JP3016749B2 - Anti-reflux agent for water-based ballpoint pen ink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backflow inhibitor for aqueous ballpoint pen ink.

[0002]

2. Description of the Related Art Since the ink of a water-based ballpoint pen is water-based and has low viscosity, a backflow inhibitor is provided at the end of the water-based ink filled in the ink storage tube of the ballpoint pen. As the backflow preventive, those having a composition in which a gelling agent or a polyolefin-based thermoplastic elastomer is blended with an oily substance have been used (as a similar technique, see Japanese Patent Application Laid-Open No. Hei 9-2).
4689).

[0003]

However, such conventional anti-reflux agents cannot satisfy all of the properties required for anti-reflux agents. That is,
The anti-reflux agent is required to have five performances: good impact resistance, no oil separation, good follow-up properties, no blurring of the ink, and no dripping or cross-flow phenomenon. However, even if the amounts of the gelling agent and the polyolefin-based thermoplastic elastomer are adjusted, all the performances cannot be satisfied.

The present invention has been made by paying attention to such a conventional technique, and an object of the present invention is to provide an aqueous ballpoint pen ink backflow inhibitor capable of satisfying all necessary performances.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present inventor has intensively researched a backflow preventing agent capable of satisfying all the performances. Successful.

That is, the anti-reflux agent of the aqueous ballpoint pen ink according to the present invention contains 0.5 to 20 parts by weight of a styrene-based thermoplastic elastomer per 100 parts by weight of a normal temperature liquid hydrocarbon and / or silicone oil. It is of the composition shown.

The polystyrene block and the rubber block forming the styrenic thermoplastic elastomer are chemically bonded but not compatible. However, the polystyrene blocks have the property of aggregating with each other, and this serves as a physical crosslinking point, so that the polystyrene block phase and the rubber block phase form a two-phase structure. Room temperature liquid hydrocarbons and silicone oils are substances that have a high affinity for the rubber block and are easily retained in the rubber block phase. By utilizing such properties, it has become possible to satisfy all the performances required for the backflow inhibitor.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As a normal temperature liquid hydrocarbon, mineral oil, ethylene-α-olefin cooligomer, polybutene, poly-α-olefin oil and the like can be used.

As the styrene-based thermoplastic elastomer, a styrene-based thermoplastic elastomer is a polystyrene block-rubber block [X type] or a polystyrene block-rubber block-polystyrene block [Y
Type].

That is, there are the following five specific modes of use of the styrene-based thermoplastic elastomer.

One type of styrene-based thermoplastic elastomer from the X type is used. One type of styrene-based thermoplastic elastomer from Y type is used. Two or more styrene-based thermoplastic elastomers from the X type are used in combination. Two or more styrene thermoplastic elastomers from the Y type are used in combination. One or more types of X-type and one or more types of Y-type thermoplastic elastomers are used in combination.

As the rubber block, polybutadiene,
Polyisoprene, polyethylene / butylene, polyethylene / propylene are preferred.

The mixing ratio of the styrene-based thermoplastic elastomer to the normal temperature liquid hydrocarbon and / or silicone oil is based on 100 parts by weight of the normal temperature liquid hydrocarbon and the like.
It is 0.5 to 20 parts by weight. Outside this range, not all performances can be satisfied.

[0014]

EXAMPLE A water-based ink was filled in a resin ink storage tube having a ball-point pen at the tip, and a backflow inhibitor having the composition of Examples 1 to 50 shown in Table 1 below was provided at the end of the ink.

[0015]

[Table 1]

[0016]

[Table 2]

The amount of the antireflux agent in which the styrenic thermoplastic elastomer is out of the composition range of the present invention is also shown in Comparative Examples 1 to 15.
Tested as

[0018]

[Table 3]

A to E of the styrene thermoplastic elastomer used here are as follows. In addition, the following [D]
Is the X type and the others are the Y type.

[A] Styrene-butadiene-styrene block copolymer [B] Styrene-isoprene-styrene block copolymer [C] Styrene-ethylene / butylene-styrene block copolymer [D] Styrene-ethylene / propylene-block copolymer [E] Styrene -Ethylene / propylene-styrene block copolymer

The liquid hydrocarbons a to d at room temperature are as follows. [A] mineral oil [b] ethylene-α-olefin cooligomer [c] polybutene [d] poly-α-olefin oil

The performance tests performed are as follows, and the test results are shown in Table 2 below.

Impact resistance test: The sample pen was placed vertically with the pen tip up and dropped vertically from a position of 50 cm to check the state of the ink and the backflow preventive. A sample having no change in the state was evaluated as good (O), and a sample having a change such as the ejection of the ink or the dripping of the backflow preventing agent was evaluated as poor (X).

Oil separation test: The tip of the sample pen is turned up,
It was left in a thermostat at 60 ° C. for one month, and it was confirmed whether or not the oil of the backflow inhibitor was mixed into the tip of the pen and into the ink. A sample in which oil was not mixed was evaluated as good (O), and a sample in which oil was mixed was evaluated as poor (X).

Follow-up test: A writing test (writing speed: 4 m / s) was performed using a sample pen, and it was confirmed whether or not the anti-reflux agent followed as the amount of ink decreased. Those that followed were rated as good (O), those that did not follow, or those that had no backflow inhibitor during the test were rated as poor (x).

Ink blurring: A writing test (writing speed: 4 m / s) was performed using a sample pen to confirm the presence or absence of ink blurring. The case where there was no blurring of the ink was evaluated as good (○), and the case where there was blurring of the ink was evaluated as poor (×).

Drip and lateral flow phenomenon: The sample pen was left in a thermostat at 60 ° C. for one month, and the presence or absence of the backflow preventive was checked. Then, those in which the sagging and the lateral flow phenomenon were not confirmed were evaluated as good (○), and those in which they were confirmed were evaluated as poor (x).

[0028]

[Table 4]

As shown in Table 2, the results of Examples 1 to 50 obtained satisfactory results in all performance tests. On the other hand, one of Comparative Examples 1 to 15 was defective (x) after five performance tests, and all of them could not be satisfied.

[0030]

The anti-reflux agent for aqueous ball-point pen ink according to the present invention can satisfy all the required properties and is industrially useful.

Continuation of the front page (56) References JP-A-7-216285 (JP, A) JP-A-9-24689 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B43K 7 / 02 B43K 7/08 C09K 3/00

Claims (4)

(57) [Claims] An anti-reflux agent provided at an end of an aqueous ink filled in an ink container, wherein the anti-reflux agent is 0.5 to 20 parts by weight based on 100 parts by weight of a normal temperature liquid hydrocarbon and / or silicone oil. A backflow inhibitor for aqueous ball-point pen inks, characterized in that the composition comprises a styrene-based thermoplastic elastomer. 2. The room temperature liquid hydrocarbon is a mineral oil, ethylene-α-olefin cooligomer, polybutene, poly-α.
The anti-reflux agent for aqueous ballpoint pen ink according to claim 1, which is one or more olefin oils. 3. The aqueous ball-point pen ink according to claim 1, wherein the styrene-based thermoplastic elastomer contains at least one of a block copolymer consisting of a polystyrene block-rubber block or a polystyrene block-rubber block-polystyrene block. Anti-reflux agent. 4. A rubber block comprising polybutadiene, polyisoprene, polyethylene / butylene, polyethylene /
The aqueous ballpoint pen ink backflow inhibitor according to claim 3, which is any of propylene.