JPH03106975A - Marking ink for white board - Google Patents

Abstract

PURPOSE:To prolong the service life and improve the change in erasability with time by adding a specific drying preventive to an ink compsn. comprising a lower aliph. alcohol. a pigment, a butyral resin, and a liq. release agent. CONSTITUTION:A lower aliph. alcohol (e.g. ethanol) contg. 0.2% or lower water is mixed with 2-14% org. or inorg. pigment, 1-7% butyral resin, 2-25% liq. release agent (e.g. di-2-ethylhexyl phthalate), and 0.5-3.5% drying preventive comprising a nonionic wax comprising polyoxyethylene sorbitan monostearate (ethylene oxide added: 1.5-2.0mol), and the mixture is stirred at 40-60 deg.C for 30min to give a solution.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a marking ink for white boards, and more specifically, it is non-absorbable and can be applied to marking inks for plastic boards such as styrene resin, polypropylene, and vinyl. Melamine grilled board. This relates to ink for whiteboards that can be written on writing boards such as enameled boards and fluororesin films, and that can be easily erased by lightly rubbing the handwriting with a dry cloth or flexible paper. be.

(Prior Art) White board marking pens for writing on non-absorbent writing surfaces as described above are generally known. The ink composition used in white board marking pens is prepared from a low boiling point organic solvent and pigments, resins, and other release agents so that it dries quickly and leaves clear handwriting when written on a writing surface. There is.

When the cap of such a marking pen is removed from the pen tip and the pen tip is exposed to the air, in a short period of time, organic solvent is generated from the ink composition at the pen tip, and pigments and precipitated resin are released into the network structure of the pen tip. The ink becomes clogged and the flow of ink from the pen tip is obstructed, resulting in poor writing.

In recent years, the use of whiteboard marking pens has been increasing due to the use of large whiteboards instead of blackboards and the spread of electronic blackboards that allow copying due to health concerns due to the scattering of chalk powder when using blackboards. That is, white board marking pens using large white boards have been widely used in lectures, seminars, in-house research presentations, and other various meetings.

However, when a lecturer or the like uses a whiteboard marking pen to explain by writing on a whiteboard, it is rare for them to close the cap each time they finish writing, and the pen is often used with the cap removed. Therefore, the felt at the tip dries up quickly,
There may be cases where the writing lines become blurred while writing, and the lecturer or the like has to replace multiple whiteboard marking pens.

In order to solve the above problems, various types of ink compositions have been devised in the past. For example, the special public service 56-158
No. 35, Japanese Patent Publication No. 57-39666, waxes such as paraffin wax, microcrystalline wax, low-molecular polyethylene wax, ceresin, or α-olefin that melts at 30 to 80°C are added to the ink composition. However, if you remove the cap from the nib and leave it for a while, a thin film of wax will precipitate on the surface of the nib as the organic solvent evaporates, preventing this film from evaporating further. It is stated that since the film covering the tip is immediately destroyed, the outflow of the ink composition is not inhibited in any way.

(Problem to be solved by the invention) However, although the waxes used in these patents are easily soluble in toluene, they are completely insoluble in lower aliphatic alcohols. lower aliphatic alcohols, i.e. ethanol, isoprobanol, n
- Marking inks for white boards using propanol, secondary butanol, n-butanol, etc. are being replaced, and it is desirable that there is no toluene mixed in. Therefore, the above waxes cannot be used.

(Means for Solving the Problems) The present invention uses lower aliphatic alcohol as a solvent, adds wax that is slightly soluble in the alcohol, and when the cap is removed, the wax is deposited on the surface of the pen tip in the form of a thin film, and the alcohol is removed. The purpose is to suppress evaporation and prevent the pen tip from drying up for a long time. However, when writing, this thin film is easily destroyed and does not pose any problem.

We searched for various wax-like substances that are soluble in lower aliphatic alcohols, which were dissolved in isobrobanol, applied to a glass plate, evaporated, formed a film on the surface, contained a solvent, and delayed drying, and found that they were surface active. Nonionic polyoxyethylene sorbitan monostearate (1.5 to 2.0 moles of ethylene oxide), which is a type of agent
It was discovered that wax is amorphous and slightly soluble in isopropanol, and as the isopropanol evaporates, a thin film of the same wax precipitates on the surface, delaying drying. However, we were unsuccessful in inventing a marker ink for whiteboards that does not cause the felt wick to dry up for a long time even after decamping by adding this waxy substance to the ink for whiteboards.

The marking ink for whiteboards of the present invention contains polyoxyethylene sorbitan monostearate (ethylene oxide This marking ink for white boards is characterized by adding a nonionic wax having a mole number of 1.5 to 2.0 moles as an anti-drying agent.

The wax used as an anti-drying agent in the present invention is nonionic sorbitan monostearate (ethylene oxide mole number 1.5 to 2.0), and commercially available products include Nonion STN 201.5 and Nonion ST 202 (both of which are available in Japan). (made of oil and fat). The solubility in isopropanol at room temperature 20°C is Fuo STN 201.
．． 5 1.3%, ST 202 2.2%.However, since these waxes can also be blended together, the amount added is preferably 0.5 to 3.5%.
．． 0-3.0% is used.

As the pigment used in the present invention, conventionally known pigments such as organic pigments and inorganic pigments can be used as appropriate, but it is preferable to use pigments that can be stably dispersed in fine particles in the ink composition. Resin-processed pigments prepared by kneading pigment into butyral resin in a chip form at a ratio of approximately 1:1 are preferably used in the present invention, and specific examples include Fuji AS Blank 810 and Fuji AS Blue manufactured by Fuji Shikigyo Kogyo. -650, Fuji As Red 575
, Fuji AS Green 710, and the like. The amount added is 2 to 14%, preferably 6 to 10%.

As the resin used in the present invention, butyral resin is used.

The resin is preferably present in the ink composition in an amount of 1 to 7% in order to safely disperse the pigment in the ink composition and provide the ink composition with appropriate viscosity and adhesion to the writing board.
3-5% is used.

However, when using the above-mentioned processed pigment, since the butyral resin is already contained in the chip, there is no need to add any more.

Examples of the lower aliphatic alcohol used in the present invention include ethanol, isopropanol, normal, propanol, secondary butanol, and normal butanol. As a commercially available product, denatured alcohol Solmix AP-4 (Nippon Kakai) is good, and its combination or ethanol, isopropanol, acetone (85.5:
13.4: 1.1), and although some acetone, which is a denaturant, is included, it helps dissolve the butyral resin and has no adverse effect on the ink composition. Mata Solmix AP
-4 has a water content of 0.2% or less, which is advantageous because hydrous alcohol often tends to cause poor dissolution of the remover, etc. The stripping agent used in the present invention includes liquid paraffin, which is a higher aliphatic hydrocarbon that dissolves in the lower aliphatic alcohol and is a non-volatile to hardly volatile substance that is liquid at room temperature, and di-2-ethylhexyl phthalate as a phthalic acid diester. , dibutyl phthalate and polyoxyethylene alkyl ether or polyoxyethylene nonylphenyl ether or derivatives thereof, ie, phosphoric acid ester of polyoxyethylene alkyl ether or polyoxyethylene nonylphenyl ether phosphoric ester. Erasability can be imparted to handwriting by using these alone or in combination.

Such release agents are used in an amount of 2 to 25%, preferably 3 to 15%, based on the ink composition.

(Function) As mentioned above, the nonionic wax polyoxyethylene sorbitan monostearate (1.5 to 2.0 moles of ethylene oxide) used in the present invention has a solubility in alcohol of 1.3 to 2.2%. Since the concentration of wax is low, when it is added to the ink set and placed in the marker shaft to remove the cap, some of the lower aliphatic alcohol evaporates and the concentration of the above wax exceeds the saturated solution, causing a thin film of wax to precipitate on the surface of the felt core. suppresses the evaporation of group alcohols,
It is thought that this prevents the felt core from drying up for a long time. However, when writing, the formed membrane is thin and easily destroyed, so it does not interfere with writing.

The method for producing the marking ink for white boards according to the present invention is to first place the above-mentioned resin-processed pigment chip colorant in a ball mill, add lower alcohol to a solid content of 20%, and pulverize and dissolve overnight. A uniform resin-pigment dispersion is prepared, which is taken out and diluted with lower aliphatic alcohol. ) and stir to mix and dissolve.

In order to ensure complete dissolution, heating and stirring at 40 to 60°C for 30 minutes is preferred. However, the above manufacturing method is merely an example, and the manufacturing method is not limited in any way as long as a uniform kimono can be obtained.

(Example) Examples and comparative examples of the marking ink for white boards according to the present invention are shown in a table.

In the preparation of the ink composition in the examples, as in the above manufacturing method, resin-processed pigment and 4 times the amount of lower aliphatic alcohol (commercially available denatured alcohol Sol Q 7x AP-4) were placed in a ball mill and pulverized, mixed and dissolved for two nights. Then, the mixture was taken out and transferred to another container, and the remaining Solx AP-4 release agent and nonionic wax were added thereto, and the mixture was mixed and dissolved while heating at 40°C to 60°C to obtain a uniform ink composition. The various ink composition guidelines obtained in this way are shown in the table. In addition, in the table, the numbers in parentheses indicate weight percent.Next, fill these ink sets or materials into a padded marking pen with a felt nib, remove the cap, leave it horizontally in a room, and write it every hour. I drew a spiral on a white board, and the writing time was set as the time during which I could write normally within three lines even if it started to fade.However, if a marking pen is uncapped and written once, it should not be used again. The decapping writing time of the ink composition according to the present invention is 6 to 8 of that of the comparative example in which no nonionic wax is added.
doubled in length. Furthermore, the handwriting created by the ink composition of the present invention was able to be completely erased even after 81 months, equivalent to the comparative example without additives. (Effects of the present invention) As shown in the above examples, polyoxyethylene sorbitan monostearate (
Number of moles of ethylene oxide 1. By adding 5 to 2.0 mol), the writable time after decapping was significantly increased, and the erasability over time was also the same as the product without the additive in any way.

Claims (1)

[Claims] An ink composition consisting of at least a lower aliphatic alcohol, a pigment, a butyral resin, and a liquid release agent is added with a nonionic wax of polyoxyethylene sorbitan monostearate (1.5 to 2.0 moles of ethylene oxide) as an anti-drying agent. Marking ink for white boards characterized by the addition of