JP3367146B2 - Ink backflow preventive composition for ballpoint pens - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink backflow preventive composition provided above an ink in an ink storage tube, and more particularly to an impact due to a drop or the like in a high-temperature environment. The present invention relates to an ink backflow preventive composition for a ballpoint pen which minimizes outflow of ink from the rear end of an ink storage tube. 2. Description of the Related Art Conventionally, oil-based inks used for ballpoint pens have very high viscosities of several thousands to 10,000 CPS. When it is 8 (mm) or less, it is not always necessary to use the ink backflow preventive composition, but its inner diameter is 2.8 (m).
In the case of m) or more, there is a concern that ink may leak from the rear end of the ink storage tube when an impact is applied to the writing implement or when the writing implement is placed in a high-temperature environment with the pen tip facing upward. Therefore, in order to prevent this, it is known that it is necessary to provide an ink backflow preventive composition composed of vaseline, silicone grease, silicone oil, a mixture of liquid paraffin and vaseline, etc. above the ink in the ink container. [0003] In a ball-point pen using water-based ink, an ink backflow preventive composition is required for the purpose of preventing evaporation and drying of ink even in an ink container having an inner diameter of 2.8 mm or less. The ink backflow preventive composition for aqueous inks also comprises petrolatum, silicone grease, silicone oil or a mixture of liquid paraffin and petrolatum. [0004] The problem is that the ink backflow preventive composition flows out upon impact due to dropping in a high temperature environment. In a high-temperature environment such as in a car under hot weather, the viscosity of the ink backflow preventive composition is significantly reduced, and the ink tends to flow. In such a state, if an impact such as dropping is received, the ink backflow preventive composition may flow out from the rear end of the ink storage tube. In this case, there arises a problem that it becomes impossible to prevent ink leakage or to prevent drying of the ink. [0005] In order to solve the above-mentioned problems, there is a method in which the type and amount of the gelling agent are adjusted to increase the degree of gelation, and to lower the fluidity of the ink backflow preventing composition. However, in this method, in a low-temperature environment such as winter, the ink backflow preventive composition cannot follow the reduction in the amount of ink used, and the amount of ink discharged decreases, causing blurring of handwriting,
The problem that writing becomes impossible occurs. An object of the present invention is to provide an ink backflow preventive composition whose fluidity does not significantly change even in a low-temperature environment or a high-temperature environment. SUMMARY OF THE INVENTION The present invention relates to an ink backflow preventive composition provided on top of ink filled in an ink storage tube for a ballpoint pen, wherein the ink backflow preventive composition is provided. For ballpoint pens, comprising a base material made of a volatile organic liquid or a nonvolatile organic liquid selected from hydrocarbons, and a gelling agent and an ethylene α-olefin copolymer added thereto. The gist is an ink backflow preventing composition. The details will be described below. Examples of the hardly volatile organic liquid or non-volatile liquid selected from hydrocarbons as a base material used in the present invention include liquid polybutene, liquid paraffin, spindle oil, petrolatum and the like.
They can be used alone or in combination of two or more. As the gelling agent used in the present invention, in addition to the fine silica powder, a hydrogenated castor oil-based one,
Cellulose type, dextrin type, metal soaps, bentonite and the like can be mentioned. In particular, as a gelling agent, for example, if a fine particle silica powder having a primary particle size of several mμ to 50 mμ is used, the ink backflow preventive composition can exhibit a sense of transparency, as long as the ink container itself is also transparent. Good appearance can be obtained. The mixing ratio of these gelling agents is preferably 1 to 10% by weight based on the total amount of the ink backflow preventing composition. If the content is 1% by weight or less, the gelling strength of the ink backflow preventive composition becomes weak, and the ink easily flows back. If the content is 10% by weight or more, the gelling strength is too strong to follow the ink. It tends to be poor. The ethylene α-olefin copolymer makes it difficult for the ink backflow preventive composition to flow at a high temperature, and suppresses the flow of the ink backflow preventive composition from the rear end of the ink storage tube at the time of impact such as dropping. And ethylene and an α-olefin are copolymerized by an ordinary method. Specific commercial products include Orifice M-1210, PG-1010L, and L-1050.
(Above, manufactured by Mitsui Petrochemical Co., Ltd.). This ethylene α-olefin copolymer can be used alone or in combination of two or more. The copolymer is used in an amount of 0.1 to 8.0% by weight, preferably 0.5 to 2.0% by weight, based on the total amount of the ink backflow preventing composition.
When the amount is less than 0.1% by weight, the effect may be insufficient. On the other hand, when the content is more than 10% by weight, the viscosity of the backflow preventive composition becomes high, and writing at low temperatures may not be smooth. In addition to the above components, additives such as glycerin fatty acid ester and polyethylene glycol fatty acid ester can be used to prevent the ink backflow preventive composition from adhering to the inner surface of the ink storage tube. In producing the ink backflow preventive composition of the present invention, various conventionally known methods can be employed. For example, when a dextrin-based gelling agent is used, the mixture is heated and stirred (110 ° C.) with other components by a stirrer. When Aerosil is used as a gelling agent, a kneader, a roll mill, or the like is used. Can be easily obtained by mixing and grinding with other components using a dispersing machine. The ink backflow preventive composition containing an ethylene α-olefin copolymer does not need to use a large amount of a gelling agent, so that its flowability does not decrease so much even in a low temperature environment.
The ink ejection amount does not decrease. In a high-temperature environment, the ethylene α-olefin copolymer changes its molecular structure with an increase in temperature, and becomes hard to flow. On the other hand, the base material itself is reduced in viscosity due to a rise in temperature, and is in a state of being easy to flow. For this reason, as a whole ink backflow prevention body composition,
Fluidity does not change. Therefore, the ink backflow preventive composition does not flow out of the ink storage tube even in the present high-temperature environment, and does not lower the ink discharge even in the low-temperature environment. Hereinafter, the present invention will be described in more detail with reference to examples. Example 1 Liquid polybutene (Polybutene HV-15, manufactured by Nippon Oil Co., Ltd.) 92.9 parts by weight Fine silica powder (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.) 4.0 parts by weight Dextrin fatty acid ester (Leopa- 2.0 parts by weight of ethylene α-olefin copolymer (containing Orfus PG-1010L and 15% by weight of ethylene α-olefin copolymer, manufactured by Mitsui Petrochemical Co., Ltd.) 1 part by weight glyceryl dioleate (DGO-80, manufactured by Nikko Chemicals Co., Ltd.) 1.0 part by weight The above components were put into a kneader, and the mixture was stirred for 2 to 3 hours to obtain an ink backflow preventive composition for a ballpoint pen. . Example 2 92.0 parts by weight of liquid polybutene (polybutene HV-15) 4.0 parts by weight of fine silica powder (Aerosil R-972) 2.0 parts by weight of dextrin fatty acid ester (Leopar KE) ethylene α- Olefin copolymer (Orfuse PG-1010L) 1.0 part by weight Glyceryl dioleate (DGO-80) 1.0 part by weight Put the above components in a kneader, stir for 2 to 3 hours, and prevent ink from flowing back for ballpoint pen. A composition was obtained. Example 3 Liquid polybutene (polybutene HV-15) 85.0 parts by weight Fine silica powder (Aerosil R-972) 4.0 parts by weight Dextrin fatty acid ester (Leopar KE) 2.0 parts by weight Ethylene α- Olefin copolymer (Orfuse PG-1010L) 8.0 parts by weight Glyceryl dioleate (DGO-80) 1.0 part by weight The above-mentioned components are put into a kneader, and the mixture is stirred for 2 to 3 hours. A composition was obtained. Example 4 92.0 parts by weight of liquid polybutene (polybutene HV-15) 4.0 parts by weight of fine silica powder (Aerosil R-972) 2.0 parts by weight of dextrin fatty acid ester (Leopar KE) 2.0 parts by weight of ethylene α- Olefin copolymer (Orfuth M-1210, containing 16% by weight of ethylene α-olefin copolymer, manufactured by Mitsui Petrochemical Co., Ltd.) 1.0 part by weight Glyceryl dioleate (DGO-80) 1.0 part by weight The components were placed in a kneader and stirred for 2 to 3 hours to obtain an ink backflow preventive composition for a ballpoint pen. Example 5 92.2 parts by weight of liquid polybutene (polybutene HV-15) 4.0 parts by weight of fine silica powder (Aerosil R-972) 2.0 parts by weight of dextrin fatty acid ester (Leopar KE) 2.0 parts by weight of ethylene α- Olefin copolymer (Orfuth L-1050, containing 20% by weight of ethylene α-olefin copolymer, manufactured by Mitsui Petrochemical Co., Ltd.) 0.8 part by weight Glyceryl dioleate (DGO-80) 1.0 part by weight The components were placed in a kneader and stirred for 2 to 3 hours to obtain an ink backflow preventive composition for a ballpoint pen. Comparative Example 1 Liquid polybutene (polybutene HV-15) 93.0 parts by weight Fine silica powder (Aerosil R-972) 4.0 parts by weight Dextrin fatty acid ester (Leopar KE) 2.0 parts by weight Glyceryldiole 1.0 part by weight of Eate (DGO-80) The above components were placed in a kneader and stirred for 2 to 3 hours to obtain an ink backflow preventive composition for a ballpoint pen. Comparative Example 2 Liquid polybutene (polybutene HV-15) 86.0 parts by weight Fine silica powder (Aerosil R-972) 11.0 parts by weight Dextrin fatty acid ester (Leopar KE) 2.0 parts by weight Glyceryldiolet 1.0 part by weight of Eate (DGO-80) The above components were placed in a kneader and stirred for 2 to 3 hours to obtain an ink backflow preventive composition for a ballpoint pen. [0020] An ink container tube (material: polypropylene, inner diameter 3.2 m) with a nickel-white ballpoint pen tip attached to one end
In m), 0.8 g of a water-based ink having a composition described later and having a viscosity of 2000 cps was filled, and the upper part of the ink (opposite the ballpoint pen tip) was subjected to the reverse flow of the ink obtained in Examples 1 to 5 and Comparative Examples 1 and 2. 0.1 g of each of the inhibitor compositions is filled,
Centrifugal defoaming was performed to prepare a test ballpoint pen replacement core. Place the test ballpoint pen replacement core in a constant temperature room at 50 ° C and 0 ° C.
After standing for 2 hours, a drop test and a writing test were performed. Table 1 shows the results. [Table 1] (Evaluation criteria) Drop test ；; no change 逆; no backflow prevention body leaked out of ink storage tube,
Ink has been mixed into the backflow preventer. ×: The backflow preventer flows out of the ink storage tube. Writing test ；: Good writing is possible △; Fainting occurs at the time of fast writing ×; Writing is not possible Drop test: Dropping the pen tip upward from a height of 1.5 m, and ink flowing backward after falling The state of the inhibitor composition was visually observed. Writing test: high quality paper (JIS P3201)
Writing was performed by hand on paper (paper conforming to the writing paper A). Usually, the writing speed is 7 cm / min, and the fast writing is 10 cm / min. (Composition of water-based ink) Ion-exchanged water 35.78 parts by weight Fluorescent pigment (NKW-3004, manufactured by Nippon Fluorescent Co., Ltd.) 45.00 parts by weight Ethylene glycol 12.00 parts by weight Glycerin 5.00 parts by weight Preservative (Proxel GXL, manufactured by ICI Japan KK) 0.20 parts by weight Rust inhibitor (benzotriazole) 0.02 parts by weight Carboxymethylcellulose 2.00 parts by weight (Effect of the Invention) Ink for ballpoint pen in the present invention The backflow preventive composition has no outflow of the backflow composition due to a drop impact in a high-temperature environment, sufficiently achieves the object as the ink backflow preventive composition, and does not decrease in fluidity even in a low-temperature environment. This is a useful material that can sufficiently achieve the intended purpose, that is, there is almost no reduction in ink ejection. In the test, a water-based ink was used as an example of a ball-point pen. However, it goes without saying that the same effect can be obtained with an oil-based ink.

Continuation of the front page (56) References JP-A-61-57673 (JP, A) JP-A-61-268786 (JP, A) JP-A-62-50379 (JP, A) JP-A-5-117681 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B43K 7/02 C09K 3/00

Claims (1)

(57) [Claim 1] An ink backflow preventing composition provided on top of ink filled in an ink storage tube for a ballpoint pen, wherein the ink backflow preventing composition is carbonized. Backflow ink for a ballpoint pen, comprising a base material made of a volatile organic liquid or a non-volatile organic liquid selected from hydrogens, and a gelling agent and an ethylene α-olefin copolymer added thereto. Inhibitor composition.