JPH0221271Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ink storage body for a writing instrument. More specifically, a fiber bundle made of a blend of multiple types of fibers including heat-melting fibers is wrapped in a composite film with a low-melting-point thermoplastic resin layer on the inner surface, and the fibers are partially heat-melted. An ink absorbing body that forms a homogeneous and stable net-like ink holding space with high porosity, and has an appropriate balance of ink absorbing performance and ink supply toward the pen tip, as well as suppressing the movement of fibers due to impact, etc. It provides:

Conventionally, as an ink absorber for this type of writing instrument,
The proposal disclosed in Japanese Patent Publication No. 50-37571 is widely known. The ink storage body according to the same publication coats a sliver made of a mixture of multiple types of fibers with different melting points with a synthetic resin layer whose melting point is the same as that of the fibers or has a slightly higher melting point among the mixed slivers. It is obtained by processing, and even if the productivity is satisfied, the inner wall of the cylinder and the outer periphery of the sliver are not sufficiently fused, and fiber movement due to impact cannot be avoided.
Furthermore, if the synthetic resin film to be extruded is made thinner, it will depend on the diameter variation of the fiber bundle, making it impossible to stabilize the outer diameter dimension, making it necessary to form a thick film, and effectively retaining ink by the fiber bundle. It was reducing space.

The present invention solves the above-mentioned disadvantages of the conventional technology.

The present invention will be explained in detail below with reference to the drawings.

In the present invention, a cylinder is filled with a fiber bundle 2 which is a blend of crimped short fibers of heat-fusible fibers 2-1 and crimped short fibers that do not melt at the melting point of the fibers, and the heat-fusible fibers 2-1 are filled in a cylinder. In the ink storage body in which the fibers are partially thermally fused by melting -1, the cylindrical body is a thermoplastic resin layer 3-1 having a lower melting point than the heat-fusible fibers.
The resin layer 3-
1 is formed on the inside, and the resin layer 3-
It is characterized by a structure in which the inner surface of the cylindrical body and the outer periphery of the fiber bundle 2 are bonded together by melting the fiber bundle 2.

In the above, the heat-melting fibers 2-1 include fibers such as low-melting point polyester, low-melting point polyamide, low-melting point polyolefin, and polyethylene, having a melting point of about 80° C. to 150° C., and low-melting point polyester-polyester,
Examples include conventionally known composite fibers such as sheath-core type, parallel type, and multilayer type, such as low melting point polyethylene-polypropylene and low melting point polyamide-nylon 6.

On the other hand, the fibers to be blended with the thermofusible fibers are fiber bundles that do not melt at the melting point of the thermofusible fibers 2-1, such as general-purpose polyester, polyamide fibers, acetate, polyolefin, vinyl chloride, vinylon, acrylic, etc. Fibers such as rayon and wool.

The applicable fiber form has a single fiber fineness of 0.5~
30d (preferably 3-8d), fiber length 10-150
A crimped ink having a diameter of mm is effective because it satisfies processing suitability and a balance between ink absorption and ink supply properties.

The fiber bundle 2 is a blend of the above-mentioned fibers and bundled in the longitudinal direction, and contains 5 to 45 parts by weight (preferably 15 to 35 parts by weight) of heat-fusible fibers and fibers that do not melt at the melting point of the above-mentioned fibers. is blended at a ratio of 55 to 95 parts by weight (preferably 65 to 85 parts by weight) by partially heat-sealing between the fibers to provide a stable ink storage space with a reticular and elastic high porosity, In addition to satisfying ink absorption and ink supply in the direction of the pen tip, the pen body insertion part is appropriately compressed,
Solve problems caused by non-contact of fibers.

The cylindrical body is for accommodating and protecting the fiber bundle 2 described above, as well as keeping it in a fixed external shape. Melting point thermoplastic resin layer 3-
1 on one side, and encapsulate the resin layer on the inside, and join the end seams (usually by heat fusion, but it is also possible to use an adhesive)
It is formed by Here, thermoplastic resin layer 3-1
is a layer formed of vinylidene chloride, low melting point polyester, low melting point polyamide, ethylene-vinyl acetate, rosin and its derivatives, hydrogenated petroleum resin, etc., and these resins are combined with a base such as polyester, polyamide, cellulose, cellophane, etc. It is provided on one side of a film (which does not melt at the melting point of heat-fusible fibers), and conventionally known composite films of this type are effective.

It is effective for the thickness of the composite film 3 to be 5 to 200 μm (preferably 20 to 70 μm); anything thinner than the above will lack durability and dimensional stability, and if it exceeds 200 μm, encapsulation molding with a small outer diameter will not be possible. In addition to making it difficult, it also reduces the effective occupancy of the fiber bundle and reduces the ink occlusion property. Furthermore, the film becomes rigid and tends to peel off at the heat-sealed portions of the end seams during the heat treatment described below.

In the present invention, the above-described fiber bundle 2 is wrapped with the composite film 8, and in addition to the above-mentioned effect of partially thermally fusing the fibers by heat treatment, the fiber bundle 2
It is required that the outer periphery of the fiber bundle and the inner surface of the cylinder made of the composite film are integrally bonded by melting of the low melting point thermoplastic resin layer 3-1 to completely prevent movement of the fiber bundle.

The above-mentioned effects will be explained. This will be explained in comparison with the ink storage body disclosed in Japanese Patent Publication No. 50-37571 mentioned at the beginning.

The cylinder body of the same publication is blended with a fiber bundle.
This is due to the synthetic resin film having a temperature higher than the melting point of the low melting point fibers, and the binding between the fiber bundle and the inner surface of the cylinder mainly depends on the low melting point fibers which are a part of the fiber bundle. Therefore, the fiber bundle is bonded in discontinuous lines, and movement of the fiber bundle due to impact or the like cannot be suppressed. In contrast, in the present invention, in addition to the thermofusible fibers 2-1 of the fiber bundle 2, the thermoplastic resin layer 3-1 on the inner surface of the cylindrical body is melted together, increasing the fused area and effectively consolidating. It will be worn. Due to the above-mentioned effective binding effect, even if a bulky fiber bundle with a low fiber packing density is inserted, the movement of the fiber bundle is suppressed, which improves the balance between ink absorption performance and ink supply toward the pen tip. A satisfied ink storage body can be obtained.

To supplement the effects of the present invention, the thermoplastic resin layer on the inner surface of the cylinder has a lower melting point than the thermofusible fibers of the fiber bundle, so the built-in fibers are stuck together during the cooling process after heat treatment. After the fiber bundle has a stable external dimension, the adhesion to the cylinder ends, so that an ink storage body with a stable external shape is obtained without being affected by shrinkage strain of the fibers.

An example of manufacturing the ink storage body of the present invention will be described. A continuous fiber bundle in the longitudinal direction, which is a blend of thermofusible fibers and crimped short fibers that do not melt at the melting point of the fibers, in a predetermined ratio is continuously wrapped in a composite film, and at the same time the ends are The seams are joined (usually by heat-sealing) to obtain a continuous covering, and during this process, the material is heated to a temperature above the melting point of the heat-fusible fibers and below the non-deformation or deterioration temperature of the base film, or it is cut into predetermined dimensions. The desired ink storage body can be obtained by heat-treating the beads in the same manner.

Specific examples are described below.

Example 1 Cropped short fibers of polyester fiber (single fiber fineness
3d, fiber length 64mm) and 15 parts by weight of low melting point polyester fiber (melting point 80°C) crimped short fibers (single fiber fineness 6d, fiber length 76mm), 5.0g/ A polyester film with a thickness of 50 μm is prepared by using a sliver of 50 μm and coating one side of the sliver with vinylidene chloride resin,
The coated body was continuously coated with the coating layer on the inside to obtain a coated body having an outer diameter of 6.6 mm, and cut into pieces with appropriate dimensions.

After packing a large number of the pieces into a box, the pieces are heated in a hot air dryer at 120°C for 15 minutes, so that the fibers are partially heat-sealed, and the coating layer is melted to form the inner surface of the cylinder. An ink storage body was obtained in which the outer periphery of the sliver was bound.

Example 2 A polyolefin-based composite fiber in which one half of the outer surface is polyethylene and the other half is polypropylene (single fiber fineness 3d, fiber length 64 mm, number of crimps 10 to 12)
An example was prepared using a 5 g/m sliver blended with 15 parts by weight of polyester fiber (single fiber fineness 3d, fiber length 64 mm, number of crimps 20 threads/inch). After coating with the same composite film as in 1, heat treatment to make the outer diameter 6.0mmφ
An ink absorbing body of 1 was obtained.

The ink storage body of each of the above examples has a high porosity (86
~90%), which absorbs a large amount of ink and has an appropriate capillary balance with the ink guiding wick that directs the ink to the back of the ball such as a pen tip or water-based ballpoint pen, allowing ink to flow smoothly to the writing tip. It has a highly efficient ink consumption rate, and also prevents the movement of fibers due to impact etc., making it suitable for water-based or oil-based felt-tip pens, marking pens, and markers for recorders, printers, plotters, etc. be.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the ink absorber of the present invention;
The figure is a partially enlarged cross-sectional view of FIG. 1. 1... Ink storage body, 2... Fiber bundle, 2-1...
...Thermofusible fiber, 3... Composite film, 3-1...
...Thermoplastic resin layer.

Claims (1)

[Scope of utility model registration request] A cylinder is filled with a fiber bundle that is a blend of crimped short fibers of heat-fusible fibers and crimped short fibers that do not melt at the melting point of the fibers, and the heat-fusible fibers are melted to partially connect the fibers. In the ink absorbing body heat-sealed to the cylindrical body, the cylindrical body is a composite film having a thermoplastic resin layer with a lower melting point than the heat-fusible fiber on one side,
An ink storage body for a writing instrument, which is formed with the resin layer on the inside, and is formed by melting the resin layer to bind the inner surface of the cylinder and the outer periphery of the fiber bundle.