. .

As shown in FIG. 10 , when the mounting member 20 is attached to the barrel 10 , the engaging projection 16 b of the barrel 10 and the engaging projection 24 b of the mounting member 20 are aligned on the first side surface 12 side of the barrel 10 . In addition, the engagement protrusion 17b of the barrel 10 and the engagement protrusion 25b of the mounting member 20 are engaged with each other on the side of the second side surface 13 of the barrel 10 . Thereby, the mounting member 20 fitted to the first end A is configured so as not to be easily removed from the barrel 10 . The engaging projection 24b and the engaging projection 25b of the mounting member 20 constitute a first engaging portion that engages with the barrel 10. As shown in FIG.

When the mounting member 20 is rotated 180 degrees around the central axis, for example, when the tip 26 of the mounting member 20 at the first end A is arranged on the second side surface 13 side, the mounting member 20 is rotated about the central axis. It cannot be fitted to the cylinder 10. That is, as shown in FIG. 10, the recessed portion 16a of the first recessed portion 16 is formed to have a shorter axial length than the recessed portion 17a of the second recessed portion 17. As shown in FIG. Therefore, even if an attempt is made to insert the mounting member 20 into the barrel 10 in this state, the projection 25a of the second projection 25 abuts against the wall surface of the recess 16a of the first recess 16, preventing the insertion of the mounting member 20. be blocked.

Similarly, when fitting the mounting member 20 to the second end portion B of the barrel 10, if the first convex portion 24 of the mounting member 20 is arranged on the side of the third concave portion 18 of the barrel 10, Although it can be fitted, it cannot be fitted when the second convex portion 25 of the mounting member 20 is arranged on the third concave portion 18 side of the shaft tube 10 . Therefore, the mounting member 20 is formed so as to fit into the barrel 10 only at predetermined positions around the center axis of the barrel 10 . As a result, it is possible to prevent the mounting member 20 from being fitted into the barrel 10 in the wrong direction, and to fit the mounting member 20 in the intended direction.

11 is an enlarged view of a Y portion in FIG. 4. FIG. As described above, on the inner surface of each of the flat surfaces 14, the engaging projections 19 are formed to face each other at the portion closer to the second end B than the center in the axial direction. Therefore, as shown in FIG. 11 , the mounting member 20 inserted into the second end portion B engages the engaging recess 23 with the engaging projection 19 of the barrel 10 . Thereby, the mounting member 20 fitted to the second end portion B is configured so as not to be easily removed from the barrel 10 . The engaging recess 23 of the mounting member 20 constitutes a second engaging portion that engages with the barrel 10 . Since the mounting member 20 inserted into the first end A does not have the engagement protrusion 19 formed on the inner surface of the corresponding shaft tube 10, the engagement recess 23 and the shaft tube 10 are not engaged. do not have.

As described above, the mounting member 20 has the first engaging portion and the second engaging portion, one side of the mounting member 20 is engaged with the barrel tube 10 by the first engaging portion, and the other side of the mounting member 20 is It is engaged with the barrel 10 by the second engaging portion. Therefore, even if each mounting member 20 has a dimensional variation at the time of manufacturing, since the engagement positions with the shaft tube 10 are different from each other, it is possible to minimize the influence thereof. As a result, there is an effect that there is no rattling between the mounting member 20 and the barrel 10 . Moreover, as long as such an effect is exhibited, in the two mounting members 20 having the same shape, the configuration and arrangement of the first engaging portion and the second engaging portion can be arbitrarily adopted. In the above-described embodiment, the first engaging portion and the second engaging portion are spaced apart in the axial direction.

As shown in FIG. 1 , a portion of the mounting member 20 is exposed through the notch 32 of the cap 30 when the cap 30 is fitted onto the barrel 10 . Therefore, by making the mounting member 20 the same color as the ink contained in the refill 2 held by the mounting member 20, even when the cap 30 is fitted to the barrel 10, the cap 30 can It becomes possible to know the ink color of the writing part 3 covered. As shown in FIG. 3, in the double-ended writing instrument 1, two refills 2 are arranged in a barrel 10 side by side over most of the axial direction. Therefore, the double-headed writing instrument 1 can be configured with substantially the same overall length while using the same refill as a normal writing instrument that accommodates one refill in the barrel.

By arranging the two refills 2 side by side, it is possible to form a flat surface 14 on the outer surface of the barrel 10 having a larger area than the barrel of a normal writing instrument. As a result, various designs can be applied to the flat surface 14 . Flat surface 14 may be personalized, for example, for gift giving. Also, for the purpose of advertising and the like, a company name, company logo, etc. may be applied. In addition, as shown in FIGS. 1 and 2 , the outer surface of the mounting member 20 is exposed through the through hole 15 of the barrel 10 . The exposed outer surface of the mounting member 20 may be further designed. Furthermore, by forming a plurality of sets of the double-headed writing instrument 1, a series of integral designs may be applied.

FIG. 12 is a front view of the double-ended writing instrument set 100. FIG. In a double-ended writing instrument set 100, a design 101 is applied to each barrel 10 of a plurality of double-ended writing instruments 1, more specifically, to a flat surface 14, so that when adjacently arranged in the same orientation, a series of designs 101 are formed. Here, the design means characters, symbols, pictures, shapes (including three-dimensional shapes), patterns, colors, combinations thereof, or the like. The double-ended writing instrument set 100 is composed of three double-ended writing instruments 1 , but may be composed of two or four or more double-ended writing instruments 1 . As an example of design 101, FIG. 12 shows the letter "NA".

Each of the plurality of double-ended writing instruments 1 of the double-ended writing instrument set 100 may be provided with a different design to be completed by itself. For example, in a double-ended writing instrument set 100 having two double-ended writing instruments 1, a picture of a boy is placed in the barrel 10 of one of the writing instruments 1, and a picture of a girl is placed in the barrel 10 of the other double-ended writing instrument 1. , and arranging them side by side, the design may be such that boys and girls are side by side. Alternatively, one alphabetic character may be placed on each of a plurality of double-headed writing instruments 1, and by arranging these adjacently, one's own name may be formed.

The design 101 is applied, for example, by film transfer. By forming an image on the transfer film by an inkjet method that does not have a solid white layer, the double-ended writing instrument set 100 with excellent decorativeness and a high novelty effect can be obtained. The design 101 may be applied by painting, engraving, or the like.

The double-ended writing instrument set 100 may be housed in a writing instrument case in order to more neatly arrange the writing instrument set 100 and display it in the shop. The writing instrument case may be a box-shaped case with at least a transparent front surface so that the integrated design 101 can be visually recognized. The writing instrument case may have a rectangular bag-like shape such as an envelope instead of a box-like shape, as long as the design 101 is visible by making a part of the case transparent.

Materials used for writing instrument cases include PP, PE, PET, PEN, nylon (including amorphous nylon, etc., in addition to general nylon such as 6 nylon, 12 nylon, etc.), acrylic, polymethylpentene, polystyrene, ABS, etc. It is made of a resin material or a glass material, and is preferably made of a material having a visible light transmittance of 50% or more, more preferably 80% or more. Visible light transmittance can be obtained by measuring reflectance using a multi-light source colorimeter. Furthermore, by including a benzotriazole-based compound, a benzophenone-based compound, a salicylate-based compound, or the like as an ultraviolet absorber, it is possible to prevent discoloration and fading of the printed design 101 .

According to the double-headed writing instrument set 100, when a plurality of double-headed writing instruments 1 are arranged adjacently, the design has a sense of unity, and the effect of motivating the user to purchase a set of a plurality of double-headed writing instruments 1 is exhibited. .

The refill 2 may be a refill for a ballpoint pen, a marking pen, a touch pen, an eraser, or other types of refill such as a friction body. The two refills 2 may be combined with different colors, different handwriting widths (ball diameters), and the like. Also, the cap 30 may be used as an erasing member for erasing handwriting by the double-headed writing instrument 1 .

At least one of the refills 2 may be a refill containing thermochromic ink containing a thermochromic coloring material. In this case, the double-headed writing instrument 1 is a thermochromic writing instrument, and the cap 30 may be a friction body as an erasing member. Handwriting by the double-headed writing instrument 1 can be thermally discolored by frictional heat or the like generated when rubbed by the cap 30 .

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

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

The leuco dye that can be used is not particularly limited as long as it is an electron-donating dye and functions as a color former. Specifically, from the viewpoint of obtaining an ink with excellent color development properties, conventionally known compounds such as triphenylmethane, spiropyran, fluorane, diphenylmethane, rhodamine lactam, indolylphthalide, and leuco auramine It can be used singly (one kind) or in combination 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-xyridinofluorane, 2-(2-chloroanilino)-6- dibutylaminofluorane, 3,6-dimethoxyfluorane, 3,6-di-n-butoxyfluorane, 1,2-benz-6-diethylaminofluorane, 1,2-benz-6-dibutylaminofluorane, 1,2-benz-6-ethylisoamylaminofluorane, 2-methyl-6-(Np-tolyl-N-ethylamino)fluorane, 2-(N-phenyl-N--methylamino)-6- (Np-tolyl-N-ethylamino)fluorane, 2-(3′-trifluoromethylanilino)-6-diethylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 2-methyl-6- Cyclohexylaminofluorane, 3-di(n-butyl)amino-6-methoxy-7-anilinofluorane, 3,6-bis(diphenylamino)fluorane, methyl-3',6'-bisdiphenylaminofluorane , chloro-3′,6′-bisdiphenylaminofluorane, 3-methoxy-4-dodecoxystyrinoquinoline, and the like.

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

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

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

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

The discoloration temperature control agent that can be used is a substance that controls the discoloration temperature in the coloration of the leuco dye and developer. Conventionally known discoloration temperature regulators 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 At least one of (4-hydroxyphenyl)phenylmethane dibehenate (C ₂₁ H ₄₃ ), bis(4-hydroxyphenyl)phenylethylhexylidene dimyristate (C ₁₃ H ₂₇ ) and the like can be mentioned.

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

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

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

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

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

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

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

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

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

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

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

Among these, 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 relative to the total amount of ink. Although the mechanism of action of glycerin is unknown, it is presumed that it has the effect of reducing the cohesive force between pigments and ink components in a dry state.

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

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

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

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

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

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

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

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

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

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

Specific ethylene α-olefin oligomers that can be used include, for example, Lucant HC-10, HC-20, HC-100, HC-150, HC-600, HC-2000 (manufactured by Mitsui Chemicals, Inc.). is mentioned.

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

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

Crodax DP-301LA (manufactured by Croda Japan Co., Ltd.) and the like can be mentioned as a preferable material for the calcium salt of phosphoric acid ester that can be used. Fine particle silica that can be used includes hydrophilic fine particle silica and hydrophobic fine particle silica, and preferred commercial products of hydrophilic silica include AEROSIL-300 and AEROSIL-380 (manufactured by Nippon Aerosil Co., Ltd.). Preferred materials for hydrophobic silica include AEROSIL-974D and AEROSIL-972 (manufactured by Nippon Aerosil Co., Ltd.).

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

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

Preferred materials for the block copolymer of styrene-ethylene butylene-olefin crystal include DYNARON4600P (manufactured by JSR Corporation). made) and the like.

Plenact AL-M (manufactured by Ajinomoto Fine-Techno Co., Inc.) and the like are preferred materials for acetoalkoxyaluminum dialkylate.

Among these thickeners, thermoplastic olefin-based elastomers such as block copolymers of styrene-ethylenebutylene-olefin crystals and block copolymers of olefin crystals-ethylenebutylene-olefin crystals are preferred from the viewpoint of further exerting the effects of the present invention. Use is preferred.

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

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

Synthetic resins such as polyacetal and polypropylene, and mixtures of rubber elastic materials and the above synthetic resins can be used as the material for forming the friction body that discolors the thermochromic ink. (ASTM D1044) under a load of 9.8 N and 1000 rpm, the friction body is formed so that the amount of Taber abrasion on an abrasion wheel CS-17 of a Taber abrasion tester is less than 25 mg.

The surface of the friction body preferably has a durometer D hardness of 50 or more and less than 80 as defined in JIS K 7215-1986. As a result, hardness suitable for the function of the cap to protect the writing part by fitting into the barrel and the function of the friction body to discolor the handwriting can be ensured, and a more stable rubbing operation is possible. In addition, the friction body can be applied as a touch pen or a stylus pen, and may be provided with conductivity.

Also, the friction body is preferably colored with a color having a lower lightness value than the color of the thermochromic ink contained in the refill. That is, when the thermochromic ink is transferred to the surface of the friction body without being discolored when the friction body is used, the transfer of the thermochromic ink can be made inconspicuous. In particular, by making the color of the friction body black or having a brightness value of 2.5 or less, dirt on the surface caused by use of the friction body can be made inconspicuous.

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

At least one of the refills 2 in the above-described embodiment may be a refill containing pencil lead or eraser-erasable ink, and the remaining refills 2 may be refills containing thermochromic ink. In this case, by using a plastic eraser or an eraser as the cap 30, it is possible to erase handwriting with a mechanical pencil lead, pencil lead, or eraser erasable ink. In addition, a plastic eraser or an eraser can be used to rub the handwriting of the thermochromic ink, and the handwriting can be thermally discolored by generating frictional heat.

Therefore, the plastic eraser or eraser can be used as an erasing member for different types of writing, i.e. an erasing member for erasing pencil lead or eraser-erasable ink, and a thermochromic ink for thermochromic ink. It can be used as a friction body that causes (erases). It should be noted that the term “erasable handwriting with a plastic eraser or eraser” as used herein means that the handwriting can be erased by rubbing the handwriting with a plastic eraser or eraser without staining the paper surface, etc. around the handwriting. Say things.

Pencil lead, for example, dispersed or included at least one fine particles selected from inorganic pigments, organic pigments, and dyes (excluding glass powder) as a compounding composition before firing, and has an average thickness of 0.1 to 0.1. Flaky glass powder having an aspect ratio of 2 μm, an aspect ratio of 5 to 150, and a flatness of 200 nm or less, or a granular glass powder having an average particle diameter of 0.1 to 50 μm and a sphericity of 0.1 to 50 μm. is preferably contained in an amount of 3 to 80% by weight based on the total weight of the pencil lead.

The eraser erasable ink has an average particle size of 2 to 20 μm, a non-thermoplastic colored resin particle in an amount of 5 to 30% by weight based on the total amount of the ink composition, and a glass transition point of less than 0°C. It preferably contains at least non-colored particles. The "average particle size" defined here is the average particle size (50% diameter) measured with a particle size analyzer [Microtrac HRA9320-X100 (manufactured by Nikkiso Co., Ltd.)] as described above (refractive index 1 .8).

In this case, the friction body is composed of a shell having a relatively high glass transition temperature (Tg) and a core having a glass transition temperature (Tg) relatively lower than that of the shell, in addition to the friction body described above. It contains an acrylic thermoplastic resin powder, a plasticizer and an inorganic powder having a diameter of 20 to 80 μm, and a thermoplastic resin, the thermoplastic resin being a polyvinyl chloride resin or a copolymer thereof, and the inorganic powder being calcium carbonate and /or Magnesium carbonate is preferred because both the thermochromic ink and the erasable ink can be rubbed together. The term "glass transition temperature (Tg)" refers to the boundary temperature at which the amorphous portion of the acrylic resin powder becomes more mobile and becomes rubbery.

At least one of the refills 2 in the above-described embodiment may be a refill containing non-thermochromic ink, and the remaining refills 2 may be refills containing thermochromic ink. In this case, the cap 30 corresponding to the refill containing the non-thermochromic ink may be made of a material such as hard plastic that has a higher flexural modulus than the friction body. As a result, it is possible to recognize whether the ink contained in the corresponding refill is non-thermochromic ink or thermochromic ink by the tactile sensation when the cap 30 is attached or detached. Furthermore, by making the non-thermochromic ink achromatic and the thermochromic ink chromatic, the writing instrument can be made suitable for learning. Achromatic colors are colors that have only lightness without color, such as white, gray (gray), and black. Chromatic colors are colors that have lightness, such as red, green, and blue. A color that has color, hue, and saturation.

1 Double Headed Writing Instrument 2 Refill 3 Writing Part 10 Axle 16 First Recess 17 Second Recess 19 Engagement Protrusion 20 Mounting Member 23 Engagement Recess 24 First Protrusion 25 Second Protrusion 30 Cap 35 Microprotrusion

Claims (1)

a barrel, a writing section provided at at least one end of the barrel, and a cap covering the writing section and having a non-circular open end fitted to the barrel,
The writing unit is arranged at a position spaced apart from the central axis of the barrel,
a fitting position between the cap and the barrel is spaced apart from the vicinity of the open end of the cap ,
A writing instrument , wherein the cap has an axially symmetrical shape .

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