JP3687986B2 - Method for producing ink occlusion body for writing instrument - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method for producing an ink occlusion body used in a writing instrument such as a marking pen and a whiteboard marker.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 52-46940 shows the core of a writing instrument. The core includes a crystalline polypropylene component having a fiber cross-sectional circumference of 15 to 40% and a melting point of the crystalline polypropylene component. 1 to 30 denier parallel composite fiber converging bodies each comprising a polyolefin polymer component having a fiber cross-sectional circumference of 85 to 60% lower than that of 20 degrees Celsius, The surface portion is self-bonded or point-bonded by thermal fusion of the polyolefin polymer component. With the core having such a configuration, it is possible to obtain an appropriate air circulation property, to prevent ink evaporation, and to improve ink retention.
[0003]
In addition, the ink occlusion body for a writing instrument disclosed in Japanese Utility Model Publication No. 59-126585 is a crimped composite fiber comprising two types of polymers having different melting points and at least a part of the outer surface of which is a low melting point polymer. The cylindrical body is filled with a fiber bundle obtained by blending 5 to 30 parts by weight of the short filaments and 70 to 95 parts by weight of the crimped short fibers of the non-composite fibers that do not melt at the melting point of the low-melting polymer. The low melting point polymer is melted and the fibers are partially heat-sealed. With the ink occlusion body having such a configuration, ink is effectively supplied to the pen body, and poor contact with the pen body can be prevented.
[0004]
[Problems to be solved by the invention]
However, according to the core of the writing instrument disclosed in the above-mentioned JP-A-52-46940, the same quality of the outer sheath is obtained with the homogeneous fibers, that is, the homogeneous crystalline polypropylene component and the polyolefin polymer component. Therefore, there is a problem that the pigment ink absorbed in the core is settled, and the ink occlusion capacity is not sufficient.
[0005]
On the other hand, in the ink occlusion body for writing instruments disclosed in Japanese Utility Model Publication No. 59-126585, as two types of polymers having different melting points, a normal fiber and a composite fiber in which a low melting point polyester is arranged on the outside thereof However, in a blended cotton usually made of a blend with a polyester, the solubility index (SP) is naturally the same material, so that it does not show a significant difference, and therefore a sufficient effect of preventing precipitation of the pigment cannot be obtained.
[0006]
Accordingly, an object of the present invention is to provide a method for producing an ink occlusion body for a writing instrument, which has sufficient ink occlusion capability and can sufficiently prevent sedimentation of the adsorbed pigment ink.
[0009]
[Means for Solving the Problems]
The method for producing an ink occlusion body for a writing instrument according to the present invention comprises a step of blending 20 to 40 parts by weight of a heat-fusible composite staple fiber in which polyethylene is coated on a polyester core and 60 to 80 parts by weight of a polyester staple fiber; The mixed fiber bundle is passed through a hot air chamber to cause a fusing phenomenon between the fibers in the fiber bundle, and a fixed intersection of many fibers is provided in the fiber bundle, and the porosity is 80 to 92%. And a step of forming a cylindrical fiber bundle by heat-sealing a polypropylene resin to the outer periphery of the fiber bundle by extrusion molding . It is desirable to include a step of impregnating the fiber bundle formed into a cylindrical shape with a pigment as a pigment. Furthermore, it is desirable to crimp the heat-fusible composite staple fiber and the polyester staple fiber before blending.
[0010]
[Action]
According to the polyester short fiber for a writing instrument of the present invention, with the above-described configuration, the ink occlusion ability is sufficient, the adsorbed pigment ink can be sufficiently prevented from settling, and the ink can be prevented from falling off. The manufacturing method of the ink occlusion body for writing instruments can be obtained.
[0011]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a cross section of the fiber, and FIG. 2 is a longitudinal cross-sectional view of a cylindrical fiber bundle, that is, an ink occlusion body. As shown in FIG. 1, the heat-fusible composite short fiber 1 is obtained by coating polyethylene 3 on the outer periphery of a polyester core material 2 so as to cover the entire periphery. Thereby, the heat-fusible composite short fiber 1 becomes a modified polyester having a relatively low melting point. The weight ratio of the outer polyethylene 3 is usually about 7 to 50%.
[0012]
As an example, the polyester short fiber 4 uses 70 parts by weight of 3 denier and bias 85, while the heat-fusible composite short fiber 1 uses 30 parts by weight of 2 denier and bias 51. used. These fibers 1 and 4 are loosened using a card machine (not shown) and crimped by a known method.
Next, the heat-fusible composite short fiber 1 and the polyester short fiber 4 are blended so as to have the above weight ratio (30:70), respectively, and this batting or fiber bundle is put in a hot air chamber (not shown). Pass through. Thereby, the heat-fusible composite short fiber 1 and the polyester short fiber 4 are self-bonded at a large number of contact points between the same fibers, and are similarly bonded at a large number of contact points between different fibers. .
[0013]
Furthermore, the fiber bundle obtained in this way is applied to an extruder (not shown), and the polypropylene fiber 5 is placed on the outer periphery of the fiber bundle so that the porosity of the fiber bundle is 80 to 90%, for example 85%. The ink occlusion body as shown in FIG. 2 is obtained. The diameter of the ink occlusion body is about 10 mm, and the thickness of the outer polypropylene fiber 5 layer is about 0.3 mm. The weight of the ink occlusion body is about 16 g / m.
[0014]
As another example, instead of subjecting the fiber bundle to an extruder, the fiber bundle is wound up with a suitable film (not shown) so that the porosity of the fiber bundle is 80-90%, for example 85%. It is also possible to adjust.
The ink occlusion body is impregnated with ink containing a pigment as a pigment. The porosity of the fiber bundle is 85%, and the ratio of the ink when impregnated with the ink is about 65% at the maximum, indicating that the ink occlusion ability is very high. In addition, it was found that even when the writing instrument impregnated with ink was oriented vertically for a long time, the ink did not settle inside the ink occlusion body, and the ink adsorbing / holding ability was excellent.
[0015]
As described above, in the present invention, since the outer periphery of the batting or fiber bundle is heat-sealed by the polypropylene fiber 5 or wound up by an appropriate film, the adhesion between the outer jacket and the batting is good, and the dropout is not caused. In addition to being prevented, the fibers themselves inside the batting are conveniently bonded to prevent sedimentation of the pigment ink. For example, in a batting using a conventional ordinary polyester alone, when the writing instrument is kept vertically for a long time, sedimentation of the pigment is promoted by gravity acting on the axial direction of the ink occlusion body, Therefore, in general, a form that does not allow the writing instrument itself to stand upright is employed to barely prevent quality deterioration. In contrast, the present invention has a high ink adsorbing / holding ability, and prevents the pigment ink from sinking even when gravity acts in the axial direction of the ink occlusion body when the writing instrument is kept vertically for a long time. The This is because the balance between the surface solubility index (SP) of polyethylene 3 coated on the outer periphery of the polyester core material 2 of the heat-fusible composite short fiber 1 and the solubility index of the polyester 4 itself is good. It is thought to be due to. Furthermore, although this ink occlusion body is used by being connected to a pen body (not shown), the ink is smoothly supplied to the pen body.
[0016]
【The invention's effect】
As described above, according to the present invention, the ink occlusion ability is sufficient, the adsorbed pigment ink can be sufficiently prevented from settling, and the ink is smoothly supplied to the pen body. An ink occlusion body for a writing instrument with very good characteristics can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a heat-fusible composite short fiber and a polyester fiber.
FIG. 2 is a longitudinal sectional view of a cylindrical fiber bundle, that is, an ink occlusion body.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Heat-fusion composite short fiber 2 ... Polyester core material 3 ... Polyethylene 4 ... Polyester 5 ... Polypropylene resin

Claims (3)

Blending 20 to 40 parts by weight of heat-fusible composite short fiber (1) coated with polyethylene (3) on polyester core (2) and 60 to 80 parts by weight of polyester short fiber (4); The mixed fiber bundle is passed through a hot air chamber to cause a fusing phenomenon between the fibers in the fiber bundle, and a fixed intersection of a large number of fibers is provided in the fiber bundle, and the porosity is 80 to 92%. And a step of heat-sealing the polypropylene resin (5) to the outer periphery of the fiber bundle to form a cylindrical fiber bundle by extrusion molding. Manufacturing method. The method for producing an ink occlusion body according to claim 1 , comprising a step of impregnating the fiber bundle formed into a cylindrical shape with a pigment as a pigment. The method for producing an ink occlusion body according to claim 1 , wherein the heat-fusible composite short fibers (1) and the polyester short fibers (4) are crimped before blending.

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