JP2006076016A - Writing implement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writing implement which gives an appropriate fitting force to at least fitting parts of a cap, a tip holder of the writing implement and a holder tube so as to seal the cap, in regard to the writing implement including a felt-tip pen, a marker, a marker for a whiteboard, a ballpoint pen, a brush-tip pen, a white-out pen, an applicator, etc. <P>SOLUTION: This writing implement is constituted by forming silicone curing polymerization films on at least the fitting parts S<SB>1</SB>and S<SB>2</SB>of the cap, the tip holder of the writing implement and the holder tube. The silicone curing polymerization film is preferably formed by applying silicone varnish and then drying it, and a curing mechanism of the silicone varnish is preferably of a condensation type, an addition type or a UV type. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a writing instrument including a sign pen, a marker, a whiteboard marker, a ballpoint pen, a brush pen, a correction liquid pen, a brush pen, an applicator, and the like. It is related with the writing instrument which gave the appropriate fitting force to the fitting part at least.

  Generally, when the sealing performance of the cap is increased, the fitting force between the cap and the writing instrument main body shaft is increased, which often causes a problem that the cap of the pen body cannot be easily removed.

In order to solve this problem, conventionally, a liquid lubricant has been applied to adjust the fitting force between the cap and the writing instrument body shaft. Also known is a writing instrument cap characterized in that a coating layer of an elastic synthetic resin of urethane type, epoxy type, ethylene-vinyl acetate type or butyral type is provided at least on the inner peripheral surface to be fitted to the writing tool shaft body. (For example, refer to Patent Document 1).
However, in the case where the above-described lubricant is applied or the one provided with a coating layer of an elastic synthetic resin, there is a problem that a sufficient fitting force adjustment effect cannot be obtained unless a large amount is applied. There is a problem that may adhere to other than the fitting portion.

In order to solve these problems, the present applicant applied a highly polymerized dimethylpolysiloxane having a viscosity of 300,000 cps to 10 million cps at 20 ° C. to the inner surface of the cap, and the cap and cap of the writing instrument characterized in that (See, for example, Patent Document 2).
This writing instrument cap gives an unprecedented excellent mating force, but this mating force is temporary and the adhesion between the resin effect film and the shaft material is insufficient, so it is mating While repeating the above, problems such as peeling of the cured film occur.
Japanese Utility Model Publication No. 55-83381 (Scope of claims for utility model registration) JP-A-8-300879 (Claims, Examples, etc.)

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art and the current situation, and aims to solve this problem. An object of the present invention is to provide a writing instrument that has a stable fitting force adjustment effect even when repeated fitting is performed. To do.

  As a result of intensive studies to solve the above-described conventional problems, the present inventors have formed a cured film having specific physical properties at least at the fitting portion between the front shaft and the shaft tube of the cap and the writing instrument, It has been found that a writing instrument for the above purpose can be obtained, and the present invention has been completed.

That is, the present invention resides in the following (1) to (7).
(1) A writing instrument, wherein a silicone-cured polymer film is formed at least in a fitting portion between a tip shaft and a shaft tube of a cap and a writing instrument.
(2) The writing instrument according to the above (1), wherein the silicone cured polymer film is formed by applying a silicone varnish and then drying.
(3) The writing instrument according to the above (2), wherein the curing mechanism of the silicone varnish is any one of a condensation type, an addition type, and a UV type.
(4) The writing instrument according to (2) or (3) above, wherein a silicone varnish containing 1 to 10% by weight of silica fine particles is applied.
(5) The silicone-cured polymer film is formed in any one of the above (1) to (4), which is formed after the activation treatment is performed on at least the fitting portion between the front shaft and the shaft tube of the cap and the writing instrument. Writing instrument as described.
(6) The silicone cured polymer film is formed in any one of the above (1) to (4), which is formed after the adhesive layer treatment is performed on at least a fitting portion between the front shaft and the shaft tube of the cap and the writing instrument. Writing instrument as described.
(7) The writing instrument according to any one of (1) to (6), wherein the silicone cured polymer film has a thickness of 0.05 to 200 μm.
The “writing instrument” defined in the present invention includes writing instruments such as a sign pen, a marker, a whiteboard marker, a ballpoint pen, a brush pen, a correction liquid pen, and an applicator such as a liquid applicator and a cosmetic liquid applicator. It is a waste.

  According to the present invention, there is provided a writing instrument having a fitting force adjustment effect that is stable for a long period of time without peeling off the cured silicone film that adjusts the fitting force even when repeated fitting is performed.

Hereinafter, embodiments of the present invention will be described in detail.
The writing instrument of the present invention is characterized in that a silicone-cured polymer film is formed on at least the fitting portion between the cap and the front shaft and the barrel of the writing instrument, and a sign pen, a marker, a marker for whiteboard, In addition to writing instruments such as ballpoint pens, brush pens, correction liquid pens, etc., the present invention can be applied to applicators such as liquid applicators and cosmetic liquid applicators.

1-4 is a writing instrument which shows 1st Embodiment of this invention.
FIG. 1 is a partial longitudinal sectional view showing a writing instrument according to a first embodiment of the present invention, and FIG. 2 is an operation state in which a tip shaft of the writing instrument is fitted to a shaft cylinder, and an operation in which a cap member is fitted to the tip axis. FIG. 3 is an enlarged partial vertical sectional view showing a fitting portion for forming a silicone-cured polymer film on a tip shaft that becomes a fitting portion between the cap and the shaft tube, and FIG. It is a front view which shows the state which removed.
As shown in FIGS. 1 to 3, the writing instrument A according to the first embodiment includes a shaft cylinder 12 including a front shaft 10 and a rear shaft 11 integrally having a tail plug portion, and an ink occlusion body 15 including a fiber bundle. , A relay core 20 made of a fiber bundle, an ink occlusion body 15 and a holding member 25 for holding the relay core 20, an ink guide tube 30, a pen tip 40 made of a fiber bundle, and a cap member 50. The cap member 50 includes an inner cap 51 and an outer cap 52.

The front shaft 10 is made of a synthetic resin or the like having visibility (transparent or translucent), and a small-diameter portion 10a having a tapered portion on the tip side and a large-diameter portion 10b are integrated. There is a structure in which the front portion of the ink guide tube 30 fitted with the pen tip 40 is mounted in the small diameter portion 10 a and the ink guide tube 30 is accommodated in the large diameter portion 10 b through the holding member 25. Yes.
As the front shaft 10, a synthetic resin having visibility (transparent or translucent), for example, a polyolefin resin such as polypropylene (PP), polyethylene (PE), cyclic polyolefin, poly (1-methyl-4-pentene), Polycarbonate (PC), polystyrene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyamide, and thermoplastic resins having visibility such as fluoroplastics such as fluororesin and vinylidene fluoride Can be used.

The outer peripheral surface of the small-diameter portion 10a of the front barrel 10 has a mating surface (mating portion) S ₁ the inner cap 51 of the cap member 50, fitting projections a, b are formed at predetermined intervals Yes. On the other hand, fitting protrusions c and d are also formed at predetermined intervals on the inner peripheral surface of the inner cap 51 of the cap member 50. The fitting projections c and d of the inner cap 51 get over the fitting projections a and b of the front shaft 10 so that the cap member 50 is fitted to the outer peripheral surface of the small-diameter portion 10a of the front shaft 10. is there.
Further, the rear side outer peripheral surface of the large diameter portion 10b of the front barrel 10 has a mating surface (mating portion) S ₂ a shaft 11 after the barrel, the fitting projection e is formed Yes. On the other hand, a fitting projection f is also formed on the inner peripheral surface of the rear shaft 11. The rear shaft 11 is fitted to the front shaft 10 by the fitting projection f of the rear shaft 11 getting over the fitting projection e of the front shaft 10.

In the present invention, as shown in FIG. 3, silicone cured polymer films are respectively applied to the fitting portion S _{1 on} the outer peripheral surface of the small diameter portion 10a of the tip shaft 10 and the fitting portion S ₂ on the outer peripheral surface of the large diameter portion 10b. It is formed.
The silicone cured polymer film formed on the fitting portions S ₁ and S ₂ is not particularly limited as long as it is a cured polymer film made of a silicone resin. For example, a silicone varnish having a dimethyl silicone is used. Can be mentioned. Examples of the curing mechanism of the silicone varnish include a condensation type, an addition type, and a UV type. Furthermore, the silicone varnish contains silica fine particles, and the acrylic resin contains dimethyl. Examples include those obtained by grafting silicone.

In the cured product of the silicone varnish constituting the silicone cured polymer film formed in the fitting portions S ₁ and S ₂ , the addition mold is excellent in that it has no by-product during curing and cures to a deep part. Further, the UV type has a short curing time and does not require heating, and therefore has excellent curing processing performance and handling performance. Further, the above condensation types include dealcohol, deoxime, deacetic, deamine, deamid, deamidoxy, deacetone, dehydrogenate, and dehydration types. There are types that cure with liquid or two liquids. As cured products of these silicone varnishes, a condensation type is preferred from the viewpoint of excellent workability, usability, cost, and strength, more preferably, even among cured products of silicone varnish, the strength is strong and the fitting force is most easily adjusted. A one-part deoxynium type is particularly desirable.

Further, the cured polymer film comprising silica fine particles in the silicone varnish can be made harder and stronger than the cured polymer film made of a cured silicone varnish alone. Silicone has essentially a low intermolecular force and an amorphous structure, so that its hardness and strength are slightly weak and the coating film may be easily broken. As a method for compensating for some of the drawbacks, hardness and strength can be improved by containing silica fine particles and the like. Silanol groups in the silica and the silanol groups after the silicone varnish are hydrolyzed and siloxane bonds by a dehydration condensation reaction and chemically bonded to improve hardness and strength.
Moreover, when using the silicone varnish containing the said silica fine particle, it is desirable to apply | coat after diluting the silicone varnish which a silica fine particle contains 1 to 10% with an organic solvent to 0.01 to 1% density | concentration. It is particularly desirable to use a silica varnish obtained after dilution in which the concentration of silica fine particles is 0.0001 to 0.1%, preferably 0.001 to 0.01%. Further, the silica is preferably amorphous silica.
As a material for forming these cured polymer films, specifically, X-31-608T (deoxynium type: containing 5 wt% of amorphous silica fine particles with respect to 20 wt% of silicone, manufactured by Shin-Etsu Chemical Co., Ltd.), SG-204 (polysiloxane graft polymer, manufactured by Nippon Shokubai Co., Ltd.), JS-025 (polysiloxane graft acrylic resin, manufactured by Nippon Paint Co., Ltd.), Teflon (registered trademark) AF1600 (manufactured by Mitsui DuPont Fluorochemical Co., Ltd.), Cytop TL110A CTL110S (Asahi Glass Co., Ltd.) or the like can be used.

Examples of a method for forming a silicone-cured polymer film on the fitting portions S ₁ and S ₂ include, for example, a silicone varnish (addition type, UV type, condensation type) having the dimethyl silicone or a silica fine particle, the graft Apply resin as it is, or by dissolving it in a solvent such as isohexane, methylcyclohexane, isopropyl alcohol / toluene mixed solvent, normal propyl alcohol, etc. A silicone-cured polymer film can be formed on at least a fitting portion between the cap and the front shaft of the writing instrument and the shaft tube by immersing the portion in each coating resin solution (dipping method) or the like.

In the present invention, in order to further strengthen the fitting portions S ₁ and S ₂ and to adhere the silicone cured polymer film, the silicone cured polymer film is formed after the surface of the fitting part is activated. The silicone cured polymer film may be formed after forming the adhesive layer on the surface, or the adhesive layer may be further formed after the surface activation treatment, and then the silicone cured polymer film may be formed.
Examples of the activation treatment include at least one activation treatment selected from ozone treatment, plasma treatment, corona treatment, ultraviolet irradiation treatment, high-pressure discharge treatment, and acid treatment.
Wood.
As ozone treatment, a member (including a shaft member) including fitting portions S ₁ and S ₂ to which a silicone cured polymer film is applied is placed in a container containing air, oxygen, nitrogen, carbon dioxide, argon, neon, etc., and glow discharge is performed. This is done by exposure to the plasma generated by The surface of the front shaft 10 is placed in a container containing oxygen, nitrogen, carbon dioxide, argon, neon, etc., and is exposed to plasma generated by glow discharge. In order to introduce functional groups such as carboxylic acid groups, carbonyl groups, amino groups, and the like, plasma discharge forms include DC discharge, low frequency discharge, radio wave discharge, microwave discharge, etc. It is not limited.

As the corona treatment, the fitting member surface can be activated by passing a front shaft member (fitting member) having a fitting portion in an electric field where corona discharge occurs.
As the ultraviolet irradiation treatment, the method of irradiating the surface of the fitting member with ultraviolet rays, when the surface of the fitting member is irradiated with ultraviolet rays, the ultraviolet ray is absorbed into a chemical structure such as a double bond in the surface region of the fitting member, The chemical bond is broken by the absorbed energy, and the purpose is to introduce carbonyl group, carboxyl group, etc. obtained by bonding oxygen in the air to the generated radical. A high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like can be used, but is not particularly limited.
The high-pressure discharge treatment is a method in which a high voltage of several hundred thousand volts is applied between electrodes provided with a large number of fitting members, and the discharge is performed in the air. The discharge causes oxygen in the air and the surfaces of the fitting members to be discharged. When activated, oxygen is taken into the surface, and the surface of the fitting member can be activated by introducing a polar group.
The acid treatment can be performed by directly immersing the fitting member table in a chromium mixed acid solution, sodium hypochlorite / hydrochloric acid / water system, chlorate-sulfuric acid system, sulfuric acid, or the like.

  The adhesive layer improves adhesion with the fitting member and improves long-term durability. For example, a coating having a polysiloxane structure and a methyl methacrylate group is applied, or a metal alkoxide is applied by a sol-gel method. It can be formed by applying a solution obtained by hydrolysis and polycondensation and irradiating with ultraviolet rays.

The thickness of the silicone cured polymer film formed on the fitting portions S ₁ and S ₂ is preferably 0.02 to 200 μm, more preferably 0.05 to 50 μm. The formation of this thickness can be adjusted by changing the number of coatings, the concentration of the coating solution, and the like.
When the thickness of the cured polymer film of silicone is less than 0.02 μm, the effect of adjusting the fitting force is weak. On the other hand, when the thickness exceeds 200 μm, the fitting force is weakened.

In the writing instrument A of the embodiment configured as described above, a silicone cured polymer film made of silicone varnish or the like is formed on the fitting portions S ₁ and S ₂ between the cap and the front shaft of the writing instrument. Even if it does, the cured silicone polymer film that adjusts the fitting force does not peel off, and a writing instrument having a fitting effect adjustment effect that is stable for a long period of time can be obtained.
Preferably, in the silicone cured polymer film constituted by containing at least 0.1 to 10% by weight of silica fine particles in the recon varnish forming the silicone cured polymer film, the writing instrument further having a stable fitting force adjustment effect It can be.
Furthermore, after the surface of the fitting part is activated, a silicone cured polymer film is formed, or after forming an adhesive layer on the surface of the fitting part, a silicone cured polymer film is formed, and the surface of the fitting part is activated. In the case where the adhesive layer is further formed and the silicone cured polymer film is subsequently formed, the fitting portions S ₁ and S ₂ can be further strengthened, and the silicone cured polymer film can be closely adhered. Therefore, even if it repeats fitting, it can be set as the writing instrument which has the durability which the silicone cured polymer film does not peel and has the outstanding durability, and also the adjustment effect of the stable fitting force.

In this writing instrument A, as shown in FIGS. 1 to 4, the ink impregnated in the ink occlusion body 15 passes through the ink guide tube 30 through the relay core 20 and permeates the pen tip 40 and can be written. In addition, since the ink end sign from the ink occlusion body 15 can be detected by visually recognizing the ink guide tube 30 through the front shaft 10 serving as a visual recognition portion, the pen tip 40 In this case, it is possible to clearly and easily determine visually whether the ink scum is caused by drying at the nib 40 or due to the ink being consumed.
In addition, the air replacement accompanying the ink consumption is performed by passing through the air hole leading from the pen tip 40 and through the air passage inside the shaft tube to the pad end surface portion. Further, the end surface of the ink occlusion body 15 on the side where the ink guide tube 30 and the ink occlusion body 15 are joined is closed with respect to the outside air, and the O-ring 11 a Since the ink guide tube 30 is closed with respect to the outside air by being inserted through the ink, there is no inflow of outside air (air) into the ink guide tube 30 and the ink is interrupted by an impact such as a drop. It has a structure that does not happen.
Further, in the present embodiment, as shown in FIG. 2, since the tip shaft 10 is removable, the ink occlusion body 15, the relay core 20, the ink guide tube 30, the pen tip 40, and the like serving as the batting are cartridges. Therefore, the structure can be easily replaced and can be used again.

FIG. 4 is a writing instrument B according to the second embodiment, which is an embodiment used for a fitting portion of a direct liquid sign pen having a collector structure.
The sign pen B of this embodiment is formed by filling the ink tank portion 60 serving as a shaft cylinder that directly stores the writing instrument ink composition or the coating liquid X without occluding the padding or the like.
In the figure, X is ink or coating liquid, 61 is a collector member, 62 is a pen tip, 63 is a relay core, 64 is a front shaft, 65 is a rear shaft fixed to the rear portion of the ink tank 60, and 66 is The cap member has an inner cap 66a and an outer cap 66b.

In the writing instrument B of the present embodiment, the cap member 66 to the fitting portion S ₃ of the outer peripheral surface of the front barrel to be fitted, is obtained by forming a cured polymeric films of the aforementioned silicone. Note that S ′ _{3 of the} cap member 66 is a fitting surface that fits with the front portion of the shaft tube 60.
In writing instrument B of this embodiment, the mating portion S ₃ of the cap member 66, so by forming a cured silicone polymer film with a silicone varnish, a silicone curing polymerization to adjust even after repeated mating fitting force The film is not peeled off, and a writing instrument having a long-term stable fitting force adjustment effect can be obtained.
Ink writing from the ink tank 60 to the pen tip 62 in the writing instrument B is performed by using ink or ink from the ink tank 60 via the relay core 63 provided with the ink flow path 61a attached to the central hole of the collector member 61. This is done by leading the coating liquid X to the pen tip 62.
Further, the ink or the coating liquid may be led out by directly arranging the rear portion of the pen tip 62 in the ink tank unit 60 without interposing the relay core 63.

FIG. 6 shows a liquid applicator C according to the third embodiment, which is an embodiment applied to a fitting portion of a liquid applicator having a valve mechanism.
In the liquid applicator C of this embodiment, the ink tank 70 serving as a shaft body that directly stores the coating liquid X without occluding the filling liquid X or the like is filled.
In the figure, 71 is a valve mechanism part, 72 is a pen point, 73 is a front shaft, 74 is interposed between the valve mechanism part 71 and the holder member 73 and holds a rear part of the pen point 72, and 75 is a cap member. Yes, it has an inner cap 75a and an outer cap 75b. Reference numeral 76 denotes a stirring ball.

In the liquid applicator C of the present embodiment, the cap member 75 to the fitting portion S ₄ of the outer circumferential surface of front barrel 73 to be fitted, is obtained by forming a cured polymeric films of the aforementioned silicone. Note that S ′ _{4 of the} cap member 75 is a fitting surface that fits with the front shaft 73.
In the liquid applicator C of this embodiment, the mating portion S ₄ of the cap member 75, to adjust the so obtained by forming a cured silicone polymer film with a silicone varnish or the like, even after repeated mating fitting force silicone The cured polymer film is not peeled off, and a writing instrument having a long-term stable fitting force adjustment effect can be obtained.

Needless to say, the writing instrument of the present invention is not limited to the first to third embodiments, and can be changed to various forms without departing from the gist of the present invention.
Since the gist of the present invention is a structure formed by forming a silicone-cured polymer film on at least the fitting portion between the front shaft and the shaft cylinder of the cap and the writing instrument, the configuration not changing this gist is particularly limited. Instead, various known writing instrument structures can be used, and the pen tip and ink type can be applied to ballpoint pens, sign pens, marking pens, marking pens, white bird markers, writing pens, etc., to provide writing instruments suitable for various uses. It is something that can be done.
Furthermore, the present invention may be applied to applicators that use ink for writing instruments as liquid cosmetics such as correction liquids, coating liquids, and cosmetics.

  EXAMPLES Next, although this invention is demonstrated further in detail based on an Example and a comparative example, this invention is not limited to the following Example.

[Examples 1-3 and Comparative Examples 1-3]
Use the Mitsubishi Pencil Whiteboard Marker (PWB-120, conforming to FIGS. 1 to 4) composed of a front shaft, a rear shaft, an ink holding member, an ink occlusion body, a pen tip, a cap member, an ink composition and the like having the following configuration. It was.
(1) Lead shaft 10 (fitting member)
Made of polypropylene (total light transmittance about 85%), large diameter part length 20mm, total length 36mm
(2) Ink occlusion body 15
Consists of polyethylene terephthalate (PET) batting (porosity 80%), diameter 12mm, length 65mm
(3) Relay core 20
Constructed from PET (porosity 60%), diameter 2.9 mm, length 22.5 mm, length 9.5 mm where rear end portion fits into ink occlusion body 15

(4) Ink guide tube length 36 mm, ink flow path volume about 89 mm ³
(5) Pen tip Consists of acrylic fiber sliver core (porosity 55%), length 15 mm
(6) Cap member Made of polypropylene (non-visibility), total length 32mm, outer cap inner diameter 15mm, inner cap inner diameter 0.9mm

(7) Ink composition [Ink composition (ink composition for whiteboard marker, 100% by weight in total)]
Carbon black M-800 4.9% by weight
Denkabutyral # -3000-4 4.9% by weight
Monoethanolamine salt of carboxylated polyoxyethylene lauryl ether 0.1% by weight
Polybutylene glycol distearate 11.7% by weight
Ethyl alcohol 63.7% by weight
n-propyl alcohol 14.7% by weight
Ink surface tension (25 ° C.) 22 mN / m, ink viscosity coefficient (25 ° C.) 5.5 mPa · s, impregnation amount into ink occlusion body 4 g

Example 1
Plasma treatment is applied to the outer peripheral surface of the front shaft to be a fitting member, and X-31-608-T (Oxium type: containing 5 wt% of amorphous silica particles with respect to 20 wt% of silicone, manufactured by Shin-Etsu Chemical Co., Ltd.) is 0 .05% diluted with xylene was applied by dipping method to volatilize the solvent, and then put into a dryer at 80 ° C. and heat treated for 3 hours to form a silicone cured polymer film on the fitting part S ₁ (Thickness 0.1 μm) was formed.
(Example 2)
In Example 1 described above, Example 2 was prepared using a 0.1% diluted solution.
(Example 3)
In Example 1 described above, Example 3 was prepared using a 0.025% diluted solution.

(Unprocessed product)
What did not process any front axis | shaft used as a fitting member was used.
(Comparative Example 1)
Mekuru the mating portion S ₁ of the front barrel to be fitted member (plus Inc., thickness 20 [mu] m) was used as the coated.
(Comparative Example 2)
Ethylene according to mating portion _{S 1} of the front barrel to be fitted member in Japanese Unexamined Utility Model Publication No. 55-83381 - vinyl acetate [(manufactured by Mitsui Poly Chemical Co.) El Pax 40 5%, 95% toluene, thickness 10μm ] Was used.
(Comparative Example 3)
Fitting member and comprising front barrel mating portion _{S 1} in JP-coated high polymer dimethylpolysiloxane solution at 20 ° C. kinematic viscosity 1000000 cst described in 8-300879 JP Example 1 (thickness 0.5 [mu] m) What was done was used.

Using the above Examples, Comparative Examples, and untreated products, the fitting force, sealing property, and durability test (appearance, fitting force, sealing property) were evaluated by the following methods.
These results are shown in Table 1 below.

[Measuring method of mating force]
Each of the above-mentioned Examples, Comparative Examples, and untreated product front shafts was used to produce whiteboard markers having the above-described configuration. The fitting force was measured by pulling the cap at a speed of 10 cm / min with an imada push gauge (100 N) in a state where the cap was fitted to the pen, and measuring the maximum stress until the cap was pulled out.

[Evaluation method of sealability]
A hole was made in the pen cap, and a hose for flowing compressed air was connected to the hole. The pen body was placed in a water tank, and 0.05 MPas of compressed air was allowed to flow, and the presence or absence of air leakage was evaluated according to the following evaluation criteria.
Evaluation criteria:
○: No bubbles are generated.
Δ: Slight bubbles are observed.
X: Bubbles are generated vigorously.

  After removing the cap 1000 times, a sensory evaluation was made that the cured film was not peeled off visually, and the fitting force was measured and the sealing performance was evaluated in the same manner as described above.

As apparent from the results of Table 1 above, the writing instruments of Examples 1 to 3 that are the scope of the present invention are more effective for adjusting the fitting force than the writing instruments of Comparative Examples 1 to 3 that are outside the scope of the present invention. It was found that the durability was high and the sealing performance was also excellent.
When a comparative example etc. are seen individually, since an untreated product has too strong fitting force, there exists a weak problem in usability. In Comparative Example 1, it was found that by repeatedly removing and attaching the cap, the Mekool was wiped off, the fitting force was increased, and the appearance was also deteriorated. In Comparative Examples 2 and 3, the cured coating film peels off by repeatedly removing the cap, so that it is not possible to continue to maintain a good fitting force, and the sealing properties also deteriorate due to the coating film peeling off. It was.

It is a fragmentary longitudinal cross-section which shows the writing instrument of 1st Embodiment of this invention. It is a fragmentary longitudinal cross-section which shows the operation state which fits the front axis | shaft of the writing instrument used as 1st Embodiment to a shaft cylinder, and the operation state which fits a cap member to a front axis | shaft. In the writing instrument of 1st Embodiment, it is an expanded partial longitudinal cross-sectional view which shows the fitting part which forms a silicone cured polymer film in the front axis | shaft used as a fitting part with a cap and a shaft cylinder. It is a front view which shows the state which removed the cap in the writing instrument of 1st Embodiment. It is a longitudinal cross-sectional view which shows the writing instrument of 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the writing instrument of 3rd Embodiment of this invention.

Explanation of symbols

A Writing instrument S _{1 to} S ₄ Part for forming a silicone cured polymer film 10 Lead shaft 11 Rear shaft 12 Shaft cylinder 15 Ink occlusion body 20 Relay core 30 Ink guide tube 40 Pen tip 50 Cap member

Claims (7)

  A writing instrument, wherein a silicone-cured polymer film is formed at least in a fitting portion between a cap and a tip shaft and a barrel of the writing instrument.   2. The writing instrument according to claim 1, wherein the silicone cured polymer film is formed by drying after applying a silicone varnish.   The writing instrument according to claim 2, wherein the curing mechanism of the silicone varnish is one of a condensation type, an addition type, and a UV type.   The writing instrument according to claim 2 or 3, wherein a silicone varnish containing 1 to 10% by weight of silica fine particles is applied.   The silicone cured polymer film is a writing instrument according to any one of claims 1 to 4, wherein the silicone cured polymer film is formed after an activation process is performed on at least a fitting portion between a cap and a front shaft and a barrel of the writing instrument.   The silicone cured polymer film is a writing instrument according to any one of claims 1 to 4, wherein the silicone cured polymer film is formed after an adhesive layer treatment is applied to at least a fitting portion between a cap and a front shaft and a shaft cylinder of the writing instrument.   The writing instrument according to any one of claims 1 to 6, wherein the silicone-cured polymer film has a thickness of 0.05 to 200 µm.

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